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1.
ACS Nano ; 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38951541

RESUMEN

Terbium-doped gadolinium oxysulfide (Gd2O2S:Tb3+), commonly referred to as Gadox, is a widely used scintillator material due to its exceptional X-ray attenuation efficiency and high light yield. However, Gadox-based scintillators suffer from low X-ray spatial resolution due to their large particle size, which causes significant light scattering. To address this limitation, we report the synthesis of terbium-doped colloidal Gadox nanoplatelets (NPLs) with near-unity photoluminescence quantum yield (PLQY) and high radioluminescence light yield (LY). In particular, our investigation reveals a strong correlation between PLQY, LY, particle size, and Tb3+concentration. Our synthetic approach allows precise control over the lateral size and thickness of the Gadox NPLs, resulting in a LY of 50,000 photons/MeV. Flexible scintillating screens fabricated with the solution-processable Gadox NPLs exhibited a 20 lp/mm X-ray spatial resolution, surpassing commercial Gadox scintillators. These high-performance and flexible Gadox NPL-based scintillators enable enhanced X-ray imaging capabilities in medicine and security. Our work provides a framework for designing nanomaterial scintillators with superior spatial resolution and efficiency through precise control of dimensions and dopant concentration.

2.
Int Urol Nephrol ; 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38879693

RESUMEN

BACKGROUND: Traditional open orchiopexy remains the standard treatment for palpable undescended testicles (UDT). However, laparoscopic orchiopexy has recently gained attention as an alternative approach. AIM AND OBJECTIVES: This study aimed to compare the outcomes of laparoscopic versus open orchiopexy for high-inguinal undescended testes. SUBJECTS AND METHODS: A prospective randomized comparative study was conducted, involving 208 children with high inguinal undescended testes. The patients were divided into two groups: group A (104 patients) underwent laparoscopic orchiopexy and group B (104 patients) underwent open orchiopexy. RESULTS: There was a significant difference in the final testicular position between the two groups. The follow-up after 1 year showed that 100% of patients in group A had a lower testicular position, compared to 72.6% in group B. Laparoscopic orchiopexy demonstrated better outcomes in terms of achieving a lower testicular position. CONCLUSION: Both Laparoscopic and Open Orchiopexy are safe and effective for the treatment of high inguinal undescended testes. However, Laparoscopic Orchiopexy was superior to Open Orchiopexy because it was associated with better outcomes with regard to the final testicular position at the bottom of the scrotum or at a lower level below the mid-scrotal point.

3.
ACS Photonics ; 11(6): 2273-2281, 2024 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-38911840

RESUMEN

Using ultrafast broad-band transient absorption (TA) spectroscopy of photoexcited MAPbBr3 thin films with probe continua in the visible and the mid- to deep-ultraviolet (UV) ranges, we capture the ultrafast renormalization at the fundamental gap at the R symmetry point of the Brillouin zone (BZ) and a higher energy gap at the M symmetry point. Advanced global lifetime analysis and lifetime density distribution analysis are applied to extract quantitative information. Our work confirms the similarity of the response at both high-symmetry points, which indicates a band edge renormalization that rises within the instrument response function (IRF, ∼250 fs) and decays in ca. 400-600 fs, undergoing an energy red shift of 90-150 meV. The reported time scale corresponds to the decay of free carriers into neutral excitons. The ability to monitor different high-symmetry points in photoexcited perovskites opens exciting prospects for the characterization of a large class of materials and for photonic applications.

