Examining functional group-dependent effects on the ionization of lignin monomers using supercritical fluid chromatography/electrospray ionization mass spectrometry.

The chemical and biological conversion of biomass-derived lignin is a promising pathway for producing valuable low molecular weight aromatic chemicals, such as vanillin or guaiacol, known as lignin monomers (LMs). Various methods employing chromatography and electrospray ionization-mass spectrometry (ESI-MS) have been developed for LM analysis, but the impact of LM chemical properties on analytical performance remains unclear. This study systematically optimized ESI efficiency for 24 selected LMs, categorized by functionality. Fractional factorial designs were employed for each LM to assess ESI parameter effects on ionization efficiency using ultra-high-performance supercritical fluid chromatography/ESI-MS (UHPSFC/ESI-MS). Molecular descriptors were also investigated to explain variations in ESI parameter responses and chromatographic retention among the LMs. Structural differences among LMs led to complex optimal ESI settings. Notably, LMs with two methoxy groups benefited from higher gas and sheath gas temperatures, likely due to their lower log P and higher desolvation energy requirements. Similarly, vinyl acids and ketones showed advantages at elevated gas temperatures. The retention in UHPSFC using a diol stationary phase was correlated with the number of hydrogen bond donors. In summary, this study elucidates structural features influencing chromatographic retention and ESI efficiency in LMs. The findings can aid in developing analytical methods for specific technical lignins. However, the absence of an adequate number of LM standards limits the prediction of LM structures solely based on ESI performance data.

Thermodynamic Assessment of Triclocarban Dissolution Process in N-Methyl-2-pyrrolidone + Water Cosolvent Mixtures.

Solubility is one of the most important physicochemical properties due to its involvement in physiological (bioavailability), industrial (design) and environmental (biotoxicity) processes, and in this regard, cosolvency is one of the best strategies to increase the solubility of poorly soluble drugs in aqueous systems. Thus, the aim of this research is to thermodynamically evaluate the dissolution process of triclocarban (TCC) in cosolvent mixtures of {N-methyl-2-pyrrolidone (NMP) + water (W)} at seven temperatures (288.15, 293.15, 298.15, 303.15, 308.15, 313.15 and 318.15 K). Solubility is determined by UV/vis spectrophotometry using the flask-shaking method. The dissolution process of the TCC is endothermic and strongly dependent on the cosolvent composition, achieving the minimum solubility in pure water and the maximum solubility in NMP. The activity coefficient decreases from pure water to NMP, reaching values less than one, demonstrating the excellent positive cosolvent effect of NMP, which is corroborated by the negative values of the Gibbs energy of transfer. In general terms, the dissolution process is endothermic, and the increase in TCC solubility may be due to the affinity of TCC with NMP, in addition to the water de-structuring capacity of NMP generating a higher number of free water molecules.

Imaging Aspects of the Hippocampus.

The hippocampus is one of the most sophisticated structures in the brain, owing to its complex anatomy, intriguing functions, relationship with other structures, and relevant associated symptoms. Despite being a structure analyzed for centuries, its anatomy and physiology in the human body are still being extensively studied, as well as associated pathologic conditions and potential biomarkers. It can be affected by a broad group of diseases that can be classified as congenital, degenerative, infectious or inflammatory, neoplastic, vascular, or toxic-metabolic disease. The authors present the anatomy and close structures, function, and development of the hippocampus, as well as an original algorithm for imaging diagnosis. The algorithm includes pathologic conditions that typically affect the hippocampus and groups them into nodular (space occupying) and nonnodular pathologic conditions, serving as a guide to narrow the differential diagnosis. MRI is the imaging modality of choice for evaluation of the hippocampus, and CT and nuclear medicine also improve the analysis. The MRI differential diagnosis depends on anatomic recognition and careful characterization of associated imaging findings such as volumetric changes, diffusion restriction, cystic appearance, hyperintensity at T1-weighted imaging, enhancement, or calcification, which play a central role in diagnosis along with clinical findings. Some pathologic conditions arising from surrounding structures such as the amygdala are also important to recognize. Pathologic conditions of the hippocampus can be a challenge to diagnose because they usually manifest as similar clinical syndromes, so the imaging findings play a potential role in guiding the final diagnosis. Online supplemental material is available for this article. ©RSNA, 2022.

