Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 134
Filtrar
1.
Int Urogynecol J ; 2024 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-39235505

RESUMO

INTRODUCTION AND HYPOTHESIS: Coital incontinence (CI) is common, with a significant impact on quality of life and sexual function. This multicentre study was aimed at measuring the association between overactive bladder (OAB), stress urinary incontinence (SUI) and different aspects of CI including orgasm and penetration incontinence. METHODS: Following ethical approval, data from the electronic Personal Assessment Questionnaire-Pelvic Floor patient-reported outcome measure was collated for Urogynaecology outpatients from seven participating UK Hospitals between April 2018 and January 2022. Data were anonymised and analysed centrally using Excel. RESULTS: A total of 12,877 responses were obtained, of which 4,843 were valid for inclusion. 79.3% of women presented with urinary incontinence of whom 41.6% also reported CI. 96.8% of women with CI reported mixed OAB and SUI, with 2.1% and 1.1% reporting pure OAB and SUI respectively. There was a small subset (2.4%) with no overt urinary incontinence who occasionally experienced CI. Spearman's rank-order correlation demonstrated a statistically significant association between CI symptom score with both SUI (R = 0.57, p < 0.001) and OAB (R = 0.40, p < 0.001); orgasm incontinence with SUI (R = 0.49, p < 0.001) and OAB (R = 0.36, P < 0.001); penetration incontinence with SUI (R = 0.48, p < 0.001) and OAB (R = 0.35, p < 0.001). CONCLUSIONS: Coital incontinence is experienced by 42% of women with urinary incontinence. There is a statistically significant association between both SUI and OAB with orgasm incontinence and penetration incontinence, suggesting (a) common underlying mechanism(s). Limitations of this study include the large amount of missing data and the NHS outpatient setting that limit the conclusions that can be drawn from the data.

2.
R Soc Open Sci ; 11(9): 240574, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39323555

RESUMO

Wild bovids provide important ecosystem functions as seed dispersers and vegetation modifiers. Five wild bovids remain in Thailand: gaur (Bos gaurus), banteng (Bos javanicus), wild water buffalo (Bubalus arnee), mainland serow (Capricornis sumatraensis) and Chinese goral (Naemorhedus griseus). Their populations and habitats have declined substantially and become fragmented by land-use change. We use ecological niche models to quantify how much potential suitable habitat for these species remains within protected areas in Asia and then specifically Thailand. We combined species occurrence data from several sources (e.g. mainly camera traps and direct observation) with environmental variables and species-specific and single, large accessible areas in ensemble models to generate suitability maps, using out-of-sample predictions to validate model performance against new independent data. Gaur, banteng and buffalo models showed reasonable model accuracy throughout the entire distribution (greater than or equal to 62%) and in Thailand (greater than or equal to 80%), whereas serow and goral models performed poorly for the entire distribution and in Thailand, though 5 km movement buffers markedly improved the performance for serow. Large suitable areas were identified in Thailand and India for gaur, Cambodia and Thailand for banteng and India for buffalo. Over 50% of suitable habitat is located outside protected areas, highlighting the need for habitat management and conflict mitigation outside protected areas.

