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Chiral allenes self-assembly following a cooperative mechanism into a supramolecular chiral aggregate consisting of two coaxial helices: the internal helix described by the allene stack and the external helix which consist in a 4-helix described by the four allene substituents. More precisely, this supramolecular aggregate possesses six axially chiral elements within its structure-the allene, the allene stack (internal helix) and the stacks of the four allene substituents (external 4-helix)-. Interestingly, slight variations in the magnitude of the tilting degree while keeping its P- or M- orientation (internal helix) can vary the orientation of the 4-axial motifs at the external helix. Thus, while (P)-1 produces a supramolecular helix with a Θ ca. 15° (P int ) and a M 1 /P 2 /M 1' /P 2' orientation of the four axial motifs at the periphery, (P)-2 produces a supramolecular helix with a Θ ca. 23° (P int ) and a P 1 /P 2 /P 1' /P 2' orientation of the four axial motifs at the external helix. As a result, the ECD spectra and the AFM images of the (P)-1 and (P)-2 supramolecular aggregates dominated by the 1 and 1' substituents of the chiral allene indicate opposite handedness although the chirality of the building block and the orientation of the allene stack are the same., (© 2024 The Author(s). Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

The Hugo ™ robotic assisted surgery system is a relatively new robotic platform developed by Medtronic. The study objective was to describe the experience of using Hugo ™ robotic assisted surgery in gynecological surgeries and compare robotic assisted surgery-related outcomes between complex and non-complex gynecological patients at the Pacifica Salud Hospital. We performed secondary data retrospective analysis of 144 consecutive patients who underwent gynecological surgery with Hugo ™ robotic assisted surgery system (Medtronic) at the Pacifica Salud hospital in Panama City from July 19, 2021, to August 3, 2023. Complex patients were defined as those with one or more risk factors for surgery complications. Descriptive analysis of participants' sociodemographic and robotic assisted surgery-related characteristics. Due to the non-normal distribution of the RAS-related numeric variables, we compared these variables between complex and non-complex cases of gynecological patients using Kruskal-Wallis's test. The study found that Hugo ™ robotic assisted surgery system was safe for gynecological surgery in patients with and without risk factors for developing major surgery complications. None of the patients experienced any complications, and they had short hospital stays with low blood loss without requiring a blood transfusion. The Hugo ™ robotic assisted surgery system was technically sound and did not present technical failures. The results could be a reference for adopting this technology and developing best practices in the Latin American region., Competing Interests: Declarations Conflict of interests Dr Miguel Cáceres is proctor of HUGO RAS in Medtronic PLC and he is also this study grant-recipient. Dr. Ricardo Perez Cuevas received consultant honoraria from Medtronic PLC. The rest of the authors have no relevant financial or non-financial interests to disclose. All authors declare their complete independence from Medtronic PLC during the entire research process and are solely responsible for the methods, results, concepts, and conclusions in this manuscript. Ethics approval This study was performed in line with the principles of the Declaration of Helsinki. The study protocol obtained Institutional Review Board approval of the Pacifica Salud Hospital (N#2586). Consent to participate The manuscript presents the results of the secondary data retrospective analysis of patients who underwent gynecological surgery with HugoTM RAS System (Medtronic), according to the institutional review bord the inclusion in the analysis of the deidentified patients’ data did not require their consent. However, all patients who underwent surgery with HugoTM RAS System gave written informed consent for robotic surgery and were personally informed by the operating surgeon about the surgical procedure and its possible complications. Consent to publish According to the institutional review bord the inclusion in the analysis of the deidentified patients’ data did not require their consent to publish., (© 2024. The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature.)

Molecular switches, supramolecular chemistry, and polymers can be combined to create stimuli-responsive multichiral materials. Therefore, by acting on the extended/bent conformational composition of an achiral arm, it is possible to create a macromolecular gear, where different supramolecular interactions can be activated/deactivated to control the helical sense of a polymer containing up to five different chiral axial motifs. For this, a chiral allene with a flexible achiral arm was introduced as a pendant in poly(phenylacetylene). Through flexible arm control between extended and bent conformations, it is possible to selectively induce either a P or M helical sense in the polymer, while the relative spatial distribution of the substituents in the allene remains unaltered in two perpendicular planes (configurationally locked). These results show that complex dynamic multichiral materials can be obtained by the polymerization of appropriate monomers that combine chirality, switching properties, and the ability to generate chiral supramolecular assemblies.

