Hydrophobically Modified Poly(acrylic acid) Using 3‐Pentadecylcyclohexylamine: Synthesis and Rheology

Summary: Hydrophobically modified poly(acrylic acid) was synthesized using 3‐pentadecylcyclohexylamine (3‐PDCA), which was in turn synthesized from 3‐pentadecylphenol, one of the components of cashew‐nut shell liquid (CNSL), a renewable resource material. ¹H NMR spectra confirmed the incorporation of 3‐PDCA onto PAA and a series of HMPs with three different molar concentrations, viz ? 3, 5 and 7 mol‐% of 3‐PDCA, were synthesized. An increase in viscosity with increasing hydrophobic content was observed by rheological measurements. The critical association concentrations were determined using an Ubbelohde viscometer and a controlled stress rheometer. The stability of HMPs towards temperature and shear was studied. Rheological measurements showed that there was a steady increase in viscosity with increase in hydrophobe content due to the formation of reversible networks. These polymers exhibited gel‐like behavior at low concentrations (≥2 wt.‐%) with an apparent yield stress (ca. 10 Pa) and showed shear thinning properties (non‐Newtonian). However, below a critical concentration, c [η], they showed Newtonian behavior.

η_sp of unmodified and modified PAA‐Na at various polymer concentrations.     

Is patient age associated with risk of malignancy in a ≥4 cm cytologically benign thyroid nodule?

BackgroundCurrent data regarding the risk of malignancy in a large thyroid nodule with benign fine-needle aspiration biopsy(FNAB) is conflicting. We investigated the impact of patient age on the risk of malignancy in nodules≥4 cm with benign cytology.MethodsWe performed a single-institution retrospective review of patients who underwent surgery from 07/2008–08/2019 for a cytologically benign thyroid nodule ≥4 cm. The relationship between malignant histopathology and patient and ultrasound features was assessed with multivariable logistic regression.ResultsOf 474 nodules identified, 25(5.3%) were malignant on final pathology. In patients <55 years old, 21/273(7.7%) nodules were malignant, compared to 4/201(2.0%) in patients ≥55. Patient age ≥55 was independently associated with significantly lower risk of malignancy(OR:0.2,95%CI:0.1–0.7,p = 0.011). Increasing nodule size >4 cm and high-risk ultrasound features were not associated with risk of malignancy(OR:1.0,95%CI:0.7–1.4,p = 0.980, and OR:9.6,95%CI:0.9–107.8,p = 0.066, respectively).ConclusionsPatients <55 years old are 3.7-fold more likely to have a falsely benign FNA biopsy in a nodule≥4 cm.     

Association between age and disease specific mortality in medullary thyroid cancer

BackgroundThe aim of this study was to evaluate the association between age and disease specific mortality (DSM) among adults diagnosed with medullary thyroid cancer (MTC).MethodSurveillance, Epidemiology, and End Results (SEER-18) was used to analyze adult MTC patients stratified by age (18–64, 65–79, ≥80 years). Associations between patient demographics, tumor size, nodal status, metastatic disease, and extent of surgery on DSM was assessed with multivariable Cox regression.ResultsAmong 1457 patients with MTC, 1008 (69.2%) were younger adults, 371 (25.5%) older adults, and 78 (5.4%) were super-elderly. A significantly higher proportion of older adults and super-elderly had less than the recommended operation for MTC. On multivariable analysis, older adults and super-elderly were 2.9 and 6.7 times more likely to have an increased DSM (HR:2.91, 95% CI: 1.83–4.63; p < 0.001 and HR: 6.70, 95%CI: 3.69–12.20; p < 0.001). Extent of surgery or lymphadenectomy did not affect DSM.ConclusionsIncreased age is an independent predictor of DSM in patients with MTC.     

Oligo-glycerol based non-ionic amphiphilic nanocarriers for lipase mediated controlled drug release

A new class of non-ionic amphiphiles is synthesized using a diaryl derivative of diglycerol as a central core and functionalizing it with long alkyl chains (C-12/C-15) and monomethoxy PEG moiety (M_n: 350/550) by following a chemo-enzymatic approach. The aggregation behavior of the amphiphiles in aqueous medium is studied by using dynamic light scattering (DLS) and fluorescence spectroscopy, whereas the size and morphology of the aggregates are studied by transmission electron microscopy (TEM). A hydrophobic dye, Nile red and a hydrophobic drug, nimodipine, are used to demonstrate the nano-carrier capability of these non-ionic amphiphilic systems and the results are compared with amphiphilic analogues obtained from the triaryl derivatives of triglycerol. The in vitro controlled release of the encapsulated dye is successfully carried out in the presence of immobilized Candida antarctica lipase (Novozym 435). Furthermore, cytotoxicity data is also collected which suggests that the amphiphiles are suitable for biomedical applications.

A new series of oligo-glycerol based amphiphiles have been synthesized for drug delivery.     

A prolonged observational study of tracheal tube displacements: Benchmarking an incidence <0.5-1% in a medical-surgical adult intensive care unit

Background and Aims:

Tracheal tubes are commonly used in intensive care unit (ICU) and lead to complications like displacements. The primary aim of the study was to evaluate if the rate of tracheal tube displacement benchmarked at <1% per patient and <0.5% per tracheal tube day, could be sustained over a prolonged period. The secondary aim was to document the patterns of all forms airway accident and to evaluate their consequences.

Subjects and Methods:

This was a prospective observational study of Intubated and ventilated patients in a General Medical-Surgical Adult ICU. The incidence of accidental extubation, self extubation, partial displacement and blockages of tracheal tubes were recorded.

Results:

The overall tracheal tube displacement rate was 61/10,112 (0.6%) per patient and 61/28,464 (0.22%) per tracheal tube day. There were 30 additional incidents of blockage, kinking or biting of the tracheal tube. Physiological consequences-69 were mild, 10 moderate, 12 major and one death. Of the 91 accidents, 30 were partly and 30 were completely preventable. 76 incidents involved an endotracheal tube (54 displaced, 12 blocked and 10 bitten-kinked) and 15 a tracheostomy tube (seven displaced and eight blocked). Accidents were more common in medical than surgical patients (medical = 48, cardiac surgical = 17 and other surgical/trauma = 26).

Conclusion:

Tracheal tube displacement rate in a mixed medical-surgical adult ICU was maintained below the pre-set benchmark of <1% per patient and <0.5% per intubated day over nearly a decade.