Thermodynamic Analysis of the Solubility of Isoniazid in (PEG 200 + Water) Cosolvent Mixtures from 278.15 K to 318.15 K.

The solubility of drugs in cosolvent systems of pharmaceutical interest is of great importance for understanding and optimizing a large number of processes. Here, we report the solubility of isoniazid in nine (PEG 200 + water) cosolvent mixtures at nine temperatures (278.15, 283.15, 288.15, 293.15, 298.15, 303.15, 308.15, and 318.15 K) determined by UV-vis spectrophotometry. From the solubility data, the thermodynamic solution, mixing, and transfer functions were calculated in addition to performing the enthalpy-entropy compensation analysis. The solubility of isoniazid depends on the concentration of PEG 200 (positive cosolvent effect) and temperature (endothermic process) reaching its maximum solubility in pure PEG 200 at 318.15 K and the lowest solubility in pure water at 278.15 K. The solution process is favored by the solution entropy and according to the enthalpy-entropy compensation analysis it is driven by entropy in mixtures rich in water and by enthalpy in mixtures rich in PEG 200.

Point-of-care lung ultrasound assessment for risk stratification and therapy guiding in COVID-19 patients: a prospective noninterventional study.

BACKGROUND: Lung ultrasound is feasible for assessing lung injury caused by coronavirus disease 2019 (COVID-19). However, the prognostic meaning and time-line changes of lung injury assessed by lung ultrasound in COVID-19 hospitalised patients are unknown. METHODS: Prospective cohort study designed to analyse prognostic value of lung ultrasound in COVID-19 patients by using a quantitative scale (lung ultrasound Zaragoza (LUZ)-score) during the first 72 h after admission. The primary end-point was in-hospital death and/or admission to the intensive care unit. Total length of hospital stay, increase of oxygen flow and escalation of medical treatment during the first 72 h were secondary end-points. RESULTS: 130 patients were included in the final analysis; mean±sd age was 56.7±13.5 years. Median (interquartile range) time from the beginning of symptoms to admission was 6 (4-9) days. Lung injury assessed by LUZ-score did not differ during the first 72 h (21 (16-26) points at admission versus 20 (16-27) points at 72 h; p=0.183). In univariable logistic regression analysis, estimated arterial oxygen tension/inspiratory oxygen fraction ratio (PAFI) (hazard ratio 0.99, 95% CI 0.98-0.99; p=0.027) and LUZ-score >22 points (5.45, 1.42-20.90; p=0.013) were predictors for the primary end-point. CONCLUSIONS: LUZ-score is an easy, simple and fast point-of-care ultrasound tool to identify patients with severe lung injury due to COVID-19, upon admission. Baseline score is predictive of severity along the whole period of hospitalisation. The score facilitates early implementation or intensification of treatment for COVID-19 infection. LUZ-score may be combined with clinical variables (as estimated by PAFI) to further refine risk stratification.

Photonic lantern tip/tilt detector for adaptive optics systems.

In this work, we demonstrate a four-core multicore fiber photonic lantern tip/tilt wavefront sensor. To diagnose the low-order Zernike aberrations, we exploit the ability of the photonic lantern to encode the characteristics of a complex incoming beam at the multimode facet of the sensor to intensity distributions at the multicore fiber output. Here, we provide a comprehensive numerical analysis capable of predicting the performance of fabricated devices and experimentally demonstrate the concept. Two receiver architectures are implemented to discern tip/tilt information by (i) imaging the four-core fiber facet on a 2D detector and (ii) direct power measurement of the single mode outputs using a multicore fiber multiplexer and photodetectors. For both receiver schemes, an angular detection window of ∼0.4∘ at 1064 nm can be achieved. Our results are expected to further facilitate the development of intensity-based fiber wavefront sensors for adaptive optics systems.