Helix inversion in chiral dynamic helical polymers is usually achieved by conformational changes at the pendant groups induced through external stimuli. Herein, a different mechanism of helix inversion in poly(phenylacetylene)s (PPAs) is presented, based on the activation/deactivation of supramolecular interactions. We prepared poly[(allenylethynylenephenylene)acetylene]s (PAEPAs) in which the pendant groups are conformationally locked chiral allenes. Therefore, their substituents are placed in specific spatial orientations. As a result, the screw sense of a PAEPA is fixed by the allenyl substituent with the optimal size/distance relationship to the backbone. This helical sense command can be surpassed by supramolecular interactions between another substituent on the allene and appropriate external stimuli, such as amines. So, a helix inversion occurs through a novel axial-to-helical communication mechanism, opening a new scenario for taming the helices of chiral dynamic helical polymers., (© 2023 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

Females present more neck/shoulder musculoskeletal disorders and have different activation strategies of the shoulder girdle muscles than males. However, the sensorimotor performance and potential sex differences are still largely unexplored. The aim of this study was to investigate sex differences in torque steadiness and accuracy during isometric shoulder scaption. We also examined the amplitude and variability of the activation of the trapezius, serratus anterior (SA), and anterior deltoid muscles during torque output evaluation. Thirty-four asymptomatic adults (17 females) participated. Torque steadiness and accuracy were evaluated during submaximal contractions at 20 % and 35 % of peak torque (PT). There was no sex difference in torque coefficient of variation, but females had significantly lower torque standard deviation (SD) values than males at the two intensities evaluated (p < 0.001) and lower torque median frequency values compared to males, regardless of intensity (p < 0.01). Females had significantly lower absolute error values than males for torque output at 35 %PT (p < 0.01) and lower constant error values compared to males, regardless of intensity (p = 0.01). Females had significantly higher muscle amplitude values than males, except for SA (p = 0.10) and in general, females showed higher muscle activation SD values compared to males (p < 0.05). Females may require more complex muscle activation patterns to achieve a more stable and accurate torque output. Therefore, these sex differences may reflect control mechanisms that may also be at play when explaining the greater risk of neck/shoulder musculoskeletal disorders in females than males., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Introduction: As soon as COVID-19 spread around the world, prevention and control measures were taken, such as masking and physical distancing, which changed people's routines, including musical practice among professional and amateur musicians., Objective: This descriptive questionnaire study was designed to: 1) investigate how the pandemic affected musical practice among musicians; 2) determine how musicians remained motivated in their new routine; 3) identify the presence of pre-COVID musculoskeletal symptoms; and 4) analyze whether musculoskeletal symptoms decreased, maintained, or increased during the COVID-19 pandemic., Methods: A total of 89 musicians from Brazil participated in an online survey, from August 2020 to January 2021. The survey form included questions about motivation, musical practice frequency, and the presence and characterization of musculoskeletal symptoms (adapted from the Nordic Musculoskeletal Questionnaire, NMQ). Musicians were asked to consider the periods before and during the pandemic to answer the questions., Results: During the pandemic, the frequency of musical practice decreased (p<0.01), and it could be associated with the individual's perceptions of motivation. Musculoskeletal symptoms in the previous 12 months were reported by 58%. When comparing the period before the pandemic to the present, 35.3% of musicians reported their musculoskeletal symptoms had not changed, while 33.3% reported that they had increased. Wrists and hands, lower and upper back, shoulders, and neck were the body sites with most frequent complaints., Conclusion: The COVID-19 pandemic had a negative impact on the frequency of musical practice of the musicians assessed in this study, with a significant decrease in practice time. Musculoskeletal symptoms were present in this population prior to the pandemic, and these symptoms were mostly maintained or worsened.

Stimuli-responsive supramolecular receptors are important building blocks for the construction of self-assembled functional materials. We report the design and synthesis of a pH- and light-responsive 2-hydroxychalcone-β-cyclodextrin conjugate ( 1-Ct ) and its characterization by spectroscopic and computational methods. 1-Ct follows the typical reaction network of trans -chalcone-flavylium photoswitches. Upon light irradiation, 1-Ct can be photochemically converted into the cis -chalcone/hemiketal forms ( 1-Cc / 1-B ) under neutral pH conditions or to the flavylium cation ( 1-AH + ) at acidic pH values. This stimuli-responsive β-cyclodextrin host, 1-Ct , was found to form stronger intramolecular self-inclusion complexes ( K intra = 14) than 1-AH + ( K intra = 3) and weaker than 1-Cc / 1-B (overall K intra = 179), allowing control over their stability and binding properties by combinations of pH and light stimuli.

