An improved method for quality control of in situ data from Argo floats using α convex hulls.

An improved method for detecting abnormal oceanic in situ temperature and salinity (T/S) profiles is developed. This procedure extends previous method developed by Udaya Bhaskar et al. [2017]. This method utilizes World Ocean Atlas 2013 gridded climatology which is on 0.25° x 0.25° resolution to build α convex hulls. These α shapes are then used to categorize good and bad in situ T/S data profiles. This extended method classify the entire profiles instead of data for standard depths to avoid any errors introduced by interpolation to standard depths. Like in previous method, an 'n' sided polygon (convex hull) encompassing the T/S profile data is constructed using Jarvis March algorithm and Points In Polygon (PIP) principle is employed to judge the profile as good or bad. Extensive sensitivity experiments were done for arriving at the optimal α value such that false positives and true negatives are minimized. All types of issues associated with the in situ oceanographic data are identified and quality flag assigned. Examples of this improved method as applied to few Argo floats are presented.•The T/S profiles corresponding to region of interest are used to build α convex hulls.•This extended method can be effectively used for quality control of entire profile and clearly demarcate the profile as good/bad.•This method has the advantage of treating bulk of oceanographic in situ profiles data in a single go which filters out erroneous profile data from the good.

In Situ FTIR Spectroscopic Monitoring of the Formation of the Arene Diazonium Salts and its Applications to the Heck-Matsuda Reaction.

This study depicts the use of a fiber-optic coupled Fourier transform infrared spectroscopy-attenuated total reflection (FTIR-ATR) probe for the in-depth study of arene diazonium salt formation and their utilization in the Heck-Matsuda reaction. The combination of these chemical reactions and in situ IR spectroscopy enabled us to recognize the optimum parameters for arene diazonium salt formation and to track the concentrations of reactants, products and intermediates under actual reaction conditions without time consuming HPLC analysis and the necessity of collecting the sample amid the reaction. Overall advantages of the proposed methodology include precise reaction times as well as identification of keto enol tautomerization in allylic alcohols supporting the 'path a' elimination mechanism in the Heck-Matsuda reaction.

Differentiation of the diastereomeric synthetic precursors of isofebrifugine and febrifugine by electrospray ionization tandem mass spectrometry.

Febrifugine is an alkaloid with potent antimalarial activity isolated from Dichroa febrifuga and Hydrangea umbellate, and it exists naturally with its diastereomeric component, isofebrifugine. Here we report the differentiation of diastereomeric synthetic precursors of isofebrifugine (1, cis) and febrifugine (2, trans) and a structurally similar model diastereomeric pair without a halogen substituent (3 and 4) by electrospray ionization (ESI) tandem mass spectrometry. Compounds 1-4 contain a tert-butoxycarbonyl (BOC) substituent, and the collision-induced dissociation (CID) spectra of the [M+H](+), [M+Na](+) and [M+Li](+) ions of 1-4 include the expected product ions corresponding to the loss of C(4)H(8) (isobutene) and of C(5)H(8)O(2) (BOC-H). Loss of C(5)H(8)O(2) is dominant in cis isomers (1 and 3) and/or loss of C(4)H(8) ions is dominant in trans isomers (2 and 4). The decomposition of [M+H](+) ions shows stereoselectivity in the formation of the [M+H-(BOC-H)-C(3)H(5)OBr](+) and [M+H-(BOC-H)-C(6)H(5)CH(2)OH](+) ions. The [M+Cat](+) ions (where Cat = Na or Li) additionally show loss of NaBr and HBr from [M+Cat-(BOC-H)](+), and these product ions are constantly more abundant in cis isomers than in trans isomers. The stereoselectivity for the product ion corresponding to the loss of [(BOC-H)+C(3)H(5)OBr] from [M+H](+) ions differs from that from [M+Cat](+) ions.

Effect of posterior tenectomy of the superior oblique on objective and subjective torsion in cases of superior oblique overaction.

PURPOSE: To evaluate the effect of posterior tenectomy of the superior oblique on the correction of A-pattern, superior oblique overaction and the changes in torsion that occur in such cases. PATIENTS AND METHODS: This prospective study included 15 consecutive cases of bilateral superior oblique overaction with an A-pattern of more than 20 PD, a difference of deviation between 25 degrees up-gaze and 35 degrees downgaze, and superior oblique overaction of 2+ to 3+ on a scale of 0 to 4+. Deviation was measured in the primary position, 25 degrees upgaze, and 35 degrees downgaze using the prism bar cover test, and torsion was measured using a synoptophore, the double Maddox rod test, and fundus photographs. Measurements were obtained preoperatively and postoperatively at 1 week, 1 month, and 3 months. All case-patients underwent a standard temporal route posterior tenectomy of the superior oblique by a single surgeon. RESULTS: Mean age was 11.2 +/- 4.2 years with 14 cases of A-pattern exotropia. Mean superior oblique overaction was 2.60 +/- 0.50 in the right eye and 2.26 +/- 0.45 in the left eye, which decreased postoperatively to 2.20 +/- 0.56 and 1.80 +/- 0.41, respectively. The index of surgical effect was 0.84 in the right eye and 0.79 in the left eye. Postoperatively, mean correction of the A-pattern was 17.53 +/- 5.82 PD (index of surgical effect, 0.7). Subjective measurement of torsion was more consistent with the synoptophore compared with the double Maddox rod test. Objective measurement of torsion (fundus photography) was higher compared with subjective measurement. Postoperatively, there was insignificant change in the amount of torsion in upgaze and primary position. CONCLUSION: Posterior tenectomy of the superior oblique results in significant and controlled weakening of the superior oblique and collapse of the A-pattern with a clinically insignificant change in the amount of torsion.

A short, stereoselective, and common approach for the synthesis of 4,5-disubstituted delta-lactones simplactone B and its C-5 analogue.

A short, stereoselective, and a common approach for the synthesis of 4,5-disubstituted delta-lactones simplactone B and its analogue using Evans protocol is described.