3.
J Am Chem Soc ; 146(28): 19193-19204, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-38956456

RESUMO

There has been much effort to improve excited-state lifetimes in photosensitizers based on earth-abundant first-row transition metals. Copper(I) complexes have gained significant attention in this field, and in most cases, sterically driven approaches are used to optimize their lifetimes. This study presents a series of three-coordinate copper(I) complexes (Cu1-Cu3) where the excited-state lifetime is extended by triplet-triplet energy transfer. The heteroleptic compounds feature a cyclohexyl-substituted ß-diketiminate (CyNacNacMe) paired with aryl isocyanide ligands, giving the general formula Cu(CyNacNacMe)(CN-Ar) (CN-dmp = 2,6-dimethylphenyl isocyanide for Cu1; CN-pyr = 1-pyrenyl isocyanide for Cu2; CN-dmp-pyr = 2,6-dimethyl-4-(1-pyrenyl)phenyl isocyanide for Cu3). The nature, energies, and dynamics of the low-energy triplet excited states are assessed with a combination of photoluminescence measurements at room temperature and 77 K, ultrafast transient absorption (UFTA) spectroscopy, and DFT calculations. The complexes with the pyrene-decorated isocyanides (Cu2 and Cu3) exhibit extended excited-state lifetimes resulting from triplet-triplet energy transfer (TTET) between the short-lived charge-transfer excited state (3CT) and the long-lived pyrene-centered triplet state (3pyr). This TTET process is irreversible in Cu3, producing exclusively the 3pyr state, and in Cu2, the 3CT and 3pyr states are nearly isoenergetic, enabling reversible TTET and long-lived 3CT luminescence. The improved photophysical properties in Cu2 and Cu3 result in improvements in activity for both photocatalytic stilbene E/Z isomerization via triplet energy transfer and photoredox transformations involving hydrodebromination and C-O bond activation. These results illustrate that the extended excited-state lifetimes achieved through TTET result in newly conceived photosynthetically relevant earth-abundant transition metal complexes.

4.
Eur J Obstet Gynecol Reprod Biol ; 298: 18-22, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38705009

RESUMO

OBJECTIVES: Follow-up appointments in the UK National Health Service account for up to two thirds of outpatient activity, but there is a significant resource impact in providing time fixed follow-up appointments. Increasingly patient initiated follow-up is being used, to make follow-up appointments work better for patients both in terms of timing and necessity, and to reduce unnecessary outpatient activity. The objective of this study was to use a modified questionnaire to evaluate patient and clinician views regarding Patient-Initiated Follow-Up (PIFU) in gynaecology services and identify subgroups suited to this pathway of care. STUDY DESIGN: Participants including both patients and clinicians were recruited from a gynaecology outpatient department. Patients who have poorer access healthcare (with disabilities and black and ethnic minority background) were purposively targeted so their experiences could be included. Value and burden scores were evaluated using patient and clinician surveys based on a modified QQ-10 questionnaire which assessed perceived value and burden of patient initiated follow-up in gynaecology. Free text comments regarding PIFU were also collected. RESULTS: 305 patients and 30 clinicians were surveyed. Overall response to patient initiated follow-up was positive. Patients and clinicians attributed high value (77.4 % and 81.4 %) and low burden scores (37.5 % and 44.7 %) to PIFU. Patient autonomy was cited as a reason for this by 84.6 % of patients and 93.3 % of clinicians. Patients attending benign gynaecological sub-specialties including endometriosis (84.2), general gynaecology (82.5) and vulval clinics (81.4) attributed the highest value scores. Gynaecology oncology patients attributed the lowest value (64.0) and highest burden score (51.3) of all subgroups. Younger adults (<60) were more likely to express a preference for PIFU (52.9 %) than older adults (≥60) (28.6 %). CONCLUSIONS: In this study, both patients and clinicians are in favour of selected use of PIFU in gynaecology services. Both questionnaires found younger patients with benign gynaecological conditions were perceived as best suited PIFU. We recommend offering PIFU to select patients who are confident in self-monitoring, factoring patient choice so patients are not disadvantaged by this system. Further evaluation of PIFU in practice is needed before widespread implementation.