Solubility of Sulfamethazine in the Binary Mixture of Acetonitrile + Methanol from 278.15 to 318.15 K: Measurement, Dissolution Thermodynamics, Preferential Solvation, and Correlation.

Solubility of sulfamethazine (SMT) in acetonitrile (MeCN) + methanol (MeOH) cosolvents was determined at nine temperatures between 278.15 and 318.15 K. From the solubility data expressed in molar fraction, the thermodynamic functions of solution, transfer and mixing were calculated using the Gibbs and van 't Hoff equations; on the other hand, the solubility data were modeled according to the Wilson models and NRTL. The solubility of SMT is thermo-dependent and is influenced by the solubility parameter of the cosolvent mixtures. In this case, the maximum solubility was achieved in the cosolvent mixture w0.40 at 318.15 K and the minimum in pure MeOH at 278.15 K. According to the thermodynamic functions, the SMT solution process is endothermic in addition to being favored by the entropic factor, and as for the preferential solvation parameter, SMT tends to be preferentially solvated by MeOH in all cosolvent systems; however, δx3,1<0.01, so the results are not conclusive. Finally, according to mean relative deviations (MRD%), the two models could be very useful tools for calculating the solubility of SMT in cosolvent mixtures and temperatures different from those reported in this research.

Enhanced NiO Dispersion on a High Surface Area Pillared Heterostructure Covered by Niobium Leads to Optimal Behaviour in the Oxidative Dehydrogenation of Ethane.

A Nb-containing siliceous porous clay heterostructure (PCH) with Nb contents from 0 to 30 wt %) was prepared from a bentonite and used as support in the preparation of supported NiO catalysts with NiO loading from 15 to 80 wt %. Supports and NiO-containing catalysts were characterised by several physicochemical techniques and tested in the oxidative dehydrogenation (ODH) of ethane. The characterisation studies on Nb-containing supports showed the presence of well-anchored Nb5+ species without the formation of Nb2 O5 crystals. High dispersion of nickel oxide with low crystallinity was observed for the Nb-containing PCH supports. In addition, when NiO is supported on these Nb-containing porous clays, it is more effective in the ODH of ethane (ethylene selectivity of ca. 90 %) than NiO supported on the corresponding Nb-free siliceous PCH or on Nb2 O5 (ethylene selectivities of ca. 30 and 60 %, respectively). Factors such as the NiO-Nb5+ interaction, the NiO particle size and the properties of surface Nin+ species were shown to determine the catalytic performance.

Safety and Efficacy of the Tracheobronchial Bonastent: A Single-Center Case Series.

BACKGROUND: Tracheobronchial stents are widely used devices in interventional pulmonology; however, the current literature on the effectiveness and complication rates of the different types of stents is limited. OBJECTIVE: We report the largest case series of airway Bonastent placement and describe the efficacy and early (<30 days) and late (≥30 days) complication rates. METHODS: We performed a retrospective review of our prospectively collected database of patients who underwent therapeutic bronchoscopy with stent placement. All adult patients who had a tracheal/bronchial Bona-stent placed between July 1, 2017, and July 30, 2019, for any indication at our institution were included. The efficacy as well as intraoperative and short- and long-term complications of Bonastent placement were evaluated. RESULTS: Sixty Bonastents were placed in 50 patients. The etiology was malignant in 90% of the cases, while 2 patients had a tracheoesophageal fistula. All procedures were performed via rigid bronchoscopy. The most common location for stent placement was the bronchus intermedius, followed by the trachea, in 32 and 30% of the cases, respectively. Seventy percent of the patients (35/50) had improvement of respiratory symptoms within 30 days. Twenty-eight stents (48%) were removed at a mean of 74 days. Seventeen patients (34%) died within 30 days of stent placement. The overall complication rate was 54% (27/50 patients) at a mean follow-up of 111 days. The stent-related complication rate was 23.3% (14/60 cases) within <30 days and 53% (18/34 cases) at ≥30 days. CONCLUSIONS: The tracheobronchial Bonastent is effective for the treatment of patients with central airway obstruction and tracheoesophageal fistulae with an acceptable safety profile.

