Assessment and Treatment Strategies for the Aesthetic Improvement of the Lower Face and Neck.

Background: Interest in aesthetic rejuvenation of the lower face and neck is growing, but published expert guidance is limited. Objective: Review aesthetic concerns of the lower face and neck and provide expert guidance on evaluation and treatment. Methods: Twelve international experts participated in an advisory board on lower face and neck aesthetic treatment. They completed a premeeting survey and met twice, reviewing responses and discussing patient evaluation and treatment strategies. They developed decision tree algorithms on patient assessment and treatment planning and sequencing, using clinical cases as a reference. Results: Treatment concerns include neck and lower face skin laxity, structural bone deficiency, insufficient or excess volume, submental fat, jowls, platysma bands, and masseter muscle prominence. Advisors agreed that the lower face and neck may be the most challenging areas to assess and treat; treatment goals include lower facial contour and overall facial harmony/balance. Advisors recommended first ruling out a surgical approach, then determining whether midface treatment is needed to support the lower face, and lastly evaluating the lower face for significant submental fat, excess or insufficient volume, and structural bone deficiency. To treat the lower face and neck, an anatomical layer approach, moving from deep to superficial layers, beginning with structural support, was recommended. Assessment and treatment decision trees were based on this approach. Conclusion: The lower face and neck are important but underrecognized areas of aesthetic concern. This article provides expert guidance and a suggested algorithm for assessment and treatment aimed at achieving satisfying and harmonious facial aesthetic results.

Associations between chronotype, sleep quality, maternal mental health, and child development in mother-infant dyads.

OBJECTIVE/BACKGROUND: Studies on circadian rhythms throughout development and their physiological and behavioral impacts at early stages are still scarce. Previous studies have shown that mother-infant interactions are important for both sleep and child development. In this cross-sectional study we investigated whether infants' chronotype, sleep and development were associated with their respective mothers' chronotype, sleep, mental health and socioeconomic status. PATIENTS/METHODS: the following were used to evaluate mothers: the Morningness-Eveningness Questionnaire (MEQ), Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS) and Self-Reporting Questionnaire 20 (SRQ-20). To assess the infants' characteristics, the following were used: the 19th question from the Morningness-Eveningness Questionnaire (MEQ), infant nocturnal midpoint of sleep (iMSF), Brief Infant Sleep Questionnaire (BISQ) and Ages and Stages Questionnaire-3 (ASQ3). Socioeconomic aspects were assessed using the Brazilian Economic Class Criterion of the Brazilian Association of Research Companies (ABEP). RESULTS: A hundred and eight mother-infant dyads participated in the study. Sleep disorders were observed in 38 (35%) infants and atypical development (ASQ3) in 35 (32%). The infants' sleep phases were partially explained by the mother's chronotype. Infants' sleep duration was negatively correlated with sleep latency, which was higher in the group with atypical development. Mothers of infants with sleep disorders or discordant chronotypes (32%) had higher Pittsburgh scores (worse sleep quality) and higher SRQ-20 scores (screen for Common Mental Disorders). CONCLUSIONS: We found evidence for the contribution of sleep quality and chronotypes to mothers' mental health and infant development. However, further studies are needed to confirm the influence of sleep and circadian phenotypes in the early stages.

Myomodulation with Facial Fillers: A Comprehensive Technical Guide and Retrospective Case Series.

BACKGROUND: Placement of fillers in close proximity to the mimetic or sphincter muscles of the face appears to enhance or suppress muscle action in a relatively predictable way. METHODS: From June 2016 to June 2021, patients who underwent the first author's technique of myomodulation with dermal fillers to address aesthetic concerns or to manage facial spasms or synkinesis were evaluated in a retrospective case series. Additionally, the authors provide a technical guide for a whole-face approach to treatment with fillers and a conceptual map for treatment of each facial subunit with a focus on myomodulation. RESULTS: A total of 1352 patients (1108 women, 244 men; mean age, 51 years) underwent at least 1 treatment session during the 5-year study period. The treatment patterns of the study population and details of 2 representative cases are presented. CONCLUSIONS: Although not well understood mechanistically, myomodulation with injectable fillers shows promise for significant and reliable results of facial rejuvenation. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Clinical experience with a new injectable hyaluronic acid designed to improve skin quality in a private clinic in Brazil: A retrospective cohort study.