Assuntos
Ginecologia , Humanos , Feminino , Adulto , Pessoa de Meia-Idade , Inquéritos e Questionários , Satisfação do Paciente/estatística & dados numéricos , Atitude do Pessoal de Saúde , Adulto Jovem , Reino Unido , Idoso , Adolescente , Masculino
5.
Nano Lett ; 24(6): 1909-1915, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38315708

RESUMO

Coupling between molecular vibrations leads to collective vibrational states with spectral features sensitive to local molecular order. This provides spectroscopic access to the low-frequency intermolecular energy landscape. In its nanospectroscopic implementation, this technique of vibrational coupling nanocrystallography (VCNC) offers information on molecular disorder and domain formation with nanometer spatial resolution. However, deriving local molecular order relies on prior knowledge of the transition dipole magnitude and crystal structure of the underlying ordered phase. Here we develop a quantitative model for VCNC by relating nano-FTIR collective vibrational spectra to the molecular crystal structure from X-ray crystallography. We experimentally validate our approach at the example of a metal organic porphyrin complex with a carbonyl ligand as the probe vibration. This framework establishes VCNC as a powerful tool for measuring low-energy molecular interactions, wave function delocalization, nanoscale disorder, and domain formation in a wide range of molecular systems.

6.
Eur J Obstet Gynecol Reprod Biol ; 293: 72-77, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38118272

RESUMO

OBJECTIVE: The UK NHS Getting It Right First Time report (2021) recommended that a significant proportion of native tissue vaginal prolapse operations should be undertaken as day-case procedures (target: 80% anterior compartment, 70% posterior compartment, 60% combined anterior/posterior compartment). The evidence for perioperative care, options for anaesthesia and outcomes of day-case vaginal prolapse surgery is limited. This study aimed to establish current practice amongst UK gynaecologists and explore perceived barriers to implementing day-case surgery for pelvic organ prolapse. Study design A pre-tested 16-item survey was emailed to British Society of Urogynaecology members in July 2022. This survey recorded rates of day-case prolapse surgeries, barriers to implementation and practices for managing urethral catheters, vaginal packs, intraoperative anaesthetics and perioperative care. Responses to free-text questions were independently analysed by two of the authors and underwent thematic analysis. RESULTS: 121 eligible responses were received (28 % response-rate): 41 % never undertook day-case prolapse repair, 16 % undertook < 5 per year and 26 % undertook > 20 cases per year. There was no significant difference in training level or hospital setting between those groups. Reasons cited for not undertaking day-case prolapse surgery included concerns about vaginal packs and urinary catheters (92 %) postoperative complications (67 %), early discharge of elderly patients (60 %) and a lack of published evidence (39 %) or national guidance (35 %). For those currently undertaking day-case prolapse surgery; 67 % used general anaesthesia, 15 % spinal with short-acting local anaesthetic, 14 % spinal with long-acting local anaesthetic and 3 % local anaesthetic alone. Vaginal packs and self-retaining urethral catheters were used by 68 % and 70 % respectively. Concerns regarding the management of vaginal packs and urinary catheters were the most frequently cited barrier to implementing day-case surgery for pelvic organ prolapse amongst free-text responses. There were wide variations in managing catheters and packs, and in managing readmissions. CONCLUSIONS: There is significant variation in uptake and practice for day-case prolapse surgery in the UK, with legitimate clinical concerns a barrier to its implementation. Further evaluation and development of robust, evidence-based management pathways are required to make day-case prolapse surgery consistent, feasible and defensible in clinical practice.


Assuntos
Prolapso de Órgão Pélvico , Prolapso Uterino , Feminino , Humanos , Idoso , Prolapso Uterino/cirurgia , Anestésicos Locais , Motivação , Telas Cirúrgicas , Prolapso de Órgão Pélvico/cirurgia , Procedimentos Cirúrgicos em Ginecologia/métodos , Reino Unido
7.
Phys Chem Chem Phys ; 26(2): 1217-1224, 2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-38099737

RESUMO

Chemical vapor deposition (CVD) of group 4 metal-diboride ceramics from a single source is a versatile technique that finds many applications from hypersonic flight to microelectronics. Though the kinetics of CVD have been studied extensively-allowing significant process improvements-a mechanistic understanding of the process has yet to be attained. Computations suggest two plausible reaction pathways-one higher-energy and the second lower-that correlate well with experimental results reported in the literature, explaining phenomena such as high-temperature deposition resulting in films overstoichiometric in boron. These insights offer a new perspective that may be instrumental in the rational design of new precursors for single-source CVD.