4.
Inorg Chem ; 63(25): 11583-11591, 2024 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-38857486

RESUMEN

Conjugated molecules with donor-acceptor-donor (D-A-D) moieties have garnered significant attention for their ability to form luminescent metal-organic frameworks (LMOFs). D-A-D molecules feature tunable bandgaps, which can be varied systematically to control the fluorescence wavelength of LMOFs. In this study, we prepared and characterized the fluorescence properties of two porous interpenetrated Zr-organic frameworks (PIZOFs) constructed using 4,4'-(benzo[c][1,2,5]selenadiazole-4,7-diylbis(ethyne-2,1-diyl))dibenzoic acid (L-Se) or 4,4'-(benzo[c][1,2,5]thiadiazole-4,7-diylbis(ethyne-2,1-diyl))dibenzoic acid (L-S) as linkers. The corresponding MOFs are denoted as PIZOF-Se and PIZOF-S, respectively. Through our investigation, we explored the correlation between the structure of the frameworks and their respective optical properties. Our findings revealed that there are distinct differences in the fluorescence properties of the two PIZOFs. Specifically, the fluorescence of PIZOF-S is red-shifted from that characteristic of the corresponding linker, L-S. By contrast, the fluorescence of PIZOF-Se is substantially blue-shifted from that of linker L-Se. The emission of mixed-linker MOFs is explored by combining L-S or L-Se with structurally analogous, but nonfluorescent linker, 4,4'-((perfluoro-1,4-phenylene)bis(ethyne-2,1-diyl))dibenzoic acid (L-F). Based on steady-state and time-resolved photoluminescence experiments, as well as confocal fluorescence microscopy combined with fluorescence lifetime imaging (FILM), we demonstrated that linker engineering is an effective method to tune the emission behavior of LMOFs.

5.
BMC Oral Health ; 24(1): 666, 2024 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-38849827

RESUMEN

AIM: To assess the efficacy of positional therapy and oral appliance therapy for the management of positional obstructive sleep apnea. METHODS: We searched PubMed, Web of Science, Cochrane, and SCOPUS for relevant clinical trials. Quality assessment of the included trials was evaluated according to Cochrane's risk of bias tool. We included the following outcomes: The apnea-hypopnea index (AHI), AHI non-supine, AHI supine, sleep efficiency, percentage of supine sleep, Adherence (≥ 4 h/night, ≥ 5 days/week), Oxygen desaturation Index, Arousal Index, Epworth Sleepiness Scale score (ESS), Mean SpO2, and Functional Outcomes of Sleep Questionnaire. RESULTS: The AHI non-supine and the ESS scores were significantly lower in the OAT cohort than in the PT cohort. The PT cohort was associated with a significantly decreased percentage of supine sleep than the OAT cohort (MD= -26.07 [-33.15, -19.00], P = 0.0001). There was no significant variation between PT cohort and OAT cohort regarding total AHI, AHI supine, ODI, sleep efficiency, arousal index, FOSQ, adherence, and mean SpO2. CONCLUSION: Both Positional Therapy and Oral Appliance Therapy effectively addressed Obstructive Sleep Apnea. However, Oral Appliance Therapy exhibited higher efficiency, leading to increased supine sleep percentage and more significant reductions in the Apnea Hypopnea Index during non-supine positions, as well as lower scores on the Epworth Sleepiness Scale.


Asunto(s)
Ensayos Clínicos Controlados Aleatorios como Asunto , Apnea Obstructiva del Sueño , Apnea Obstructiva del Sueño/terapia , Humanos , Posición Supina , Posicionamiento del Paciente/métodos
6.
J Med Life ; 17(1): 99-108, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38737659

RESUMEN

Neuro-ophthalmic disorders are often documented individually for each illness, with little data available on their overall incidence and pattern. The overall incidence of neuro-ophthalmic illnesses in Iraq is still not recorded. This study aimed to evaluate the clinical, demographic, and etiological features of patients seeking consultation at an Iraqi neuro-ophthalmology clinic. A prospective cross-sectional observational research was conducted at the Janna Ophthalmic Center in Baghdad, Iraq. The center serves a diverse patient population from various governorates. All newly diagnosed patients with neuro-ophthalmic disorders who visited the neuro-ophthalmological clinic, regardless of gender or age group, were included. The neuro-ophthalmologist established a diagnosis for each case by reviewing the patient's medical history, doing physical examinations, administering specific tests, and, in certain cases, using neuroimaging methods. The duration of the study was extended from March 2021 to November 2022. Among the 6440 patients evaluated, 613 cases were confirmed at the neuro-ophthalmology clinic. Ischemic optic neuropathy (NAION, AION, and PION) was the most prevalent diagnosis, accounting for 17.61% of newly reported cases in the field of neuro-ophthalmology. This was followed by sixth nerve palsy. Diabetes mellitus affected 42.7% of the cases, followed by hypertension, which affected 39.3% of the participants. The incidence of neuro-ophthalmic diseases tended to be high. Ischemic optic neuropathy and sixth nerve palsy, traumatic/compressive optic neuropathy, and papilledema were the most common neuro-ophthalmic disorders reported.