BACKGROUND: Juvéderm Volite is a skin-conditioning hyaluronic acid (HA) gel for intradermal injection that provides longer-lasting effects with a lower concentration of hyaluronic acid. Few studies evaluating its use for aesthetic purposes are available. AIM: To examine the use and safety of Juvéderm Volite in daily clinical practice. METHODS: A retrospective cohort study of subjects treated with Juvéderm Volite for aesthetic purposes from May 2018 to October 2019 in Rio de Janeiro. Data were extracted from the attending physician's records obtained at each medical appointment. Subjects were assessed according to their age group and treatment characteristics, which include the use of cannulas vs needles and the effectiveness and safety of associated treatments in a single session. Need for subsequent treatment was stratified by touch-up treatment (<3-month period) and repeat treatment (≥3-month period). Safety assessment was based on the report of nodule formation and late hypersensitivity in patients. Appropriate statistical tests were used for data analysis. RESULTS: One hundred and eight subjects were included in the study analysis. The total number of treatment sessions consisted of 159, with a mean follow-up time of 300.3 days. Of the total 108 subjects, 8.4% required touch-up treatment for optimum correction and repeat treatment occurred in 9.0%. No cases of adverse events were reported during the follow-up period. CONCLUSIONS: This study has shown, based on clinical observation, that Juvéderm Volite is a useful tool to improve skin quality, requiring fewer and less frequent maintenance treatments. No serious adverse events were reported during the follow-up period.

The Influence of Different Light Angles During Standardized Patient Photographic Assessment on the Aesthetic Perception of the Face.

BACKGROUND: 2D baseline and follow-up clinical images are potentially subject to inconsistency due to alteration of imaging parameters. However, no study to date has attempted to quantify the magnitude by which such images can be influenced. OBJECTIVE: The objective of the present study is to identify the magnitude by which images can be influenced by changing the imaging light angle. METHODS: This study is based on the evaluation of 2D frontal images of the face and included a total of 51 subjects of which n = 14 were males and n = 37 were females. Faces were photographed at 0°, 30°, and 60° light angle under identical and standardized conditions. Images were randomized and rated by 27 blinded raters for age, facial attractiveness, body mass index (BMI), temporal hollowing, lower cheek fullness, nasolabial sulcus severity, and jawline contour. RESULTS: Facial attractiveness decreased, facial unattractiveness increased and the evaluated BMI (based on facial assessment) increased statistically significantly at 60°. The assessment of regional facial scores, i.e., temporal hollowing, lower cheek fullness, and jawline contour, showed no statistically meaningful changes both at 30° and at 60° light angle. CONCLUSION: The results indicate that there might be an observed blind range in light angle (0°-30°) which does not influence facial assessment. Increasing the light angle past the threshold value to 60° might result in a statistically significant impact on facial perception which should be accounted for when documenting and/or presenting facial 2D images. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Are DFT Methods Able to Predict Reduction Potentials of Ruthenium Nitrosyl Complexes Accurately?

The nitric oxide (NO) molecule is directly related to important physiological and physiopathological processes. Ruthenium tetraammine nitrosyl complexes can release NO from the [RuIINO+]3+/[RuIINO0]2+ reduction potential. Experimentally, well established is the practice of determining the redox potential with relation to a reference redox pair. However, there is no agreement on the best methodology that allows the minimization of uncertainties, both experimental and theoretical results. Here, the reduction potential relative to a reference redox pair is obtained from calculated absolute potentials for the target complex: trans-[Ru(NO)(L)(NH3)4]3+/2+ and reference pair: [Ru(bpy)3]3+/2+. The correlation between the calculated and experimental reduction potentials strongly depend on the DFT functional chosen. The best results were obtained with the GGA functional BP86, which showed deviations lower than 200 mV. The assignment of explicit solvent, in addition to continuum solvent influence, also appears as a relevant factor.

Environmental temperature as a mediator on the association between photoperiod at birth and chronotype.

The association between chronotypes and season of birth (SOB) remains an inconclusive issue due, in some extension, to the lack of investigations of mediation mechanisms. We evaluated the association of photoperiod at birth (PAB) with chronotypes and sleep duration in Brazil (n = 810), and the mediating effect of meteorological factors, sex, age and rs4753426 polymorphism in the melatonin receptor MTNR1B. Longer PAB was associated with a delayed mid-sleep phase with a suppressive effect of maximum environmental temperature. No significant interactions were identified for the other variables. These findings suggest that photoperiod and environmental temperature modulate chronotype development at early stages.

The six different injection techniques for the temple relevant for soft tissue filler augmentation procedures - Clinical anatomy and danger zones.