9.
J Prim Care Community Health ; 14: 21501319231171519, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37148221

RESUMO

INTRODUCTION: Social determinants of health (SDoH) influence health outcomes and screening for health-related social needs (HRSN) is a recommended pediatric practice. In 2018, Denver Health and Hospitals (DH) implemented the Accountable Health Communities (AHC) model under the Centers for Medicare and Medicaid Services (CMS) and began using the AHC HRSN screening tool during selected well child visits (WCVs) at a DH Federally Qualified Health Center (FQHC). The current evaluation aimed to examine the program implementation and identify key lessons learned to inform the expansion of HRSN screening and referral to other populations and health systems. METHODS: Patients who completed a WCV between June 1, 2020 and December 31, 2021 (N = 13 750) were evaluated. Frequencies and proportions were used to describe patient characteristics of those that had a WCV, were screened, and received resource information. Multivariable logistic regression models with odds ratios (OR) and 95% confidence intervals (CI) were used to determine the association between patient characteristics and completing HRSN screening and provision of resource information. RESULTS: The screening tool was completed by 80% (n = 11 004) of caregivers bringing children to a WCV at the DH Westside Clinic, with over one-third (34.8%; n = 3830) reporting >1 social need. Food insecurity was the most common concern (22.3%; n = 2458). Non-English, non-Spanish (NENS) speakers were less likely to be screened (OR 0.43, 95% CI 0.33, 0.57) and less likely to report a social need (OR 0.59, 95% CI 0.42, 0.82) than speakers of English, after adjusting for age, race/ethnicity, and health insurance. CONCLUSIONS: A high rate of screening indicates feasibility of administering HRSN screenings for pediatric patients in a busy FQHC. More than a third of patients reported one or more social needs, underscoring the importance to identity these needs and the opportunity to offer personalized resources. Comparatively lower rates of screening and potential underreporting among NENS may be indicative of the availability and acceptability of current translation procedures as well as how the tool translates linguistically and culturally. Our experience highlights the need to partner with community organizations and involve patients and families to ensure SDoH screening and care navigation is part of culturally-appropriate patient-centered care.


Assuntos
Serviços de Saúde da Criança , Centros Comunitários de Saúde , Programas de Rastreamento , Avaliação das Necessidades , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Adulto Jovem , Serviços de Saúde da Criança/organização & administração , Colorado , Centros Comunitários de Saúde/organização & administração , Programas de Rastreamento/organização & administração , Programas de Rastreamento/estatística & dados numéricos , Determinantes Sociais da Saúde
10.
Inorg Chem ; 62(20): 7898-7905, 2023 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-37167020

RESUMO

Compounds with good photoluminescence quantum yields (ΦPL) in the deep-red to near-infrared parts of the spectrum are desired for a variety of applications in optoelectronics, imaging, and sensing. However, in this region of the spectrum, quantum yields are usually modest, which is explained by the energy gap law and the inherently slower radiative decay rates for low-energy emitters according to the second-order perturbation theory. In this work, we outline a new direction in deep-red luminescence, introducing a new suite of bis-cyclometalated iridium complexes with efficient luminescence beyond 650 nm. Seven new complexes are prepared using two different cyclometalating (C^N) ligands with four quinoline-derived ancillary ligands (L^X). The chosen cyclometalating ligands are well-established to produce deep-red phosphorescence and include a metalated phenyl ring appended to a conjugated heterocycle. The ancillary ligands combine a rigid quinoline or benzoquinoline "L" donor with a variable anionic "X" donor comprised of an O-donor aryloxy or carboxylate or an N-donor amidate. These complexes phosphoresce in the deep-red region with wavelengths between 650 and 700 nm and solution quantum yields between 0.018 and 0.42.