Objective: The purpose of this study was to evaluate the intra-rater between-days reliability of the joint position sense error (JPSE) test in asymptomatic men and women, as well as in women with neck pain., Methods: Fourteen asymptomatic men and 27 women (14 asymptomatic and 13 with neck pain) participated. The JPSE test was performed during right and left cervical rotation (10 trials for each side) in 2 sessions, with at least 7 days between them. The head repositioning error during the JPSE test (in degrees) was measured and used to calculate the intra-rater between-days reliability of the test, evaluated through the intraclass correlation coefficient and Bland-Altman analyses. Independent t tests were calculated to compare the head repositioning errors of asymptomatic women and men. The minimal detectable change was also calculated., Results: The neck pain group showed higher intraclass correlation coefficient values (0.866 and 0.773, good reliability) compared to the asymptomatic men (0.478 and 0.403, poor reliability) and to the asymptomatic women (-0.161 and 0.504, poor and moderate reliability, respectively) for both right and left cervical rotation, respectively. Considering Bland-Altman analyses, the neck pain group showed better agreement between the measurements for right cervical rotation than the asymptomatic groups., Conclusion: The results indicate that the methodology used to perform the JPSE test in this study may be a reliable way to assess the proprioception of women with neck pain in clinical settings., (Copyright © 2022. Published by Elsevier Inc.)

There is great variability regarding serratus anterior sEMG sensor placement and test positions during normalization procedures. We investigated between-trials reliability of serratus anterior sEMG, acquired at two sensor placements and four test positions, during maximal and submaximal isometric contractions. Twenty young healthy women participated. sEMG was captured at the 7 th intercostal space and at the xiphoid process level, in the mid-axillary line, during maximal and submaximal isometric contractions, in four test positions. Intraclass Correlation Coefficient (ICC 2,1 ), coefficient of variation and standard error of measurement were calculated. Interactions between sensor placements and test positions were investigated using a two-way repeated-measures ANOVA. All test conditions presented ICC 2,1  > 0.8. There was no interaction between sensor placement and test position. Signal obtained from the sensor at 7 th intercostal space was more stable between-trials and showed higher amplitude, during maximal and submaximal contractions, at seated positions with shoulder protracted at both 90° or 125° of flexion. We suggest to acquire serratus anterior sEMG at the 7th intercostal space and perform maximal or submaximal isometric contractions for signal normalization with shoulder protracted and flexed, at seated position., (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

A series of bidentate allene- and enyne-containing ligands have been synthesized and the photochemical properties of their rhenium(I) complexes have been studied. These complexes exhibit facile isomerization of the conjugated double bonds upon ambient light exposure. Simulations unveiled a very efficient intersystem crossing and the consequent key role of the triplet states in the observed photochemistry of these substrates upon rhenium(I) complexation.

Chirality, a characteristic tool of molecular recognition in nature, is often a complement of redox active systems. Scientists, in their eagerness to mimic such sophistication, have designed numerous chiral systems based on molecular entities with cavities, such as macrocycles and cages. In an attempt to combine chirality and redox-active species, in this contribution we report the synthesis and detailed characterization of a chiral shape-persistent molecular cage based on the combination of enantiopure diethynylallenes and electron-rich bridged triarylamines, also known as N-heterotriangulenes. Its ability for chiral recognition in solution was revealed through UV/vis titrations with enantiopure helicenes., (© 2021 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)

On the basis of experimental data and density functional theory (DFT) chemical shift and scalar coupling predictions, simple spectral nuclear magnetic resonance (NMR) fingerprint patterns have been established for the determination of the configuration in 1,3:2,4-dibenzylidene-d-sorbitol (DBS), a classic low molecular weight gelator, and its derivatives. The results rigorously prove the orientation of the phenyl rings in DBS that had been previously assumed in the literature on the basis of thermodynamic arguments., (© 2020 John Wiley & Sons, Ltd.)

The aim of this study was to evaluate if there are sex differences in postures of upper arm, upper back, head and neck after muscle fatigue induced by a simulated work task, requiring upper arm movements performed above shoulder level. Nineteen females and 18 males were evaluated. Upper arm elevation, upper back, head and neck forward flexion postures were recorded using digital inclinometers. The first and the last cycles of the task were considered as pre- and post-fatigue periods, respectively. For both periods, Amplitude Probability Distribution Function (APDF) was calculated for 10th, 50th and 90th percentiles, as well as the angular ranges between the 5th and 95th percentiles (APDF 5-95 range). The APDF 5-95 range for upper arm elevation was higher with fatigue, but with a higher increase for males. After fatigue, there was also a decrease in the upper arm elevation, with a larger decrease in males for the 10th and 50th percentiles. For head and neck, females showed higher APDF 5-95 ranges than males, regardless of the task period evaluated. After muscle fatigue, males adopted more neutral postures of the upper arm than females. Furthermore, females showed more non-neutral postures for head and neck. These findings suggest that the kinematic strategies adopted by females and males during a simulated work task are different and may predispose females to a higher risk of developing work-related musculoskeletal disorders of the neck., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

A photochemical two-step one-pot synthesis of novel biscyclopropyl-box-shaped compounds via the reaction of 2,5-dimethoxy- para -benzoquinone and monosubstituted alkynes is reported. The reaction mechanism for a process in which six new C-C bonds are formed is explored by means of experimental and computational techniques. The whole process occurs with complete selectivity, and only one densely decorated diastereomer is obtained; such a degree of control and substitution makes for a rather powerful and complexity-building process.