Asunto(s)
Oftalmopatías , Humanos , Irak/epidemiología , Femenino , Masculino , Adulto , Estudios Transversales , Estudios Prospectivos , Oftalmopatías/epidemiología , Persona de Mediana Edad , Adolescente , Adulto Joven , Niño , Anciano , Oftalmología , Incidencia , Preescolar
7.
J Multidiscip Healthc ; 17: 1971-1979, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38706504

RESUMEN

Purpose: Older persons are frequently prescribed several medications; therefore, inappropriate medication prescriptions are common. Prescribing potentially inappropriate medications (PIMs) poses a serious risk and hence, we aimed to assess the PIMs in older patients in Tabuk, using the 2023 Beers criteria. Patients and Methods: A retrospective cross-sectional study was carried out, including older persons ≥65 years of age admitted in two government hospitals from June 2022 to May 2023, and prescribed with five or more medications. PIMs were assessed using the 2023 Beers criteria. Descriptive analysis was performed for the categorical and continuous variables. Logistic regression was used to assess the influence of age, gender, number of medications and comorbidities on PIMs using SPSS version 27. Results: The study included 420 patients. The mean age of the participants was 75.52 ± 8.70 years (range, 65-105 years). There was a slightly higher proportion of females (52%). The prevalence of PIMs was 81.43%, where 35.41% were prescribed one PIM, 26.48% were prescribed two PIMs, and 17.32% were prescribed three PIMs. The proportion of medications considered potentially inappropriate among older patients was 70.11%, and proton pump inhibitors were the most commonly prescribed medication (52.99%). The proportion of medications to be used with caution was 19.55%, with diuretics being the most frequently administered medication (91.43%). Gender and comorbidity did not influence PIMs, but age and number of medications significantly influenced the likelihood of PIMs. Conclusion: PIMs are prevalent among older people and are significantly associated with age and multiple medications. Caution should be exercised while prescribing medications to older persons. Frequent audits should be performed to assess PIMs, and clinicians should be informed of the same to avoid serious outcomes associated with PIMs. Interventions designed to reduce PIM need to be initiated.

8.
Cureus ; 16(4): e58330, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38752082

RESUMEN

Background Teledentistry, a subspecialty of telemedicine dedicated to dentistry, has shown promise in improving access to dental care, particularly in rural and isolated areas. It integrates digital and telecommunication technology with dentistry, allowing for the remote distance exchange of relevant clinical information and digital dental imaging for dental consultation and treatment planning. Periodontal disease diagnosis is crucial for effective treatment and prevention of irreversible loss of periodontal structures. Early identification of periodontal disease can be pivotal in preventing periodontal tissue destruction and tooth loss and improving the overall quality of patients' lives. Sebha is a city located in the Fezzan region of southwestern Libya. It is the capital of the Sabha District and the Sabha Governorate. The city is situated in the Libyan part of the Sahara desert and is known for its strategic location as a gateway to the Sahara desert. However, there is a lack of information on the use of teledentistry in Libya in general and the use of teleperiodontics, especially in periodontal diagnosis. Hence, the aim of this questionnaire study was to evaluate knowledge, attitudes, and practice of teledentistry among dental interns at Sebha, Libya. Materials and methods A paper-based questionnaire consisting of 28 close­ended Likert scale questions, including sections assessing the knowledge, attitude, and practice of teledentistry and teleperiodontics, was administered to dental interns at the Faculty of Dentistry, Sebha University, Sebha, Libya. Results The study surveyed 42 dental interns of the Faculty of Sebha, Libya, in total, with an 82.35% response rate among them. The majority of participants (59.5%) felt that teledentistry is reliable in arriving at periodontal diagnosis. The majority of participants (64.3%%) also had acceptable levels of trust in teledentistry equipment. However, over 45% percent of dental practitioners voiced their worries about patient privacy. Most of the participants suggested using teledentistry in some form in their future practice. Conclusion Teledentistry and its branch teleperiodontics are recent developments and its penetration among dental healthcare workers, and their knowledge, attitude, and practice remain to be thoroughly understood. The changing trends in attitudes and practice as a consequence of changes in Internet and technological awareness and the effects of the pandemic warrant closer observation and study.