11.
Elife ; 122023 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-36688373

RESUMO

Individual sensory neurons can be tuned to many stimuli, each driving unique, stimulus-relevant behaviors, and the ability of multimodal nociceptor neurons to discriminate between potentially harmful and innocuous stimuli is broadly important for organismal survival. Moreover, disruptions in the capacity to differentiate between noxious and innocuous stimuli can result in neuropathic pain. Drosophila larval class III (CIII) neurons are peripheral noxious cold nociceptors and innocuous touch mechanosensors; high levels of activation drive cold-evoked contraction (CT) behavior, while low levels of activation result in a suite of touch-associated behaviors. However, it is unknown what molecular factors underlie CIII multimodality. Here, we show that the TMEM16/anoctamins subdued and white walker (wwk; CG15270) are required for cold-evoked CT, but not for touch-associated behavior, indicating a conserved role for anoctamins in nociception. We also evidence that CIII neurons make use of atypical depolarizing chloride currents to encode cold, and that overexpression of ncc69-a fly homologue of NKCC1-results in phenotypes consistent with neuropathic sensitization, including behavioral sensitization and neuronal hyperexcitability, making Drosophila CIII neurons a candidate system for future studies of the basic mechanisms underlying neuropathic pain.


Assuntos
Proteínas de Drosophila , Neuralgia , Animais , Drosophila/fisiologia , Cloretos , Proteínas de Drosophila/metabolismo , Nociceptividade/fisiologia , Nociceptores/fisiologia , Células Receptoras Sensoriais/fisiologia , Anoctaminas
12.
Health Inf Manag ; 52(2): 72-86, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-33016126

RESUMO

BACKGROUND: Patient involvement in decision-making plays a prominent role in improving the quality of healthcare. Despite this, shared decision-making is not routinely implemented. However, electronic assessment tools that capture patients' history, symptoms, opinions and values prior to their medical appointment are used by healthcare professionals during patient consultations to facilitate shared decision-making. OBJECTIVE: To assess the effectiveness of electronic assessment tools to improve the shared decision-making process. METHOD: A systematic review was conducted following PRISMA guidelines. Published literature was searched on MEDLINE, EMBASE and PsycINFO to identify potentially relevant studies. Data were extracted and analysed narratively. RESULTS: Seventeen articles, representing 4004 participants, were included in this review. The main findings were significant improvement in patient-provider communication and provider management of patient condition in the intervention group compared to the control group. In contrast, patient-provider satisfaction and time efficiency were assessed by relatively few included studies, and the effects of these outcomes were inconclusive. CONCLUSION: This review found that communication and healthcare professional's management of a patient's condition improves because of the use of electronic questionnaires. This is encouraging because the process of shared decision-making is reliant on high-quality communication between healthcare professionals and patients. IMPLICATIONS: We found that this intervention is especially important for people with chronic diseases, as they need to establish a long-term relationship with their healthcare provider and agree to a treatment plan that aligns with their values. More rigorous research with validated instruments is required.


Assuntos
Tomada de Decisão Compartilhada , Pessoal de Saúde , Participação do Paciente , Humanos
13.
Front Microbiol ; 13: 1033050, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36338061