Nanosized titanium dioxide UV filter increases mixture toxicity when combined with parabens.

To address the concern about the environmental impact of engineered nanoparticles frequently used in the recently marketed personal care and hygiene products (PCPs), we conducted a toxicity assessment and determined the EC50 values of the nanosized inorganic UV filter TiO2 (nano-TiO2), as well as those of the organic UV filter oxybenzone (BP3) and three parabens (methyl, propyl, and benzylparaben) present in most PCPs formulation. The bioassays were carried out through standardized toxicity bioassays on two environmentally relevant aquatic species i.e. Daphnia magna and Phaeodactylum tricornutum. For nano-TiO2 48 h EC50 on D. magna was 3.09 mgL-1 and for parabens ranged from 32.52 to 1.35 mgL-1. The two most toxic compounds on D. magna, nano-TiO2 and benzylparaben (BzP), were further tested with the algae. For nano-TiO2 72 h EC50 value was 2.27 mgL-1 and for BzP it was 10.61 mgL-1. In addition, D. magna was exposed to selected binary mixtures of the target compounds i.e. nano-TiO2+BP3, nano-TiO2+BzP and BP3+BzP On the endpoint of 48 h, a synergistic action was observed for nano-TiO2+BP3 and nano-TiO2+BzP, but an antagonistic effect occurred in the mixture BP3+BzP. These findings suggest that nano-TiO2 can increase the toxicity of the mixture when combined with other compounds.

Determination of UV filters in human breast milk using turbulent flow chromatography and babies' daily intake estimation.

UV filters (UV-Fs) are a group of hormonally active chemical compounds used to protect against the deleterious effects of UVA and UVB solar radiation, which are currently present in most consumer goods (personal care products, plastics, fabrics, paints, etc). Last years the concern about these emerging contaminants has been on the rise, and increasing efforts are being taken in order to properly asses the hazard that the exposure to these compounds in the early stages of life may pose. In this study, a new method for the analysis of 11 UV-Fs residues in human breast milk samples has been developed. The method is based on turbulent flow chromatography coupled to liquid chromatography-tandem mass spectrometry (TFC-HPLC-MS/MS). The validated method was successfully applied to 79 human breast milk samples from mothers in Barcelona (Spain). Twenty-four per cent of the samples contained UV-Fs, with major contributors being oxybenzone (benzophenone 3, BP3), its metabolite 4,4'-dihydroxybenzophenone (4DHB), and UV320 showing maximum concentrations of 779.9, 73.3, and 523.6ngg-1 milk, respectively. Additionally, the plastic containers of the milks were also analysed, revealing high concentrations of BP3 and 4DHB, up to 10.6µgg-1 plastic. The calculated mean ΣUV-Fs were useful to estimate the daily intake (EDI) by babies, which were 69.1µg d-1kg-1 body weight.

A Potential New Threat to Wild Life: Presence of UV Filters in Bird Eggs from a Preserved Area.

The present study uses bird eggs of seven wild species as a biomonitoring tool for sunscreens occurrence. Seven UV filters (UV-Fs), including 3 hydroxy-metabolites of oxybenzone (benzophenone 3, BP3) were characterized in unhatched eggs from Doñana Natural Space (Spain). High frequency of detection was observed for all UV-Fs, ranging from 95% to 100%. The oxybenzone metabolite 4-hydroxybenzophenone (4HB) was ubiquitous at concentrations in the range 12.0-3348 ng g-1 dry weight (dw). The parent compound, oxybenzone, was also present in all samples at lower concentrations (16.9-49.3 ng g-1 dw). Due to the three BP3's metabolites, benzophenone 1 (BP1), 4HB, and 4,4'-dihydroxybenzophenone (4DHB) presence in unhatched eggs, it can be inferred that parent compounds are absorbed into the bird through the upper gut and the OH-derivatives formed are transferred by the mother to the egg before the lying. White stork (Ciconia ciconia) and western marsh harrier (Circus aeruginosus) were the most contaminated species, with mean total UV-Fs concentrations of 834 and 985 ng g-1 dw, respectively. Results evidenced that biomagnification process across the bird species studied cannot be ruled out.