9.
World J Gastrointest Endosc ; 16(5): 227-231, 2024 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-38813578

RESUMEN

Common bile duct (CBD) stones are a common biliary tract disease. For asymptomatic CBD stones, stone removal by endoscopic retrograde cholangiopancreatography (ERCP) is recommended in available guidelines. Because asymptomatic CBD stones is a benign disease with no noticeable symptoms, the risk vs benefit strategy should be thoroughly considered before performing ERCP in these patients. Clinical care review, technical aspects of the procedure, and patient preferences should also be considered.

10.
Heliyon ; 10(7): e29335, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38623245

RESUMEN

Background: Diarrhea is a leading cause of illness and mortality among children under five, posing a significant public health challenge in Malawi. The current study assesses the prevalence and risk factors linked to diarrhea among under-five children in Malawi. Method: The researcher used the Malawi Multiple Indicator Cluster Survey (MICS) 2019-20 as the dataset for this study. Due to the complex sampling design, survey logistic regression was used to accomplish the study objectives. The sample size was 15569 children who were aged under five. Results: The study found that the prevalence of diarrhea was 24.9%, with a higher percentage observed among children aged 12-23 months (38.5%) compared to other age groups. Additionally, children from the southern region had a higher prevalence of diarrhea at 27% compared to those from the northern region at 19.3%. Children from the poorest households also had a higher prevalence of diarrhea at 28.9% compared to those from the richest households at 22.6%. Furthermore, children with fever had a higher prevalence of diarrhea at 33.3% compared to those who did not have fever at 19.4%. Conclusion: The current study concluded that the prevalence of diarrhea was higher among children aged 12-23 months. Subsequently, policymakers should apply policies to reduce this high prevalence among this age group of children. In addition, the government needs special consideration in diarrhea control for children from the southern region because of the high prevalence of the disease compared to the other regions in Malawi. My study can help policymakers understand the scope and nature of the problem, which can notify the development of policies and programs intended to decrease the prevalence of risk factors and enhance child health outcomes.

11.
Artículo en Inglés | MEDLINE | ID: mdl-38573046

RESUMEN

Tracking the dynamics of ultrafast hole injection into copper thiocyanate (CuSCN) at the interface can be experimentally challenging. These challenges include restrictions in accessing the ultraviolet spectral range through transient electronic spectroscopy, where the absorption spectrum of CuSCN is located. Time-resolved vibrational spectroscopy solves this problem by tracking marker modes at specific frequencies and allowing direct access to dynamical information at the molecular level at donor-acceptor interfaces in real time. This study uses photoabsorber PM6 (poly[(2,6-(4,8-bis(5-(2-ethylhexyl-3-fluoro)thiophen-2-yl)-benzo[1,2-b:4,5-b']dithiophene))-alt-(5,5-(1',3'-di-2-thienyl-5',7'-bis(2-ethylhexyl)-benzo[1',2'-c:4',5'-c']dithiophene-4,8-dione))]) as a model system to explore and decipher the hole transfer dynamics of CuSCN using femtosecond (fs) mid-infrared (IR) spectroscopy. The time-resolved results indicate that excited PM6 exhibits a sharp vibrational mode at 1599 cm-1 attributed to the carbonyl group, matching the predicted frequency position obtained from time-dependent density functional theory (DFT) calculations. The fs mid-IR spectroscopy demonstrates a fast formation (<168 fs) and blue spectral shift of the CN stretching vibration from 2118 cm-1 for CuSCN alone to 2180 cm-1 for PM6/CuSCN, confirming the hole transfer from PM6 to CuSCN. The short interfacial distance and high frontier orbital delocalization obtained from the interfacial DFT models support a coherent and ultrafast regime for hole transfer. These results provide direct evidence for hole injection at the interface of CuSCN for the first time using femtosecond mid-IR spectroscopy and serve as a new investigative approach for interfacial chemistry and solar cell communities.