OBJECTIVE: The most promising facial region for inducing pan-facial effects is the temporal region. The temple displays signs of facial aging itself which include temporal volume loss and increased visibility of the temporal crest, the temporal vasculature, the lateral orbital rim, and the upper zygomatic arch. The objective of this article is to provide a detailed review of temple anatomy pertaining to routinely performed temporal injection techniques, their expected esthetic outcomes as well as the intendant advantages, disadvantages, and procedure pearls. MATERIALS AND METHODS: This narrative review is based on the clinical experience of the authors treating the temporal region for esthetic purposes. The postulated outcome of each technique was observed during the routine clinical practice of the authors. RESULTS: The temporal region is based on a bony platform consisting of the parietal, frontal, sphenoid, and temporal bones. The overlying soft tissues are arranged in layers which contain the temporal neurovascular structures. The temporal soft tissues consist of 10 parallel layers which vary in their thickness depending on age-related influences. Six different techniques will be addressed, which include subdermal and interfascial techniques for volumizing, low and high supraperiosteal techniques for volumizing, and supraauricular and temporal lifting techniques. CONCLUSION: This narrative provides a detailed anatomic overview of the temporal region and describes each commonly performed injection technique with respect to anatomy, esthetic outcome, as well as potential pearls and pitfalls. It is hoped that the description contained herein may guide esthetic practitioners toward safer and more natural outcomes when treating the face.

Recommendations on the Use of Injectable Poly-L-Lactic Acid for Skin Laxity in Off-Face Areas

Injectable poly-L-lactic acid (PLLA) is a biodegradable synthetic polymer that stimulates collagen production, leading to gradual volume restoration. The treatment of sagging skin in body areas is still a big challenge, as there are few aesthetic procedures aiming to improve it. This article provides recommendations on the use of PLLA in the treatment of skin laxity in off-face areas, as the neck, décolletage, arms, abdomen, buttocks, and thighs, including the patient selection, product preparation, and injection techniques. The use of PLLA is a promising method for the treatment of skin laxity in corporal areas, improving body contour and appearance. Further investigation is needed to better understand the efficacy and durability of PLLA in non-facial indications and to provide the best evidence for optimal patient outcomes. J Drugs Dermatol. 2019;18(9):929-935.

Synthesis, characterization and biological evaluation of new manganese metal carbonyl compounds that contain sulfur and selenium ligands as a promising new class of CORMs.

Three new manganese carbonyl compounds with heavy atom donors were synthesized and their potential use as photoCORMS was evaluated. Interestingly, all compounds had an elusive binding mode, in which the ligands adopted a κ2-X coordination (where X = S or Se), confirmed both by X-ray crystallography and IR spectroscopy. The stability of the title compounds in the dark was determined by monitoring the changes in the UV spectra of the compounds in both dichloromethane and acetonitrile. These studies show that in coordinating solvents there is an exchange of the bromide bonded to the metal centre by a solvent molecule, which is evidenced by the changes in the UV and IR spectra and by DFT analysis. EDA and natural bond order analyses were conducted to evaluate the influence of the heavy atom donors in the first coordination sphere of the compounds. Photoexcitation at 380 nm demonstrated that all compounds showed release of all three COs, as seen in the photoproducts detected by IR spectroscopy. Furthermore, CO release was observed when the photoCORMs were incubated with living cells, and we observed a CO-dependent inhibition of cell viability.

Usual normalization strategies for gene expression studies impair the detection and analysis of circadian patterns.

Recent studies have shown that transcriptomes from different tissues present circadian oscillations. Therefore, the endogenous variation of total RNA should be considered as a potential bias in circadian studies of gene expression. However, normalization strategies generally include the equalization of total RNA concentration between samples prior to cDNA synthesis. Moreover, endogenous housekeeping genes (HKGs) frequently used for data normalization may exhibit circadian variation and distort experimental results if not detected or considered. In this study, we controlled experimental conditions from the amount of initial brain tissue samples through extraction steps, cDNA synthesis, and quantitative real time PCR (qPCR) to demonstrate a circadian oscillation of total RNA concentration. We also identified that the normalization of the RNA's yield affected the rhythmic profiles of different genes, including Per1-2 and Bmal1. Five widely used HKGs (Actb, Eif2a, Gapdh, Hprt1, and B2m) also presented rhythmic variations not detected by geNorm algorithm. In addition, the analysis of exogenous microRNAs (Cel-miR-54 and Cel-miR-39) spiked during RNA extraction suggests that the yield was affected by total RNA concentration, which may impact circadian studies of small RNAs. The results indicate that the approach of tissue normalization without total RNA equalization prior to cDNA synthesis can avoid bias from endogenous broad variations in transcript levels. Also, the circadian analysis of 2-Cycle threshold (Ct) data, without HKGs, may be an alternative for chronobiological studies under controlled experimental conditions.