The aim was to investigate if the method of normalizing surface electromyography (sEMG) can change results on sex differences in the muscular activation of the shoulder girdle muscles during a simulated work task. sEMG was recorded in 36 asymptomatic participants (17 females, 19 males) from four parts of trapezius and from serratus anterior muscles during a simulated work task. Four normalization methods, one involving maximal voluntary contractions (MVCs) and three involving submaximal voluntary contractions were applied. Sex differences in absolute and normalized amplitude of sEMG were analyzed. The normalization method had a significant influence on the observed sex differences. Females only showed higher sEMG amplitude than males when the sEMGs were normalized to MVC and to a submaximal contraction based on 20% of MVC for the upper trapezius (acromial fibers). Researchers and practitioners should be aware of the impact of the sEMG normalization method in sex differences investigation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Background: There are few reports in the literature supporting the understanding of the physiological mechanisms of intolerance in patients with COPD to perform unsupported upper limb activities. The aims of this study were to quantify the electrical activity and oxygenation of inspiratory and upper limb muscles, and to investigate whether electromyographic manifestations of muscle fatigue are related to upper limb function as assessed by the 6-min pegboard and ring test (6PBRT) in subjects with COPD and in healthy subjects., Methods: Thirty subjects with COPD (FEV 1 42.1 ± 16.4% predicted; 68.0 ± 7.6 y old) comprised the COPD group, and 34 healthy subjects (66.8 ± 8.0 y old) comprised the control group. Both groups were assessed for body composition with dual-energy radiograph absorptiometry and spirometry. The 6PBRT was performed with simultaneous assessment of electromyography, near-infrared spectroscopy, and gas analyses (expiratory minute volume)., Results: Differences were observed between groups for performance (number of rings) in the 6PBRT, with the COPD group achieving lower values than the control group ( P < .001). The ventilatory demand (expiratory minute volume/maximum voluntary ventilation) and root mean square amplitude of the sternocleidomastoid muscle were higher in the COPD group than in the control group ( P < .04). Lower values for oxyhemoglobin and total hemoglobin were found in intercostal muscles of the COPD group compared to the control group. The root mean square amplitude of the intercostal muscles was lower in the COPD group, while it was similar between groups for anterior deltoid and trapezius muscles. Median frequency of anterior deltoid muscles presented a decreased in both groups., Conclusions: Our results indicate that the 6PBRT was performed at a higher electrical activity in the accessory inspiratory muscles, such as the sternocleidomastoid muscle, and a lower oxygenation profile in the intercostal muscles in subjects with COPD compared with healthy controls, but without muscle fatigue signs. These findings suggest that the higher ventilatory demand presented in subjects with COPD could have contributed to the worse performance in this group without signals of peripheral muscle limitation., (Copyright © 2020 by Daedalus Enterprises.)

We prove that the confinement of the conformational space of pyridoallenophanes leads to intense chiroptical responses. Unlike the cyclic dimer [14 2 ], single-conformation [14 1 ]pyridoallenophanes isomerize under thermal and photochemical conditions. Yet, less-strained [14 1 ]-bipyridoallenophanes are stable and are prepared successfully. They, unexpectedly, undergo double protonation as a result of cooperative ion-pairing and hydrogen bonding. The complex formation forces a single configuration of the axis connecting both pyridyl rings recognized by a diagnostic circular dichroism (CD) signal at 330 nm.