Single and joint ecotoxicity data estimation of organic UV filters and nanomaterials toward selected aquatic organisms. Urban groundwater risk assessment.

The hazardous potential of organic UV filters (UV-Fs) is becoming an issue of great concern due to the widespread application of these compounds in most daily-use goods, such as hygiene and beauty products. Nanomaterials (NMs) have also been used in personal care products (PCPs) for many years. Nowadays, both classes of chemicals are considered environmental emerging contaminants. Despite some studies performed in vitro and in vivo reported adverse effects of many UV-Fs on the normal development of organisms, there is scarce data regarding acute and chronic toxicity. The aim of the present study was to determine the EC50 values of selected UV-Fs using standardised toxicity assays on three aquatic species i.e. Daphnia magna, Raphidocelis subcapitata and Vibrio fischeri. EC50 values obtained were in the mgl(-1) range for all the species. The estimated toxicity data allowed us to assess the environmental risk posed by selected UV-Fs in urban groundwater from Barcelona (Spain). The calculated ecological risk indicated a negligible impact on the aquifer. Giving the increasing importance of studying mixtures of pollutants and due to the widespread presence of nanomaterials (NMs) in the aquatic environment, other objective of this work was to explore the response on D. magna after exposure to both binary combinations of UV-Fs among them and UV-F with NMs. In all cases but the nano-silver mixtures, joint toxicity was mitigated or even eradicated.

Deconvolution of fluorescence lifetime imaging microscopy by a library of exponentials.

Fluorescence lifetime microscopy imaging (FLIM) is an optic technique that allows a quantitative characterization of the fluorescent components of a sample. However, for an accurate interpretation of FLIM, an initial processing step is required to deconvolve the instrument response of the system from the measured fluorescence decays. In this paper, we present a novel strategy for the deconvolution of FLIM data based on a library of exponentials. Our approach searches for the scaling coefficients of the library by non-negative least squares approximations plus Thikonov/l(2) or l(1) regularization terms. The parameters of the library are given by the lower and upper bounds in the characteristic lifetimes of the exponential functions and the size of the library, where we observe that this last variable is not a limiting factor in the resulting fitting accuracy. We compare our proposal to nonlinear least squares and global non-linear least squares estimations with a multi-exponential model, and also to constrained Laguerre-base expansions, where we visualize an advantage of our proposal based on Thikonov/l(2) regularization in terms of estimation accuracy, computational time, and tuning strategy. Our validation strategy considers synthetic datasets subject to both shot and Gaussian noise and samples with different lifetime maps, and experimental FLIM data of ex-vivo atherosclerotic plaques and human breast cancer cells.

Estimation of the number of fluorescent end-members for quantitative analysis of multispectral FLIM data.

Multispectral fluorescence lifetime imaging (m-FLIM) can potentially allow identifying the endogenous fluorophores present in biological tissue. Quantitative description of such data requires estimating the number of components in the sample, their characteristic fluorescent decays, and their relative contributions or abundances. Unfortunately, this inverse problem usually requires prior knowledge about the data, which is seldom available in biomedical applications. This work presents a new methodology to estimate the number of potential endogenous fluorophores present in biological tissue samples from time-domain m-FLIM data. Furthermore, a completely blind linear unmixing algorithm is proposed. The method was validated using both synthetic and experimental m-FLIM data. The experimental m-FLIM data include in-vivo measurements from healthy and cancerous hamster cheek-pouch epithelial tissue, and ex-vivo measurements from human coronary atherosclerotic plaques. The analysis of m-FLIM data from in-vivo hamster oral mucosa identified healthy from precancerous lesions, based on the relative concentration of their characteristic fluorophores. The algorithm also provided a better description of atherosclerotic plaques in term of their endogenous fluorophores. These results demonstrate the potential of this methodology to provide quantitative description of tissue biochemical composition.

Configurable spatiotemporal properties in a photon-pair source based on spontaneous four-wave mixing with multiple transverse modes.