RESUMO

Insufficient prey density is a major factor hindering the recovery of the Amur tiger (Panthera tigris altaica), and to effectively restore the Amur tiger, red deer (Cervus elaphus) was released into the Huangnihe National Nature Reserve of Northeast China as the main reinforcement. Differences in feeding and synergistic changes caused by the intestinal microbial communities could impact the adaptation of wildlife following reintroductions into field environments. We analyzed the foraging changes in shaping the intestinal microbial community of the red deer after being released to the Huangnihe National Nature Reserve and screened the key microbial flora of the red deer when processing complex food resources. The feeding and intestinal microbial communities of the red deer were analyzed by plant Deoxyribonucleic acid (DNA) barcoding sequencing and 16S rRNA high-throughput sequencing, respectively. The results showed that there were significant differences in food composition between wild and released groups [released in 2019 (R2): n = 5; released in 2021 (R0): n = 6]; the wild group fed mainly on Acer (31.8%) and Abies (25.6%), R2 fed mainly on Betula (44.6%), R0 had not formed a clear preferred feeding pattern but had certain abilities to process and adapt to natural foods. Firmicutes (77.47%) and Bacteroides (14.16%) constituted the main bacterial phylum of red deer, of which, the phylum Firmicutes was the key species of the introduced red deer for processing complex food resources (p < 0.05). The wild release process significantly changed the intestinal microbial structure of the red deer, making it integrate into the wild red deer. The period since release into the wild may be a key factor in reshaping the structure of the microbial community. This study suggested that the intestinal microbial structure of red deer was significantly different depending on how long since captive deer has been translocated. Individuals that have lived in similar environments for a long time will have similar gut microbes. This is the adaption process of the wildlife to natural environment after wild release, taking into account the gut microbes, and the feeding changes in shaping microbial communities can help introduced red deer match complex food resources and novel field environments.

14.
Sci Rep ; 12(1): 19734, 2022 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-36396677

RESUMO

Methods to probe and understand the dynamic response of materials following impulsive excitation are important for many fields, from materials and energy sciences to chemical and neuroscience. To design more efficient nano, energy, and quantum devices, new methods are needed to uncover the dominant excitations and reaction pathways. In this work, we implement a newly-developed superlet transform-a super-resolution time-frequency analytical method-to analyze and extract phonon dynamics in a laser-excited two-dimensional (2D) quantum material. This quasi-2D system, 1T-TaSe2, supports both equilibrium and metastable light-induced charge density wave (CDW) phases mediated by strongly coupled phonons. We compare the effectiveness of the superlet transform to standard time-frequency techniques. We find that the superlet transform is superior in both time and frequency resolution, and use it to observe and validate novel physics. In particular, we show fluence-dependent changes in the coupled dynamics of three phonon modes that are similar in frequency, including the CDW amplitude mode, that clearly demonstrate a change in the dominant charge-phonon couplings. More interestingly, the frequencies of the three phonon modes, including the strongly-coupled CDW amplitude mode, remain time- and fluence-independent, which is unusual compared to previously investigated materials. Our study opens a new avenue for capturing the coherent evolution and couplings of strongly-coupled materials and quantum systems.

15.
Chem Commun (Camb) ; 58(81): 11446-11449, 2022 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-36148809

RESUMO

Four new heteroleptic bis-chelate Cu(I) complexes showing panchromatic visible absorption are described here. With this heteroleptic design, we demonstrate that the energy levels of the spatially separated HOMO and LUMO can be independently and systematically controlled via ligand modification, with charge-transfer absorption bands throughout the visible and NIR regions that cover a wider range than typical Cu(I) chromophores.


Assuntos
Cobre , Ligantes
16.
Inorg Chem ; 61(41): 16317-16324, 2022 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-36179078

RESUMO

An (N-heterocyclic carbene)nickel(I) cation precursor reacts with the corresponding nickel(0) complex to form a dinickel(I,0) monocation. The Ni···Ni distance in this cation is 0.93 Å shorter than in the analogous dinickel(0) complex. Although the solid-state structure shows equivalent Ni centers, density functional theory calculations indicate significant electronic localization. Reactions with CO and NO form mononuclear carbonyl and nitrosyl complexes. Oxidative addition of an aryl bromide results in C-arylation of the carbene ligands.