Purpose: The higher prevalence of work-related musculoskeletal disorders among women compared with men could be explained by sex-gender differences related to biological and physiological processes. The aim of this study was to evaluate sex differences in motor coordination during a sustained and repetitive motor task., Methods: Seventeen healthy females and 21 healthy males participated. The surface electromyography (sEMG) of the trapezius portions and serratus anterior were recorded. Root mean square (RMS) values were computed to assess the level of muscle activity. The standard deviation (SD) and coefficient of variation (CV) were computed as metrics of size of variability. The normalized mutual information (NMI) values were calculated as index of functional connectivity between muscles pairs., Results: Females had higher normalized RMS values for the upper trapezius (acromial fibers) and serratus anterior muscles compared with males. RMS decreased, SD and CV increased while NMI decreased for almost all muscle pairs over time., Conclusion: The present work showed some signs of sex differences in muscle coordination of the shoulder girdle during a sustained motor task, performed with the upper limb positioned below of the shoulder level., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

(1) Background : Epidural analgesia (EA), at the present time, is one of the most effective methods to reduce labor pain. In recent years its use has increased, being used between 20⁻70% of all deliveries; (2) Methods : Historical cohort on a total of 2947 deliveries during the years 2012⁻2016 at the "Mancha-Centro Hospital" of Alcázar de San Juan. The main outcome variables were four neonatal morbidity (NM) criteria: umbilical artery pH of <7.10, Apgar score at 5 min < 7, need for advanced resuscitation and composite morbidity. We used the multivariate analysis to control confounding bias. (3) Results : No statistical relationship between EA and the second stage of labor duration with none of the four criteria of NM used ( p > 0.005). However, the type of delivery was associated with three criteria (pH, resuscitation, and composite morbidity). The instrumental delivery presented an OR of pH < 7.10 of 2.68 95% CI [1.15, 6.27], an OR of advanced resuscitation of 2.44 95% CI [1.17, 5.08] and OR of composite morbidity of 2.86 95% CI [1.59, 5.12]; (4) Conclusions : The EA and the second stage of labor duration are not related to the NM. While the instrumental delivery doubles the risk of NM compared to the normal vaginal delivery.

Objective: Parenteral nutrition consists of the intravenous administration of macronutrients, micronutrients and electrolytes. Our objectives were to evaluate the biochemical alterations during the first ten days of initiation and to quantify the bacteremia related to the central venous catheter during the administration of parenteral nutrition., Material and Methods: Retrospective study of incidence and prevalence. We included 51 patients who started intravenous nutritional support therapy at Critical Care. We intend to know the infectious complications of the central line associated with parenteral nutrition, to evaluate the most frequent hydroelectrolytic complications of parenteral nutrition, and to identify minimum control points in the detection of hydroelectrolytic alterations., Results: Statistically significant daily variations were found for glucose, magnesium, potassium and creatinine, and bordering on the statistical significance for albumin and phosphate, the alterations occurring between the second and third days fundamentally. Hypoalbuminemia and hypocalcemia were very frequent. GGT was the liver enzyme that increased more frequently. The infection rate was 14.86 per 1,000 days of central venous catheter., Conclusions: We found daily variations in glucose, potassium and magnesium, as well as a decrease in creatinine. We emphasize the frequency of hypoalbuminemia, hypocalcemia and elevation of GGT. The most important variations occurred between the second and third day, highlighting the precocity of potassium alteration and the peak of glycemia. The rate of infection related to the central venous catheter in patients with parenteral nutrition was high., (Copyright © 2018 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.)

Objective: To evaluate within- and between-days reliability of two normalization methods of surface electromyography (sEMG) recordings of the trapezius muscle., Methods: Nineteen women were allocated into 2 groups (healthy and with neck-shoulder pain). The sEMG was recorded in two sessions with 7 days in between sessions. The four portions of the trapezius muscle (the clavicular and acromial fibers of the upper trapezius, the middle and the lower trapezius) were evaluated during maximal and submaximal isometric voluntary contractions. The within- and between-days reliability of both maximal and submaximal contractions were assessed through Intraclass Correlation Coefficient (ICC (2,1) was used for within-day analyses of both maximal and submaximal contractions, and for between-days analyses of maximal contractions while ICC (2,3) was used for between-days analyses of submaximal contractions), Coefficient of Variation, Standard Error of Measurement, and Bland-Altman analysis., Results: In general, submaximal contractions presented higher within-day reliability, with higher ICC values (e.g., middle trapezius - mean of 0.97), smaller Coefficient of Variation and Standard Error of Measurement ranges compared to maximal contractions (ICC values, e.g. for middle trapezius - mean of 0.94) in both groups. The same pattern was observed for between-days analyses, with submaximal contractions presenting higher ICC values (e.g., middle trapezius - mean of 0.84), smaller Coefficient of Variation and Standard Error of Measurement ranges than maximal contractions (ICC values, e.g. for middle trapezius - mean of 0.73) in both groups., Conclusion: Submaximal contractions are recommended for normalization procedures of trapezius sEMG, in both subjects with neck-shoulder pain and healthy individuals., (Copyright © 2017 Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia. Publicado por Elsevier Editora Ltda. All rights reserved.)