12.
Appl Neuropsychol Child ; : 1-8, 2024 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-38452103

RESUMEN

The present study aimed to identify autistic traits as a mediator between visual working memory capacity and enhanced performance in visual-perceptual tasks in children with ASD. One hundred-forty children, ages 4-6 years, participated in this study (mean age = 5.34 ± 4.11, 98 males). They were recruited from Taiba Specialized Centers for the Care of People with Special Needs in Saudi Arabia. A correlational design was used to identify the mediating role of autistic traits in the relationship between visual working memory capacity and enhanced performance in visual-perceptual tasks in children with ASD. The present study developed a theoretical model that incorporated autistic traits as a mediator between visual working memory capacity and enhanced performance in visual-perceptual tasks in children with ASD. The study findings indicate that: (1) A significant positive correlation exists between autistic traits and visual working memory capacity; (2) A significant positive correlation exists between autistic traits and enhanced performance in visual-perceptual tasks; (3) The relationship between visual working memory capacity and enhanced performance is mediated by autistic traits.

13.
J Phys Chem Lett ; 15(11): 2988-2994, 2024 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-38457267

RESUMEN

Intermolecular charge transfer (CT) complexes have emerged as versatile platforms with customizable optical properties that play a pivotal role in achieving tunable photoresponsive materials. In this study, we introduce an innovative approach for enhancing the modulation bandwidth and net data rates in optical wireless communications (OWCs) by manipulating combinations of monomeric molecules within intermolecular CT complexes. Concurrently, we extensively investigate the intermolecular charge transfer mechanism through diverse steady-state and ultrafast time-resolved spectral techniques in the mid-infrared range complemented by theoretical calculations using density functional theory. These intermolecular CT complexes empower precise control over the -3 dB bandwidth and net data rates in OWC applications. The resulting color converters exhibit promising performance, achieving a net data rate of ∼100 Mb/s, outperforming conventional materials commonly used in the manufacture of OWC devices. This research underscores the substantial potential of engineering intermolecular charge transfer complexes as an ongoing progression and commercialization within the OWC. This carries profound implications for future initiatives in high-speed and secure data transmission, paving the way for promising endeavors in this area.

14.
Front Oncol ; 14: 1341794, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38515575

RESUMEN

Background: Large cell neuroendocrine carcinoma (LCNEC) is a rare subtype of prostate cancer. The pathogenesis, clinical manifestation, treatment options, and prognosis are uncertain and underreported. Materials and methods: A systematic search was conducted in April 2022 through PubMed, Embase, and Cochrane. We reviewed cases of LCNEC developed either from de novo or transformation from prostate adenocarcinoma and summarized the relevant pathophysiological course, treatment options, and outcomes. Results: A total of 25 patients with a mean age of 70.4 (range 43 87 years old) from 18 studies were included in this review. 13 patients were diagnosed with de novo LCNEC of the prostate. 12 patients were from the transformation of adenocarcinoma post-hormonal therapy treatment. Upon initial diagnosis, patients diagnosed with de novo prostatic LCNEC had a mean serum PSA value of 24.6 ng/ml (range: 0.09-170 ng/ml, median 5.5 ng/ml), while transformation cases were significantly lower at 3.3 ng/ml (range: 0-9.3 ng/ml, median 0.05 ng/ml). The pattern of metastasis closely resembles prostate adenocarcinoma. Six out of twenty-three cases displayed brain metastasis matching the correlation between neuroendocrine tumors and brain metastasis. Three notable paraneoplastic syndromes included Cushings syndrome, dermatomyositis, and polycythemia. Most patients with advanced metastatic disease received conventional platinum-based chemotherapy with a mean survival of 5 months. There was one exception in the transformation cohort with a somatic BRCA2 mutation who was treated with a combination of M6620 and platinum-based chemotherapy with an impressive PFS of 20 months. Patients with pure LCNEC phenotype have worse survival outcomes when compared to those with mixed LCNEC and adenocarcinoma phenotypes. It is unclear whether there is a survival benefit to administering ADT in pure pathologies. Conclusion: LCNEC of the prostate is a rare disease that can occur de novo or transformation from prostatic adenocarcinoma. Most patients present at an advanced stage with poor prognosis and are treated with conventional chemotherapy regimens. Patients who had better outcomes were those who were diagnosed at an early stage and received treatment with surgery or radiation and androgen deprivation therapy (ADT). There was one case with an exceptional outcome that included a treatment regimen of M6620 and chemotherapy.

