Hydrophobic deep eutectic solvents (DESs) are a new generation of water immiscible solvents that have been presented in the literature for the first time in 2015. These solvents have been used for ...many applications. Here, an overview is given regarding hydrophobic DESs with their physicochemical properties, applications, and the challenges and limitations that the field currently is experiencing. First, a general introduction and an introduction to hydrophobic DESs are presented to explain more about DESs, their origin, and hydrophobic ones. Here, also, an overview of all the hydrophobic DESs presented in the literature is given. After the introduction, physicochemical properties such as density, viscosity, melting point, degradation temperature, volatilities, and solvatochromic properties are discussed. It is continued with the discussion of 21 different applications of hydrophobic DESs. In general, applications related to liquid–liquid extractions, liquid–liquid microextractions, formation of two and three phase systems, removal of components from leaves, gas–liquid extractions, formation of hydrogels, membrane formation, centrifugal partition chromatography, formation of a ferrofluid, coating, photoluminescence, and dye-sensitized solar cells, and catalysis have been investigated. Finally, challenges and limitations of hydrophobic DESs are discussed.
Deep eutectic solvents (DESs) based on terpenes are identified and characterized. 507 combinations of solid components are tested, which results in the identification of 17 new hydrophobic DESs. Four ...criteria are introduced to assess the sustainability of these hydrophobic DESs from a chemical engineering point of view. These criteria include a viscosity smaller than 100 mPa·s, a density difference between DES and water of at least 50 kg·m–3 upon mixing of the DES and water, low transfer of the DES to the water phase and minor to no pH change. The results show that five new hydrophobic DESs based on natural components satisfy these criteria; thymol and coumarin (2:1), thymol and menthol (1:1), thymol and coumarin (1:1), thymol and menthol (1:2) and 1-tetradecanol and menthol (1:2), and thus are promising DESs. These new DESs can be considered as natural deep eutectic solvents, which have the potential to be environmentally friendly. A selected group of the hydrophobic DESs were used for the extraction of riboflavin from water. They all show higher removal of riboflavin in comparison to decanoic acid:tetraoctylammonium bromide (2:1). The highest extraction efficiency of riboflavin from water, 81.1%, was achieved with the hydrophobic DES DecA:Lid (2:1).
We review the standard nitrogen dioxide (NO2) data product (Version 1.0.), which is based on measurements made in the spectral region 415–465 nm by the Ozone Monitoring Instrument (OMI) on the NASA ...Earth Observing System‐Aura satellite. A number of ground‐ and aircraft‐based measurements have been used to validate the data product's three principal quantities: stratospheric, tropospheric, and total NO2 column densities under nearly or completely cloud‐free conditions. The validation of OMI NO2 is complicated by a number of factors, the greatest of which is that the OMI observations effectively average the NO2 over its field of view (minimum 340 km2), while a ground‐based instrument samples at a single point. The tropospheric NO2 field is often very inhomogeneous, varying significantly over tens to hundreds of meters, and ranges from <1015 cm−2 over remote, rural areas to >1016 cm−2 over urban and industrial areas. Because of OMI's areal averaging, when validation measurements are made near NO2 sources the OMI measurements are expected to underestimate the ground‐based, and this is indeed seen. Further, we use several different instruments, both new and mature, which might give inconsistent NO2 amounts; the correlations between nearby instruments is 0.8–0.9. Finally, many of the validation data sets are quite small and span a very short length of time; this limits the statistical conclusions that can be drawn from them. Despite these factors, good agreement is generally seen between the OMI and ground‐based measurements, with OMI stratospheric NO2 underestimated by about 14% and total and tropospheric columns underestimated by 15–30%. Typical correlations between OMI NO2 and ground‐based measurements are generally >0.6.
The solubility of CO2 in hydrophobic deep eutectic solvents (DESs) has been measured for the first time. Six different hydrophobic DESs are studied in the temperature range from 298 to 323 K and at ...CO2 pressures up to 2 MPa. The results are evaluated by comparing the solubility data with existing hydrophilic DESs and currently applied physical solvents and fluorinated ionic liquids. The DESs are prepared by mixing decanoic acid with a quaternary ammonium salt with different halide anions and alkyl chain lengths. The measured CO2 solubilities are similar to those found in renowned fluorinated ILs, while the heats of CO2 absorption are in the range of nonpolar solvents. The presented DESs show good potential to be used as CO2 capture agents.
In this retrospective study we compared the clinical outcome of early vs delayed excision of lymph node metastases in patients with penile squamous cell carcinoma.
A total of 40 patients with a T2–3 ...penile carcinoma with lymph node metastases were included in this study. All patients initially presented with bilateral impalpable lymph nodes. In 20 patients (50%) metastases were removed when they became clinically apparent during meticulous followup (median interval 6 months, range 1 to 24). There were 20 patients (50%) who underwent resection of inguinal metastases detected on dynamic sentinel node biopsy before they became palpable. The histopathological characteristics of the tumors and lymph nodes were reevaluated.