Diagnóstico e tratamento dos eventos adversos do ácido hialurônico: recomendações de consenso do painel de especialistas da América Latina / Diagnosis and treatment of hyaluronic acid adverse events: Latin American expert panel consensus recommendations

Introdução: Na última década, o uso do preenchimento com ácido hialurônico para aprimoramento facial aumentou na América Latina. O preenchimento com ácido hialurônico é considerado seguro com baixa incidência de eventos adversos. Como eventos adversos são pouco observados na prática clínica ou têm sido possivelmente sub-relatados são necessárias mais orientações para diagnosticar e tratar eventos adversos relacionados ao ácido hialurônico. Objetivo: Compreender melhor os eventos adversos relacionados ao ácido hialurônico e propor recomendações para o diagnóstico e tratamento. Métodos: Reunião em painel de 25 especialistas médicos multidisciplinares da América Latina foi realizada em São Paulo, Brasil, para discutir o que se conhece sobre eventos adversos relacionados ao ácido hialurônico e fornecer conhecimentos baseados na experiência clínica. Por meio de consenso, foram desenvolvidos recomendações e algoritmos. Resultados: O painel categorizou eventos adversos relacionados ao ácido hialurônico baseado em três momentos de início (imediato, precoce e tardio) e propôs um novo termo para eventos adversos que apresentam edema tardio intermitente persistente ("Etip"). Foram criados algoritmos para diagnóstico e tratamento em cada momento. Conclusões: Novos algoritmos consensuais para diagnósticos e tratamentos associados ao momento de início dos eventos adversos relacionados ao ácido hialurônico orientarão melhores práticas no uso clínico do preenchimento com ácido hialurônico.

Introduction: In the last decade, the use of hyaluronic acid fillers for facial enhancement has increased in Latin America. Hyaluronic acid fillers are considered relatively safe with a low incidence of adverse events. Because adverse events are not seen frequently in clinical practice or have been potentially underreported, there is a need for more guidance on the diagnosis and treatment of Hyaluronic acid-related adverse events. Objecti ve: To provide an enhanced understanding of hyaluronic acid-related adverse events and to propose recommendations for their diagnosis and treatment. Methods: A 25-member multi-disciplinary expert panel meeting of Latin-American physicians was convened in Sao Paulo, Brazil to discuss what is known about hyaluronic acid-related adverse events and to provide insights based on clinical experience. Recommendations and algorithms were developed through a consensus process. Results: The panel categorized hyaluronic acid-related adverse events based on 3 time frames of onset (immediate, early and Late) and proposed a new term for adverse events that display persistent, intermittent, delayed Swelling (PIDS). Algorithms were created for diagnosis and treatment for each time frame. Conc lusions: The new consensus algorithms for time-related diagnosis and treatment of hyaluronic acid-related adverse events will provide guidance for best practices in the clinical use of hyaluronic acid fillers.

Association of BDNF Val66MET Polymorphism With Parkinson's Disease and Depression and Anxiety Symptoms.

An association between Parkinson's disease (PD) and brain-derived neurotrophic factor (BDNF) was suggested by several studies, with contradictory results. BDNF is necessary for the survival of dopaminergic neurons in substantia nigra. Val66Met is a common polymorphism of the BDNF gene that affects cognitive and motor processes. The authors studied 104 Brazilian patients with PD and 96 control participants. The G/G genotype was significantly associated with depression and anxiety symptoms and development of PD. This is the first study that associates this genotype with PD.

Lifting supra-auricular com uso de preenchedores: nova técnica / Supra-Auricular Lifting With Fillers: New Technique