This study investigated the acute effects of changing the work pace and implementing two pause types during an assembly task. Eighteen healthy women performed a simulated task in four different conditions: 1) slow or 2) fast work pace with 3) passive or 4) active pauses every two minutes. The root mean square (RMS) and exposure variation analysis (EVA) from the trapezius and serratus anterior muscles, as well as the rate of perceived exertion (RPE) from the neck-shoulder region, were observed. Decreased RMS and RPE as well as more variable muscle activity (EVA) were observed in the slow work pace compared with the fast one. The pause types had a limited effect, but active pauses resulted in increased RMS of the clavicular trapezius. The findings revealed the importance of work pace in the reduction of perceived exertion and promotion of variation in muscle activation during assembly tasks. However, the pause types had no important effect on the evaluated outcomes., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Chromonic liquid crystals (CLC) are lyotropic phases formed by discotic mesogens in water. Simple chiral dopants such as amino acids have been reported to turn chromonic liquid crystals into their cholesteric counterparts. Here we report a chirality amplification effect in the nematic phase of a 9 wt% disodium cromoglycate (DSCG) lyotropic liquid crystal (LLC) upon doping with a water-soluble codeine derivative. The transition on cooling the isotropic to the nematic phase showed the presence of homochiral spindle-shaped droplets (tactoids). NMR DOSY experiments on a triple gradient probe revealed a small degree of diffusion anisotropy for the alkaloid embedded in the liquid crystal structure. These results in combination with XRD, CD and POM experiments agree with a supramolecular aggregation model based on simple columnar stacks.

Purpose: The aim of this study was to evaluate the coordination of the shoulder girdle muscles among subjects with or without neck-shoulder pain performing repetitive arm movement at either a slow or fast pace., Methods: Thirty female adults were allocated to one of two groups-healthy controls or cases with neck-shoulder pain. Surface electromyography (sEMG) signals from the clavicular, acromial, middle and lower trapezius portions and the serratus anterior muscles were recorded during a task performed for 20min at a slow pace and 20min at a fast pace. The root mean square (RMS), relative rest time (RRT) and normalised mutual information (NMI, an index of functional connectivity between two muscles in a pair) were computed., Results: No significant differences on RMS, RRT and NMI were found between groups. For both groups, the fast movement pace resulted in increased levels of RMS, lower degrees of RRT and higher NMI compared to the slow pace. No interaction between group and movement pace was found., Conclusions: This study highlights the change in sEMG activity of muscles to meet the demands of performing a task at fast movement pace. The fast pace imposed a higher muscle demand evidenced by increased sEMG amplitude, low degree of muscle rest and increased functional connectivity for subjects in both the case and control groups. No indication of impaired sEMG activity was found in individuals with neck-shoulder pain., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Active pauses have shown potentially beneficial effects to increase the variability of the electrical activation pattern of muscles. However, there is a lack of consensus as to how to design and implement those pauses and the processing methods of surface electromyography (EMG) data when evaluating low-level monotonous tasks. The aim of this systematic review was to synthesize the evidences regarding the way which active pauses have been applied, and the methods used to investigate the related EMG changes. PubMed-MEDLINE, Embase, Web of Science, Lilacs, Ebsco, and Scopus databases were searched. Two authors independently extracted data from the primary studies. The methodological quality was assessed using a list from van der Windt et al. (2000), and the level of evidence was synthesized through GRADE. The ISEK guideline for reporting EMG data was also applied as a checklist. Fifteen studies were included - 14 with high methodological quality. In general, active pauses were able to change the level of EMG activity in monotonous tasks. The level of evidence through GRADE was very low for all EMG processing methods, except RMS which was low. A vast heterogeneity concerning the methods applied to analyze EMG data contributed to decrease the quality of evidence synthesis, and the findings need to be carefully considered. The GRADE approach and the ISEK guideline contributed to identify important flaws in the literature. Future studies investigating active pauses in longitudinal studies and following the standard for recording and reporting EMG data care are warranted., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

