Individualization of vancomycin dosing based on therapeutic drug monitoring (TDM) data is known to improve patient outcomes compared with fixed or empirical dosing strategies. There is increasing ...evidence to support area-under-the-curve (AUC24)-guided TDM to inform vancomycin dosing decisions for patients receiving therapy for more than 48 hours. It is acknowledged that there may be institutional barriers to the implementation of AUC24-guided dosing, and additional effort is required to enable the transition from trough-based to AUC24-based strategies. Adequate documentation of sampling, correct storage and transport, accurate laboratory analysis, and pertinent data reporting are required to ensure appropriate interpretation of TDM data to guide vancomycin dosing recommendations. Ultimately, TDM data in the clinical context of the patient and their response to treatment should guide vancomycin therapy. Endorsed by the International Association of Therapeutic Drug Monitoring and Clinical Toxicology, the IATDMCT Anti-Infectives Committee, provides recommendations with respect to best clinical practice for vancomycin TDM.
Summary The submental artery island flap (SIF) is gaining acceptance as a simple and reliable option in selected oral oncologic reconstructions. The present study aims to assess the usefulness of ...submental artery flap in oral reconstruction with respect to flap reliability, cosmesis, function, donor site morbidity and oncological safety. Thirty (30) patients who underwent ablative surgery and reconstruction using the submental artery island flap for oral cancer at Regional Cancer Centre, Trivandrum, India, between October 2004 and December 2006 were prospectively studied for the flap viability, cosmesis, function (speech and swallowing) and locoregional recurrence. The site and stage of the tumour, type of resection, management of the neck and the technique of flap transfer were recorded and the patients were followed up to assess the status of the flap and its donor site and the oncologic outcomes. There were 19 men and 11 women, ages of whom ranged from 30 years to 78 years with a mean ± SD of 53 ± 11 years. With the exception of one patient who had undergone neck dissection as part of a previous surgery, all patients underwent neck dissection or at least a level I clearance along with the wide excision of the primary lesion. The follow up period ranged from 4 to 25 months with a median of 13.5 months. Six patients either recurred locoregionally or had metachronous second primary constituting an over all recurrence rate of 20%. The size of the skin paddle ranged from 3 × 3 cm to 7 × 6 cm, with a mean size of 4.9 × 4 cm. One total and one partial flap loss were observed. One patient had intractable hair growth on the flap even 3 months after surgery. Donor site healing was excellent in all cases and the donor site scar was well hidden. The long term cosmesis and functions were good in all the patients. The submental artery island flap is a simple and reliable option for oral cancer reconstruction in carefully selected cases, with acceptable cosmetic and functional results and reasonable oncological safety.
The influence of propargyl groups on the thermal polymerization of phthalonitrile groups has been examined through reaction of a blend of a bisphthalonitrile viz. 2,2-bis(4-phthalonitrile oxy ...phenyl)propane and a bispropargyl ether viz. 2,2-bis(4-proparyloxy phenyl)propane (BPhPR). The possibilities for co-reaction of the propargyl and phthalonitrile moieties and/or the catalytic nature of the cure reaction prevailing in their blends were indicated by multiple exotherms in differential scanning calorimetry and dynamic rheological experiments. These have been attributed to homopolymerization of propargyl, hydroxyl and chromene mediated nitrile polymerization. FT-IR and fluorescence emission spectroscopic investigations on model compounds confirmed that nitrile polymerization was favoured by the chromene and hydroxyl groups formed by Claisen rearrangement. Activation energy of the reaction step involving chromene mediated phthalonitrile crosslinking was found to be 89 kJ/mol which was close to the value of phenol catalysed phthalonitrile curing.
Flowering exhibits a significant relationship with environmental stimuli and changes. Effect of photoperiodism and vernalization have been well studied in flowering phenology; however, the effect of ...soil temperature on flowering is less explored which is one of the major factors of vegetation growth in alpine ecosystem. This study thus focuses on the effects of soil and air temperature on flowering response of
Rhododendron arboreum
Sm., a Himalayan tree species, which is also an indicator of spring initiation in high altitude regions. To monitor the flowering pattern, we employed automated phenocam, which was set up at 3356 masl in Tungnath (Indian Alpine region of Uttarakhand) for time-lapse photography of timberline ecotone. Soil and air temperature were recorded continuously at the timberline ecotone. Three years (2017 to 2020) of datasets were used for the present study. The phenocam observations displayed an interesting event in the year 2019–2020 with complete absence of flowering in
R. arboreum
population at Tungnath timberline ecotone. From the soil temperature data, an increase in winter (Dec–Jan, during which floral buds form) soil temperature, by > 1 °C, and no accumulation of freezing degree-days were found for the year 2019–2020. Air temperature however did not display any relationship with the failure of flowering, ruling out aerial chilling or frost injury of floral buds. From the results, a possible relationship between soil temperature and flowering can be suggested pointing towards necessary root apex vernalization stimulus in shallow rooted
Rhododendrons
. However, the dependency of flowering in
Rhododendrons
on winter soil temperature further requires continuous monitoring and more observations to make concrete inferences.