Introdução: A evolução das técnicas de preenchimento possibilitou uma abordagem tridimensional da face: deixando-se de valorizar sulcos e optando-se pela restauração volumétrica. Objetivo: Descrição de técnica inédita de volumização facial por injeção de preenchedor na região supra-auricular, com revisão detalhada da anatomia regional. Métodos: Foi conduzido estudo retrospectivo de análise de casos, em pacientes apresentando mobilidade da pele na região têmporo-parietal. A injeção de ácido hialurônico para reposição volumétrica foi feita com cânulas, utilizando-se técnicas em bólus e em leque, na região supra-auricular, limitada ântero-superiormente pela área de implantação do cabelo e inferiormente pelo trágus. Os pacientes foram avaliados clínica e fotograficamente e tiveram seus dados analisados por estatística. Resultados: Foram tratados 152 mulheres e 13 homens de 24 a 84 anos, entre julho e setembro de 2016. O volume de ácido hialurônico utilizado nos pacientes variou de 0,6 a 2,6ml. Em oito casos observou-se abaulamento local devido a hematoma durante a aplicação, controlado por compressão digital. Constatou-se melhora significativa do contorno facial. Conclusão: O uso de preenchedor na região supra-auricular permite a abordagem tridimensional e promove o rejuvenescimento estático e dinâmico de toda a face.

Introduction: The evolution of filling techniques allowed a three-dimensional approach to the face: nowadays volumetric restoration is more important than grooves. Objective: Description of an unpublished technique of facial volumization through the injection of filler in the supra-auricular region, with a detailed review of the regional anatomy. Methods: A retrospective case-control study was conducted in patients presenting skin mobility in the temporo-parietal region. The injection of Hyaluronic Acid for volumetric replacement was done using cannulae, bolus and fan techniques in the supra-auricular region, limited antero-superiorly by the area of ¿¿hair implantation and inferiorly by the tragus. The patients were evaluated clinically, photographed and had their data analyzed by statistics. Results: 152 women and 13 men aged 24 to 84 years were treated between July and September 2016. The volume of Hyaluronic Acid used in the patients ranged from 0.6 to 2.6 ml. In 8 cases local edema was observed due to hematoma during application, that was controlled by digital compression. Significant improvement of the facial contour was observed. Conclusion: The use of fillers in the supra-auricular region allows a three-dimensional approach and promotes static and dynamic rejuvenation of the entire face.

Do suicide attempts occur more frequently in the spring too? A systematic review and rhythmic analysis.

BACKGROUND: Seasonal variations in suicides have been reported worldwide, however, there may be a different seasonal pattern in suicide attempts. The aim of this study was to perform a systematic review on seasonality of suicide attempts considering potential interfering variables, and a statistical analysis for seasonality with the collected data. METHOD: Observational epidemiological studies about seasonality in suicide attempts were searched in PubMed, Web of Science, LILACS and Cochrane Library databases with terms attempted suicide, attempt and season. Monthly or seasonal data available were evaluated by rhythmic analysis softwares. RESULTS: Twenty-nine articles from 16 different countries were included in the final review. It was observed different patterns of seasonality, however, suicide attempts in spring and summer were the most frequent seasons reported. Eight studies indicated differences in sex and three in the method used for suicide attempts. Three articles did not find a seasonal pattern in suicide attempts. Cosinor analysis identified an overall pattern of seasonal variation with a suggested peak in spring, considering articles individually or grouped and independent of sex and method used. A restricted analysis with self-poisoning in hospital samples demonstrated the same profile. LIMITATIONS: Grouping diverse populations and potential analytical bias due to lack of information are the main limitations. CONCLUSIONS: The identification of a seasonal profile suggests the influence of an important environmental modulator that can reverberate to suicide prevention strategies. Further studies controlling interfering variables and investigating the biological substrate for this phenomenon would be helpful to confirm our conclusion.

Synthesis and Solvatochromism of Substituted 4-(Nitrostyryl)phenolate Dyes.

4-(Nitrostyryl)phenols 2a-9a were synthesized, and by deprotonation in solution, the solvatochromic phenolates 2b-9b were formed. Their absorption bands in the vis region of the spectra are due to π-π* electronic transitions, of an intramolecular charge-transfer nature, from the electron-donor phenolate toward the electron-acceptor nitroarene moiety. The frontier molecular orbitals and natural bond orbitals were analyzed for the protonated and deprotonated forms. The calculated geometries are in agreement with X-ray structures observed for 4a, 6a, and 8a. The HOMO-LUMO energy gaps suggest that, after their deprotonation, an increase in the electron delocalization is observed. In the protonated compounds, the HOMO is primarily localized over the phenol ring and the C═C bridge. After deprotonation, it extends toward the entire molecule, including the NO2 groups. The solvatochromism of each dye was studied in 28 organic solvents, and it was found that all compounds exhibit a reversal in solvatochromism, which is interpreted in terms of the ability of the media to stabilize their electronic ground and excited states to different extents. The Catalán multiparameter equation is used in the interpretation of the solvatochromic data, revealing that the most important contribution to the solute/solvent interaction is the hydrogen-bond donor acidity of the solvent.