15.
J Am Chem Soc ; 146(11): 7373-7385, 2024 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-38433410

RESUMEN

Organic-inorganic atomically precise nanoclusters provide indispensable building blocks for establishing structure-property links in hybrid condensed matter. However, robust glasses of ligand-protected nanocluster solids have yet to be demonstrated. Herein, we show [Cu4I4(PR3)4] cubane nanoclusters coordinated by phosphine ligands (PR3) form robust melt-quenched glasses in air with reversible crystal-liquid-glass transitions. Protective phosphine ligands critically influence the glass formation mechanism, modulating the glasses' physical properties. A hybrid glass utilizing ethyldiphenylphosphine-based nanoclusters, [Cu4I4(PPh2Et)4], exhibits superb optical properties, including >90% transmission in both visible and near-infrared wavelengths, negligible self-absorption, near-unity quantum yield, and high light yield. Experimental and theoretical analyses demonstrate the structural integrity of the [Cu4I4(PPh2Et)4] nanocluster, i.e., iodine-bridged tetranuclear cubane, has been fully preserved in the glass state. The strong internanocluster CH-π interactions found in the [Cu4I4(PPh2Et)4] glass and subsequently reduced structural vibration account for its enhanced luminescence properties. Moreover, this highly transparent glass enables performant X-ray imaging and low-loss waveguiding in fibers drawn above the glass transition. The discovery of "nanocluster glass" opens avenues for unraveling glass formation mechanisms and designing novel luminescent glasses of well-defined building blocks for advanced photonics.

16.
Mater Horiz ; 11(10): 2494-2505, 2024 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-38477151

RESUMEN

Atomically precise copper nanoclusters (NCs) are an emerging class of nanomaterials for catalysis. Their versatile core-shell architecture opens the possibility of tailoring their catalytically active sites. Here, we introduce a core-shell copper nanocluster (CuNC), [Cu29(StBu)13Cl5(PPh3)4H10]tBuSO3 (StBu: tert-butylthiol; PPh3: triphenylphosphine), Cu29NC, with multiple accessible active sites on its shell. We show that this nanocluster is a versatile catalyst for C-heteroatom bond formation (C-O, C-N, and C-S) with several advantages over previous Cu systems. When supported, the cluster can also be reused as a heterogeneous catalyst without losing its efficiency, making it a hybrid homogeneous and heterogeneous catalyst. We elucidated the atomic-level mechanism of the catalysis using density functional theory (DFT) calculations based on the single crystal structure. We found that the cooperative action of multiple neighboring active sites is essential for the catalyst's efficiency. The calculations also revealed that oxidative addition is the rate-limiting step that is facilitated by the neighboring active sites of the Cu29NC, which highlights a unique advantage of nanoclusters over traditional copper catalysts. Our results demonstrate the potential of nanoclusters for enabling the rational atomically precise design and investigation of multi-site catalysts.

17.
J Am Chem Soc ; 146(6): 4144-4152, 2024 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-38315569

RESUMEN

Circularly polarized light-emitting diodes (CP-LEDs) are critical for next-generation optical technologies, ranging from holography to quantum information processing. Currently deployed chiral luminescent materials, with their intricate synthesis and processing and limited efficiency, are the main bottleneck for CP-LEDs. Chiral metal nanoclusters (MNCs) are potential CP-LED materials, given their ease of synthesis and processability as well as diverse structures and excited states. However, their films are usually plagued by inferior electronic quality and aggregation-caused photoluminescence quenching, necessitating their incorporation into host materials; without such a scheme, MNC-based LEDs exhibit external quantum efficiencies (EQEs) < 10%. Herein, we achieve an efficiency leap for both CP-LEDs and cluster-based LEDs by using novel chiral MNCs with aggregation-induced emission enhancement. CP-LEDs using enantiopure MNC films attain EQEs of up to 23.5%. Furthermore, by incorporating host materials, the devices yield record EQEs of up to 36.5% for both CP-LEDs and cluster-based LEDs, along with electroluminescence dissymmetry factors (|gEL|) of around 1.0 × 10-3. These findings open a new avenue for advancing chiral light sources for next-generation optoelectronics.

18.
J Am Chem Soc ; 146(8): 5393-5401, 2024 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-38359303

RESUMEN

Disentangling electronic and thermal effects in photoexcited perovskite materials is crucial for photovoltaic and optoelectronic applications but remains a challenge due to their intertwined nature in both the time and energy domains. In this study, we employed temperature-dependent variable-angle spectroscopic ellipsometry, density functional theory calculations, and broadband transient absorption spectroscopy spanning the visible to mid-to-deep-ultraviolet (UV) ranges on MAPbBr3 thin films. The use of deep-UV detection opens a new spectral window that enables the exploration of high-energy excitations at various symmetry points within the Brillouin zone, facilitating an understanding of the ultrafast responses of the UV bands and the underlying mechanisms governing them. Our investigation reveals that the photoinduced spectral features remarkably resemble those generated by pure lattice heating, and we disentangle the relative thermal and electronic contributions and their evolutions at different delay times using combinations of decay-associated spectra and temperature-induced differential absorption. The results demonstrate that the photoinduced transients possess a significant thermal origin and cannot be attributed solely to electronic effects. Following photoexcitation, as carriers (electrons and holes) transfer their energy to the lattice, the thermal contribution increases from ∼15% at 1 ps to ∼55% at 500 ps and subsequently decreases to ∼35-50% at 1 ns. These findings elucidate the intricate energy exchange between charge carriers and the lattice in photoexcited perovskite materials and provide insights into the limited utilization efficiency of photogenerated charge carriers.

19.
Adv Mater ; 36(21): e2312053, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38340045

RESUMEN

The exacerbation of inherent light scattering with increasing scintillator thickness poses a major challenge for balancing the thickness-dependent spatial resolution and scintillation brightness in X-ray imaging scintillators. Herein, a thick pixelated needle-like array scintillator capable of micrometer resolution is fabricated via waveguide structure engineering. Specifically, this involves integrating a straightforward low-temperature melting process of manganese halide with an aluminum-clad capillary template. In this waveguide structure, the oriented scintillation photons propagate along the well-aligned scintillator and are confined within individual pixels by the aluminum reflective cladding, as substantiated from the comprehensive analysis including laser diffraction experiments. Consequently, thanks to isolated light-crosstalk channels and robust light output due to increased thickness, ultrahigh spatial resolutions of 60.8 and 51.7 lp mm-1 at a modulation transfer function (MTF) of 0.2 are achieved on 0.5 mm and even 1 mm thick scintillators, respectively, which both exceed the pore diameter of the capillary arrays' template (Φ = 10 µm). As far as it is known, these micrometer resolutions are among the highest reported metal halide scintillators and are never demonstrated on such thick scintillators. Here an avenue is presented to the demand for thick scintillators in high-resolution X-ray imaging across diverse scientific and practical fields.

20.
J Cardiovasc Magn Reson ; 26(1): 100007, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38211509

RESUMEN

"Cases of SCMR" is a case series on the SCMR website (https://www.scmr.org) for the purpose of education. The cases reflect the clinical presentation, and the use of cardiovascular magnetic resonance (CMR) in the diagnosis and management of cardiovascular disease. The 2022 digital collection of cases are presented in this manuscript.


Asunto(s)
Enfermedades Cardiovasculares , Valor Predictivo de las Pruebas , Humanos , Enfermedades Cardiovasculares/diagnóstico por imagen , Enfermedades Cardiovasculares/terapia , Persona de Mediana Edad , Femenino , Masculino , Anciano , Imagen por Resonancia Magnética , Adulto , Pronóstico , Adulto Joven
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