Intraseasonal variations (ISV) of sea surface temperature (SST) in the Bay of Bengal (BoB) is highest in its northwestern part. An Indian Ocean model forced by QuikSCAT winds and climatological river ...discharge (QR run) reproduces ISV of SST, albeit with weaker magnitude. Air‐sea fluxes, in the presence of a shallow mixed layer, efficiently effect intraseasonal SST fluctuations. Warming during intraseasonal events is smaller (<1°C) for June ‐ July period and larger (1.5° to 2°C) during September, the latter due to a thinner mixed layer. To examine the effect of salinity on ISV, the model was run by artificially increasing the salinity (NORR run) and by decreasing it (MAHA10 run). In NORR, both rainfall and river discharge were switched off and in MAHA10 the discharge by river Mahanadi was increased tenfold. The spatial pattern of ISV as well as its periodicity was similar in QR, NORR and MAHA10. The ISV was stronger in NORR and weaker in MAHA10, compared to QR. In NORR, both intraseasonal warming and cooling were higher than in QR, the former due to reduced air‐sea heat loss as the mean SST was lower, and the latter due to enhanced subsurface processes resulting from weaker stratification. In MAHA10, both warming and cooling were lower than in QR, the former due to higher air‐sea heat loss owing to higher mean SST, and the latter due to weak subsurface processes resulting from stronger stratification. These model experiments suggest that salinity effects are crucial in determining amplitudes of intraseasonal SST variations in the BoB.
Key Points
Salinity effects control the amplitude of intraseasonal SST variations
Intraseasonal SST variations are larger during the later part of the monsoon
When the Bay of Bengal salinity is higher intraseasonal variations is larger
Self cure promoting, amine-containing novolac–phthalonitrile (APN) resins of varying compositions were synthesized and characterized. APN possessing amine functionalities reduced the cure initiation ...temperature from 310 °C (typical of pure phthalonitrile systems) to 180 °C. It showed excellent thermal stability up to 420 °C and high char residue of 77–79 %. Co-reaction of APN with diglicydyl ether of bisphenol A (DGEBA) led to a decrement in their thermal stability though improved their adhesive properties. Evidences were obtained for epoxy–amine, epoxy–phthalonitrile and amine–phthalonitrile reactions. The latter reactions led to formation of oxazoline, triazine and phthalocyanine groups in the network. These were rationalized by density functional theory studies on model compounds. The extents of epoxy–amine and epoxy–phthaonitrile reactions were quantified. Introduction of hydroxyl terminated poly ether ether ketone (PEEK) reduced the brittleness of the blends and improved their lap shear strength. Toughening of epoxy–amino novolac phthalonitrile networks occurred through phase separation of PEEK segments in cured matrix.
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•Synthesis and characterization of novel self cure promoting, amino–novolac–phthalonitrile resin (APN).•Achieved significant reduction in cure temperature.•Realized polymer networks with higher thermal stability.•Altering the cure reaction of APN by way of epoxy–amine and epoxy–phthalonitrile reactions.•First time report on PEEK-toughened phthalonitrile systems and their adhesive properties.
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•First time report on one component propargyl–phthalonitrile thermosets.•Propargyl mediated nitrile curing is established in an oligomer system.•Phthalocyanine, triazine, and chromene ...structures are identified in cured resin.•Compositional dependency on thermal stability and crosslinking established.
Novolac polymers bearing varying proportions of propargyl and phthalonitrile groups on the same backbone and capable of self and co-curing to a thermally stable matrix have been synthesized. Spectral and thermal studies gave evidence for both homopolymerization of propargyl groups and its co-reaction with nitrile groups during thermal curing. Propargyl groups promoted curing of phthalonitrile groups through the hydroxyl and chromene intermediates formed from the thermal cyclization reactions of this group. Resins rich in propargyl groups showed higher crosslink density and higher modulus values. Among the copolymers, phthalonitrile rich systems exhibited relatively higher thermal stability with initial decomposition temperature at around 435°C. All the cured compositions showed anaerobic char yields of 73–76% at 900°C.
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