We present an experimental and theoretical study of photon pairs generated by spontaneous four-wave mixing (SFWM), based on birefringent phasematching, in a fiber that supports more than one transverse mode. We present SFWM spectra, obtained through single-channel and coincidence photon counting, which exhibit multiple peaks shown here to be the result of multiple SFWM processes associated with different combinations of transverse modes for the pump, signal, and idler waves.

Network efficient power control for wireless communication systems.

We introduce a two-loop power control that allows an efficient use of the overall power resources for commercial wireless networks based on cross-layer optimization. This approach maximizes the network's utility in the outer-loop as a function of the averaged signal to interference-plus-noise ratio (SINR) by considering adaptively the changes in the network characteristics. For this purpose, the concavity property of the utility function was verified with respect to the SINR, and an iterative search was proposed with guaranteed convergence. In addition, the outer-loop is in charge of selecting the detector that minimizes the overall power consumption (transmission and detection). Next the inner-loop implements a feedback power control in order to achieve the optimal SINR in the transmissions despite channel variations and roundtrip delays. In our proposal, the utility maximization process and detector selection and feedback power control are decoupled problems, and as a result, these strategies are implemented at two different time scales in the two-loop framework. Simulation results show that substantial utility gains may be achieved by improving the power management in the wireless network.

Which intranasal corticosteroids can be used in patients on highly active antiretroviral therapy or pre-exposure prophylactic?

KEY POINTS: All intranasal corticosteroid spray formulations are safe to use in patients on pre-exposure prophylaxis. Beclomethasone nasal spray can be used safely with all HAART and PrEP regimens.

"Left on their own": Left-handedness among rhinologists and otolaryngology trainees.

KEY POINTS: Left-hand-dominant (LHD) respondents reported higher rates of training difficulties because of handedness differences. LHD respondents cited particular difficulty with functional endoscopic sinus surgery. Both LHD and right-hand-dominant respondents perceived a need for laterality-specific training during residency.

Preoperative Workup of Patients With Excessive Central Airway Collapse: Does Stent Evaluation Serve a Role?

BACKGROUND: Tracheobronchoplasty (TBP) is a definitive anatomic intervention for patients with severe symptomatic expiratory central airway collapse. Although stent evaluations have been described for surgical workup, current literature does not address if improvement during stent evaluation is sustained after TBP. We compared health-related quality of life (HRQOL) and functional status responses after airway stenting to those post-TBP. METHODS: A retrospective review was performed in patients with severe expiratory central airway collapse who underwent stent evaluation followed by TBP from January 2004 to December 2019. Baseline, poststent, 3- and 12-month postoperative HRQOL scores, and functional status were analyzed with statistical tests as appropriate. RESULTS: One hundred twenty patients underwent a stent evaluation and TBP. Baseline and stent evaluation measurements were compared with statistically and clinically significant differences in the Cough Quality-of-life Questionnaire (CQLQ) (55 vs. 68, P <0.01), Modified Medical Research Council (mMRC) 0 to 2 (90% vs. 47%, P <0.01), 6-minute walk test (6MWT) (1301 ft vs. 1138 ft, P <0.01). Improvements in the HRQOL and functional status were maintained from stent evaluation to 3 months postoperatively [CQLQ 55 vs. 54, P =0.63; mMRC 0 to 2 (87% vs. 84%), P =0.39; 6MWT 1350 ft vs. 1314 ft, P =0.33], and 12 months postoperatively [CQLQ 54 vs. 54, P =0.91; mMRC 0 to 2 (95% vs. 86%), P =0.74; 6MWT 1409 ft vs. 1328 ft, P =0.13]. The magnitude of change between the data was not significantly different between the stent evaluation, 3-, and 12 months postoperative. Predicted forced expiratory volume in 1-second measurements at baseline, after stent placement, 3 months, and 12 months post-TBP were 74%, 79%, 73%, and 73%, respectively, and not clinically significant. CONCLUSIONS: Improvement after stent evaluation and the magnitude of improvement may be predictive of postoperative outcomes up to 1 year after surgery.