Invasive aspergillosis in a user of inhaled cocaine: rhinosinusitis with bone and cartilage destruction.

Aspergillosis is an infection caused by saprophytic fungi of the genus Aspergillus, which typically occurs in immunosuppressed individuals, but has also been reported in immunocompetent patients. The main routes of entry are the respiratory tract, skin, cornea, and ear, and the infection may be localized or disseminated by contiguity or vascular invasion. We report a severe case of rhinosinusitis with cutaneous involvement, caused by invasive aspergillosis, in an immunocompetent user of inhaled cocaine. Invasive aspergillosis related to cocaine abuse has not yet been reported in the literature. After itraconazole treatment and surgical debridement, complete clinical remission was achieved. Nasal reconstruction with a skin graft over a silicone prosthesis resulted in a satisfactory esthetic outcome.

Invasive aspergillosis in a user of inhaled cocaine: rhinosinusitis with bone and cartilage destruction

Aspergillosis is an infection caused by saprophytic fungi of the genus Aspergillus, which typically occurs in immunosuppressed individuals, but has also been reported in immunocompetent patients. The main routes of entry are the respiratory tract, skin, cornea, and ear, and the infection may be localized or disseminated by contiguity or vascular invasion. We report a severe case of rhinosinusitis with cutaneous involvement, caused by invasive aspergillosis, in an immunocompetent user of inhaled cocaine. Invasive aspergillosis related to cocaine abuse has not yet been reported in the literature. After itraconazole treatment and surgical debridement, complete clinical remission was achieved. Nasal reconstruction with a skin graft over a silicone prosthesis resulted in a satisfactory esthetic outcome.

Ureasil-poly(ethylene oxide) hybrid matrix for selective adsorption and separation of dyes from water.

Herein, we present a cross-linked ureasil-polyether-siloxane hybrid (labeled PEO500) that can function as a stimuli-sensitive material; it swells or shrinks in response to changes in the environmental conditions and it can also, effectively and selectively, remove dyes from water solution. We also developed a methodology to separate a mixture of cationic and anionic dyes present in water. Addition of PEO500 to an aqueous solution of the anionic orange II (OII) or the ponceau S (PS) dye rendered the solution colorless, but an aqueous solution of cationic methylene blue (MB) remained unchanged after 2 h of contact with the insoluble matrix. In situ small-angle X-ray scattering (SAXS) showed that the distance of siloxane nanodomains are strongly affected by the swelling or shriking. By in situ UV-vis adsorption experiments, we found that the kinetics of OII and PS removal followed a pseudo-first-order rate equation. We accomplished B3LYP calculations, to establish which sites on the matrix interacted with the dyes and to investigate the nature of the matrix-dye chemical bonds. On the basis of the experimental and theoretical investigations, we proposed some mechanisms to explain how PEO500 adsorbs anionic dyes efficiently. This "smart" matrix is potentially applicable as an efficient, fast, selective, and convenient device in water treatment and stimuli-sensitive response materials.

The two faces of hydrogen-bond strength on triple AAA-DDD arrays.

Systems that are connected through multiple hydrogen bonds are the cornerstone of molecular recognition processes in biology, and they are increasingly being employed in supramolecular chemistry, specifically in molecular self-assembly processes. For this reason, the effects of different substituents (NO2, CN, F, Cl, Br, OCH3 and NH2) on the electronic structure, and consequently on the magnitude of hydrogen bonds in triple AAA-DDD arrays (A=acceptor, D=donor) were evaluated in the light of topological [electron localization function (ELF) and quantum theory of atoms in molecules (QTAIM)], energetic [Su-Li energy-decomposition analysis (EDA) and natural bond orbital analysis (NBO)], and geometrical analysis. The results based on local H-bond descriptors (geometries, QTAIM, ELF, and NBO) indicate that substitutions with electron-withdrawing groups on the AAA module tend to strengthen, whereas electron-donating substituents tend to weaken the covalent character of the AAA-DDD intermolecular H-bonds, and also indicate that the magnitude of the effect is dependent on the position of substitution. In contrast, Su-Li EDA results show an opposite behavior when compared to local H-bond descriptors, indicating that electron-donating substituents tend to increase the magnitude of H-bonds in AAA-DDD arrays, and thus suggesting that the use of local H-bond descriptors describes the nature of H bonds only partially, not providing enough insight about the strength of such H bonds.