The 2 populations were similar in terms of patient age, T-stage, pathological tumor grade, vascular invasion and infiltration depth. Disease specific 3-year survival of patients with positive lymph nodes detected during surveillance was 35% and in those who underwent early resection, 84% (log rank p = 0.0017). In multivariate analysis early resection of occult inguinal metastases detected on dynamic sentinel node biopsy was an independent prognostic factor for disease specific survival (p = 0.006).
Early resection of lymph node metastases in patients with penile carcinoma improves survival.
In this study, the influence of the TiCl4 post-treatment on nanocrystalline TiO2 films as electrodes in dye-sensitized solar cells is investigated and compared to nontreated films. As a result of ...this post-treatment cell efficiencies are improved, due to higher photocurrents. On a microscopic scale TiO2 particle growth on the order of 1 nm is observed. Despite a corresponding decrease of BET surface area, more dye is adsorbed onto the oxide surface. Although it seems trivial to match this finding with the improved photocurrent, this performance improvement cannot be attributed to higher dye adsorption only. This follows from comparison between incident photon to current conversion efficiency (IPCE) and light absorption characteristics. Since the charge transport properties of the TiO2 films are already more than sufficient without treatment, the increase in short circuit current density J SC cannot be related to improvements in charge transport either. Transient photocurrent measurements indicate a shift in the conduction band edge of the TiO2 upon TiCl4 treatment. It is concluded that the main contribution to enhanced current originates from this shift in conduction band edge, resulting in improved charge injection into the TiO2.
Summary
Background Thyroid disease has been suggested to be associated with vitiligo. However, the outcomes of prevalence studies on thyroid disease in vitiligo vary widely.
Objectives To summarize ...and critically appraise current evidence of the prevalence of thyroid diseases in vitiligo.
Methods A systematic review was performed searching the electronic databases OVID MEDLINE, OVID EMBASE and PubMed. Guidelines for the critical appraisal of studies on prevalence of a health problem were adapted to evaluate the methodological quality of the included studies. Results were analysed in a meta‐analysis with a risk ratio (RR).
Results Forty‐eight studies published between 1968 and 2012 met the inclusion criteria. Most of the studies (50%) were of fair methodological quality, whereas 18 studies (38%) were of poor quality and six studies (12%) were of good quality. Thyroid disease, autoimmune thyroid disease and presence of thyroid‐specific autoantibodies showed a mean prevalence of, respectively, 15·1%, 14·3% and 20·8% in patients with vitiligo and an RR of, respectively, 1·9, 2·5 and 5·2 (all statistically significant). This review shows an increased prevalence and an increased risk of (autoimmune) thyroid disease in patients with vitiligo compared with nonvitiligo. This risk seems to increase with age.
Conclusions Clinicians should be aware of this increased risk in patients with vitiligo and should be attentive for symptoms of thyroid disease. To make recommendations on screening for thyroid disease in patients with vitiligo future research of good methodological quality, including differentiation of vitiligo types and the use of standardized outcome measures, is needed.
Since publication of the European League Against Rheumatism (EULAR) recommendations for management of hand osteoarthritis (OA) in 2007 new evidence has emerged. The aim was to update these ...recommendations. EULAR standardised operating procedures were followed. A systematic literature review was performed, collecting the evidence regarding all non-pharmacological, pharmacological and surgical treatment options for hand OA published to date. Based on the evidence and expert opinion from an international task force of 19 physicians, healthcare professionals and patients from 10 European countries formulated overarching principles and recommendations. Level of evidence, grade of recommendation and level of agreement were allocated to each statement. Five overarching principles and 10 recommendations were agreed on. The overarching principles cover treatment goals, information provision, individualisation of treatment, shared decision-making and the need to consider multidisciplinary and multimodal (non-pharmacological, pharmacological, surgical) treatment approaches. Recommendations 1-3 cover different non-pharmacological treatment options (education, assistive devices, exercises and orthoses). Recommendations 4-8 describe the role of different pharmacological treatments, including topical treatments (preferred over systemic treatments, topical non-steroidal anti-inflammatory drugs (NSAIDs) being first-line choice), oral analgesics (particularly NSAIDs to be considered for symptom relief for a limited duration), chondroitin sulfate (for symptom relief), intra-articular glucocorticoids (generally not recommended, consider for painful interphalangeal OA) and conventional/biological disease-modifying antirheumatic drugs (discouraged). Considerations for surgery are described in recommendation 9. The last recommendation relates to follow-up. The presented EULAR recommendations provide up-to-date guidance on the management of hand OA, based on expert opinion and research evidence.
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