Assuntos
Elétrons , Níquel , Brometos , Metano/análogos & derivados , Estrutura Molecular , Níquel/química
17.
Phys Rev E ; 105(5-1): 054141, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35706207

RESUMO

The motion of particles along channels of finite width is known to be hindered by either the presence of energy barriers along the channel direction or by variations in the width of the channel in the transverse direction (rugged channel). Remarkably, when both features are present, they can interact to produce a counterintuitive result: adding energy barriers to a rugged channel can enhance the rate of diffusion along it. This is the result of competing energetic and entropic effects. Under the approximation of particles instantaneously in equilibrium in the transverse direction, one can tailor the energy barriers to the ruggedness to recover free diffusion. However, such fine-tuning and potentially restrictive approximations are not necessary to observe an enhanced rate of diffusion as we demonstrate by adding a range of (non-fine-tuned) energy barriers to a channel of sinusoidally varying curvature. Furthermore, this was observed to hold for systems with a finite characteristic timescale for motion in the transverse direction, thus, suggesting that the phenomenon lends itself to be exploited for practical applications.

18.
Inorg Chem ; 61(3): 1228-1235, 2022 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-34982547

RESUMO

The syntheses and photophysical characterization of five new gold(I) complexes bearing diphenylamine-substituted fluorenyl moieties are reported; four are characterized by X-ray diffraction crystallography. Ancillary ligation on gold(I) is provided by organophosphine and N-heterocyclic carbene ligands. Two complexes, Au-DPA0 and Au-DPA1, are σ-aryls, two, Au-ADPA0 and Au-ADPA1, are σ-alkynyls, and one, Au-TDPA1, is a σ-triazolyl bound through carbon. All complexes show vibronically structured absorption and luminescence bands that are assignable to π-π* transitions localized on the diphenylamine-substituted fluorenyl π system. The excited-state dynamics of all five chromophores are governed by selection of the ancillary ligand and σ attachment of the diphenylamine-substituted fluorenyl moiety. All of these chromophores are dual luminescent in a toluene solution at 298 K. The luminescence from the aryl derivatives, Au-ADPA0 and Au-DPA1, appears green. The alkynyl derivative containing a phosphine ancillary ligand, Au-ADPA0, is a white-light emitter, while the alkynyl derivative containing an N-heterocyclic carbene ancillary ligand, Au-ADPA1, is a yellow-light emitter. The luminescence from the triazolyl-linked chromophore, Au-TDPA1, appears as yellow-green. Spin-restricted density functional theory calculations support the assignments of ligand-centric optical transitions but with contributions of ligand-to-metal charge transfer involving the vacant Au 6p orbital.

19.
Appl Opt ; 60(25): G199-G206, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34613208

RESUMO

We use the two-photon excited fluorescence method to determine the two-photon absorption (2PA) cross sections of three series of (fluorenyl benzothiazole) gold(I) complexes in the visible wavelength range from 570 to 700 nm. We compare the effect of ancillary ligand substitutions on the 2PA magnitudes and find that the ancillary ligand does not drastically affect either the magnitude or the shape of 2PA. Even so, moderate 2PA cross sections were measured that ranged from 10 to 1000 s of GM (Göppert-Mayer, =10-50cm4s/photon), making these types of complexes nonlinear optical materials for two-photon absorbing applications.

20.
iScience ; 24(6): 102657, 2021 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-34151240

RESUMO

Low temperatures can be fatal to insects, but many species have evolved the ability to cold acclimate, thereby increasing their cold tolerance. It has been previously shown that Drosophila melanogaster larvae perform cold-evoked behaviors under the control of noxious cold-sensing neurons (nociceptors), but it is unknown how the nervous system might participate in cold tolerance. Herein, we describe cold-nociceptive behavior among 11 drosophilid species; we find that the predominant cold-evoked larval response is a head-to-tail contraction behavior, which is likely inherited from a common ancestor, but is unlikely to be protective. We therefore tested the hypothesis that cold nociception functions to protect larvae by triggering cold acclimation. We found that Drosophila melanogaster Class III nociceptors are sensitized by and critical to cold acclimation and that cold acclimation can be optogenetically evoked, sans cold. Collectively, these findings demonstrate that cold nociception constitutes a peripheral neural basis for Drosophila larval cold acclimation.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA