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Significant efforts are dedicated to developing new classes of organic semiconductor materials to achieve electrically pumped lasing. However, further advancements are necessary to understand the relationship between the structure and property for the creation of innovative laser materials with high stability, low triplet yield, ultra-low lasing threshold, and low-efficiency roll-off at ultra-bright electroluminescence. Here, a new design principle is validated for organic semiconductor laser materials, demonstrating simultaneous enhancement in the key figures of merit of low amplified spontaneous emission thresholds (E th ), efficient electroluminescence, and low triplet yields. By applying the Einstein stimulated emission rate equation and Strickler-Berg approximation, Two red-emitting laser dimers of Cibalackrot with different linkers are constructed, leading to giant enhancement (≈250%) in oscillator strengths, and stimulated emission cross-sections. When blended in poly(9,9-dioctylfluorene-alt-benzothiadiazole), the new dimers achieve an ultra-low E th (4.5 ± 0.3 µJ cm -2 ) in the deep red region (λ ASE  = 655 nm), among the lowest reported for deep-red emitters. Organic light-emitting diodes (OLEDs) utilizing the dimer blend exhibit low-efficiency roll-off under DC mode. Under pulse operation, the OLEDs achieve high current densities (90 A m -2 ) and ultrahigh brightness (≈710 000 cd m -2 ). These findings highlight the dimerization design as an excellent platform to advance organic semiconductor laser materials., (© 2024 Wiley‐VCH GmbH.)

Organic lasers have attracted increasing attention owing to their superior characteristics such as lightweight, low-cost manufacturing, high mechanical flexibility, and high emission-wavelength tunability. Recent breakthroughs include electrically pumped organic laser diodes and an electrically driven organic laser, integrated with an organic light-emitting diode pumping. However, the availability of efficient deep blue organic laser chromophores remains limited. In this study, we develop two novel rigid oligophenylenes, end-capped with carbazole and phenylcarbazole groups, to demonstrate exceptional optical and amplified spontaneous emission (ASE) properties. These oligophenylenes are not only solution processable but also exhibit remarkably high solution photoluminescence quantum yields (PLQYs) of 90% and high radiative rates of 1.35 × 10 9 s -1 in the deep blue range. Our theoretical calculations confirm that the carbazole and phenylcarbazole end groups play a pivotal role in enhancing the optical transitions of the oligophenylene laser chromophores, thereby elevating their emission oscillator strengths. Remarkably, these materials demonstrate low solid-state ASE threshold values of 1.0 and 1.5 μJ/cm 2 (at 431 and 418 nm, respectively). To the best of our knowledge, these ASE thresholds represent the lowest reported at these specific ASE wavelengths in the literature, regardless of whether they are solution-processed or thermally evaporated films. Furthermore, they exhibit excellent thermal and photostability, low triplet quantum yields, as well as negligible overlap of excited-state absorption within the ASE emission region, making them excellent candidates for a new class of deep blue materials for organic lasers. By integrating insights from theoretical calculations and experimental validation, our study provides a comprehensive understanding of the design principles behind these high-performing organic laser chromophores, paving the way for the development of advanced organic lasers with enhanced performance characteristics.

Introduction: Even brief episodes of fecal contamination of drinking water can lead directly to illness in the consumers. In water-borne outbreaks, the connection between poor microbial water quality and disease can be quickly identified. The impact of non-compliant drinking water samples due to E. coli taken for regular monitoring on the incidence of notified acute gastrointestinal infections has not yet been studied., Methods: The objective of this study was to analyse the geographical distribution of notified acute gastrointestinal infections (AGI) in Slovenia in 2010, with hotspot identification. The second aim of the study was to correlate the fecal contamination of water supply system on the settlement level with the distribution of notified AGI cases. Spatial analysis using geo-information technology and other methods were used., Results: Hot spots with the highest proportion of notified AGI cases were mainly identified in areas with small supply zones. The risk for getting AGI was drinking water contaminated with E. coli from supply zones with 50-1000 users: RR was 1.25 and significantly greater than one (p-value less than 0.001)., Conclusion: This study showed the correlation between the frequency of notified AGI cases and non-compliant results in drinking water monitoring.

Objective: To assess provider and client acceptance of health department-delivered HIV partner services (PS) delivered in clinical and community settings., Methods: In 2006, New York city (NYC) formed the HIV field services unit (FSU), staffed with experienced sexually transmitted disease intervention specialists (DIS). DIS were stationed at 8 large hospitals to assist clinical providers and their HIV-positive patients with PS in areas with high rates of delayed HIV diagnoses and HIV-related mortality. We surveyed providers (self-administered questionnaire) and clients (staff-administered) to examine provider and patients as well as patients' HIV-exposed partners' acceptance of and concerns regarding PS., Results: Response rates were as follows: 63% (132/211) providers; 90% (492/544) patients who accepted PS; 73% (16/22) patients who declined PS; 83% (139/168) partners who received notification; and 81% (25/31) partners who declined notification. Most providers felt the DIS focus and expert skills in PS was beneficial to providers (87%) and clients (89%). Most patients (91%) had a positive or neutral attitude about the health department-delivered PS. Most providers reported no disadvantage to DIS providing PS (69%); their most commonly cited (24%) concern was potential patient confusion about the roles of providers versus DIS. Patients' most common concerns were the intrusive nature of the interviews and the length of the interview (50/492, 20%). The partners wanted to know who named them (32/139, 23%)., Conclusions: Health department-delivered PS by DIS in clinical and community settings was acceptable to providers, HIV-infected patients, and HIV-exposed partners. Overall, our survey showed strong provider and client support for this approach.

Two elderly patients suffering from a dementing illness are described. The patients manifested homicidal behaviour in association with dementia. Possible risk factors for such behaviour are explored. Implications arising from the cases are discussed.