A combined experimental-computational analysis of the one- and two-photon absorption (OPA, TPA) and the electronic circular dichroism (ECD) of complex chiral shape-persistent (2,6)-pyrido[142 ]allenoacetylenic cyclophane, (P,P,P,P)-MC[142 ] enantiomers, sheds light on the origin of their peculiar spectral signatures. The study on MC[142 ], which is represented in solution by three possible conformers, indicates that two of them (chair and twist) are the prevalent conformers at room temperature; the population ratio depending on the solvent. The complex shape of the red-edge of the UV and ECD spectra is qualitatively reproduced by using vibronic calculations and assigned to progressions on the ethynyl stretchings observable only in the chair and twist conformers. The picture arising from the analysis of the linear spectra is confirmed by two-photon spectroscopies, showing that they constitute valuable tools for the exploration of high-energy electronic transitions in pyridoallenoacetylenic cyclophanes. Discrepancies among computed and experimental spectra point out that an accurate description of such complex systems with a large delocalized π framework and a dense manifold of electronic excited state remains a challenge for theoretical models., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Chiral macrocycles offer great potential and versatility regarding their applications. They have been employed in asymmetric catalysts, as chiral sensors, and as chiral supramolecular frameworks. For these reasons, they have been attracting increasing interest over the years. Despite all of the work developed in this area, most of the reported chiral macrocycles are not conformationally stable and present weak chiroptical responses. Such features substantially limit the scope of applications for these compounds. On the other hand, we have shown that axially chiral allenes can be introduced into macrocycles, conferring conformational stability and outstanding chiroptical responses. However, these allenes photoisomerize when conjugated with electron-donating groups, hampering the possibility of synthesizing systems with tuned optical properties. To overcome all of these limitations with a single structural motif, we propose the use of spiranes to construct new stable, conformationally rigid, and chemically functionalizable macrocyclic structures with strong chiroptical responses. As a first step in this new direction, we theoretically predict the chiroptical responses for macrocycles bearing spiranes to be as strong as with their allenic counterparts. As a side product, we also test the popular Minnesota functional, M06-2X, and compare it with cam-B3LYP, which has been previously analyzed with respect to experimental data in our laboratory. Thus, we hereby propose that spiranes are a good alternative to allenes for the construction of new chiral macrocycles.

Chiroptically active allenes are employed for the construction of surface-confined nanostructures. Morphological complementarity between the homochiral units leads to self-assembly of two highly-ordered, upstanding, diastereomeric architectures. The novel, intertwined self-assembled layer structures feature reactive terminal alkynes for further functionalization and carry potential for widespread applications exploiting chiroptical amplification.

Chromonic phases are a family of lyotropic liquid crystals (LC) formed by ionic aromatic mesogens such as disodium cromoglycate (cromolyn), sunset yellow and others. It is well known that chromonic phases are oriented in the presence of external magnetic fields, leading to the observation of anisotropic NMR observables such as quadrupolar splittings or residual dipolar couplings. Despite the fact that the cromolyn nematic LC phase (N) presents important advantages like great homogeneity, small line broadening, and easy sample preparation, it has been scarcely used as a water-compatible NMR orienting medium, in part due to a too strong induced degree of alignment on the guest molecules. However, the use of cromolyn-brine mixtures led to the optimum degree of alignment allowing to record (1)H-(13)C dipolar couplings with good accuracy.

A chiral bidentate inclusion complex has been formed by halogen-bond interaction between the pyridyl moieties of a pyridoallenoacetylenic host and octafluorodiiodobutane. X-ray crystallography showed that the guest adopts a chiral conformation inside the molecular channels formed by stacking of the host units. A 10 ppm shielding of the (15)N NMR resonance for the pyridil units provided evidence of the formation of the halogen-bond complex in solution.

The photochemical isomerization of resveratrol has been the subject of recent studies in which contradictory results were reported. The photoproduct mixture of this reaction needs to be considered more complex than the coexistence of cis and trans isomers. An unidentified third product, at least, has been detected in various studies although its nature was unknown. In this work, we aim to provide a thorough description of the photochemical course of this reaction through experimental and computational approaches working in a synergetic association.

New 2,6-disubstituted pyrido-allenophanes with locked rotation of aromatic spacers were designed and synthesized. The synthesis was accomplished by Pd-catalyzed C(sp(2))-C(sp) Sonogashira cross-coupling reaction between 1,3-diethynylallene (DEA) and 2,6-dibromopyridine followed by an intermolecular ring closure. Because racemic DEA was employed, pyrido-allenophanes were obtained as mixtures of stereoisomers that were resolved by preparative HPLC. The conformational space of all these diastereoisomers was explored at the CAM-B3LYP/6-31+G*//AM1 level of theory. The isomers were characterized through their symmetry properties revealed in NMR, circular dichroism, and chiral stationary-phase HPLC experiments. X-ray diffraction was used to assign and to corroborate the configuration of several diastereoisomers. The unexpected encapsulation of two molecules of CHCl(3) in the crystal structures shows the potential of these conformationally hampered allenophanes as encapsulating hosts., (Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The mechanism of the acetylene homologation procedure accidentally discovered and further developed by Crabbé and coworkers is unknown. Kinetic isotope effect (KIE) experiments, however, suggest that an intramolecular hydrogen shift is the key step of the transformation. In this work, we present a computational study of this mechanism. We found that the reaction proceeds via an unexpected stepwise retro-imino-ene rearrangement. This mechanism justifies the role of Cu(I) as a reaction catalyst and is also compatible with the KIE experiments reported., (Copyright © 2012 Wiley Periodicals, Inc.)

In previous work, (E)-2-enynyl pyridines were reported to yield indolizinyl singlet carbenes through base-catalyzed E/Z isomerization followed by a 5-exo-dig pseudocoarctate cyclization. We report herein that in the presence of ethyl acrylate these carbenes undergo stereoselective cis-cyclopropanation due mainly to electrostatic interactions in the transition state. The scope of this carbene generation scheme has been further explored through the preparation of a symmetric bis(pyridylenyl)alkyne which spontaneously furnished the biindolizine core in a one-pot reaction. Computational characterization of this transformation suggests a highly asynchronous double cyclization., (© 2011 American Chemical Society)

2,3,7-Trisubstituted indolizines were obtained from E- or Z-2-enynyl-4-substituted pyridines. The mechanistic pathway involves a base-catalyzed double-bond isomerization, if the E-isomer is the starting material, followed by a concerted pseudocoarctate cyclization.

Chiral pyridoallenophanes! The synthesis and characterization of chiral acetylenic pyridoallenophanes along with 2,4- and 2,5-pyridyl[Re(CO)(4)LBr] complexes are reported. The relative configurations of the four stereoisomers have been unambiguously assigned. Chromatographic resolution of the racemate of the C(4) stereoisomer was accomplished and mirror-image CD spectra have been obtained (see figure).Chiral macrocycles bearing four 2,5-substituted pyridine units have been prepared regioselectively. The four possible diastereoisomers (twist, chair, crown, and boat) were obtained in the reaction and separated by preparative HPLC. The isomers were fully characterized through their chirality and also their symmetry properties, taking into account the number of nonequivalent cumulenic carbon atoms in the (13)C NMR spectra. The reaction of the isolated twist cyclophane with [Re(CO)(5)Br] led to an uncommon tetracarbonyl rhenium complex [Re(CO)(4)L]. The arrangement of the ligands around the metal core was studied through the 2,4- and 2,5-bis(ethynylallenylethynylpyridyl) model compounds by analysis of their NMR, IR, and UV/Vis spectra.

[chemical reaction: see text]. A stereoselective total synthesis of the visual pigment A2E has been achieved with use of palladium-catalyzed cross-coupling reactions in all key steps: a regioselective Suzuki or Negishi coupling of 2,4-dibromopyridine, a Sonogashira reaction, and a double Stille cross-coupling to complete the bispolyenyl skeleton.

Buta-2,3-dienoate reacts with vinyl ketenimine to give the corresponding substituted aniline through a Diels-Alder cycloaddition. Besides the expected Diels-Alder adduct 3a, the aniline 3b was also obtained in a ratio of 91:9. The observed (13)C exchange is explained on the basis of a reversible [2 + 2] cycloaddition competing with the [4 + 2] process. This is supported by B3LYP DFT computations, as a stepwise pathway lies very close in energy to the [4 + 2] concerted one. [reaction: see text]

The myelinated axon can be modeled by means of a distributed RGC circuit. The Green function of this model allows for a generic formulation of the internodal segment response to any kind of stimulus, and accounts for the delay of the action potential associated with this segment. The RGC model accuracy is comparable to that of a more complex electromagnetic model, and predicted delay agrees with experimental measurements.

The alkaloid lennoxamine (1) was synthesized by transannular cyclization of a 10-membered lactam obtained by intramolecular addition of an aryl radical to a (trimethylsilyl)acetylene. The isoindolo[1,2-b][3]benzazepine skeleton present in lennoxamine was also obtained by means of regioselective 7-endo-trig radical cyclization of methylenephthalimidines.

A series of cyproheptadine related compounds was synthesized and tested pharmacologically. In comparison with cyproheptadine, these compounds do not have a central ring and some contain groups other than N-methyl. Synthesis was carried out with low-valent titanium to generate the exocyclic double bond. The serotoninergic activity of the compounds was determined by standard determination of pA2 (-log of the motor concentration of antagonist required to maintain a constant response when concentration of agonist is doubled) for the inhibition of serotonin-induced contractions in rat stomach fundus. Two of the nitrogen-containing compounds were active, but their activities were lower than that of cyproheptadine. Structure-activity relationships were studied by Mulliken net charges, molecular electrostatic potentials, and conformational analysis; activities are better correlated with electrostatic potentials than with net charges. The decrease in potency of the open cyproheptadine analogues may be due to "dilution" of the active conformer as the result of their conformational flexibility.