Rapid Transit Research Articles

Additional criteria on scintigraphic testing for diagnosis of rapid colonic transit in patients with chronic diarrhea.

Colonic transit (CT) measured by validated scintigraphy using 111In-labeled activated charcoal particles is summarized using geometric center (GC) of isotopic distribution in four colonic regions and stool at 24 and 48 h. Diagnosis of rapid CT is currently based on GC24 ≥4.4 in females and >4.7 in males, which lack sensitivity. Our aim was to evaluate, in patients with chronic diarrhea with normal CT by GC24 and GC48, the diagnostic utility of CT change (∆GC) relative to sex-matched normal values. We evaluated two adult patient cohorts: 701 clinical patients (1994-2023) with chronic diarrhea and 76 research participants with irritable bowel syndrome with diarrhea (N = 63) or bile acid diarrhea (BAD, N = 13). Results of ∆GC were compared to 220 healthy controls' 95th percentiles (%ile) (≥2.0 females and ≥2.2 males). In the research cohort, we also analyzed (Spearman correlation) colonic ∆GC with ascending colon emptying T1/2 (AC T1/2), average stool frequency and consistency based on a daily diary, total fecal bile acid (BA) concentration, and % primary BA in a single stool sample. Among 701 clinical patients with normal GC24, 160 (22.3%) had rapid CT based on ∆GC 95th %ile in health. Among 76 research participants, an additional 20.6% IBS-D and 23% BAD had rapid CT ∆GC. Younger age and absence of diabetes mellitus were predictive of rapid ∆GC. ∆GC significantly correlated with AC T1/2 and with fecal BA. ∆GC identified an additional 21%-23% patients with rapid colonic transit among patients with diarrhea and normal GC24.

Supporting driver performance in closely spaced tunnel-interchange structure: Traffic control devices and effects on driving behavior

Objectives With the rapid development of expressways in the mountainous regions of southwestern China, closely spaced tunnel-interchange structures have inevitably emerged due to topographical constraints and environmental limitations. Given the unfavorable road geometry and rapid cross-section transitions, drivers face significant safety concerns. This study aims to investigate drivers’ safety performance at closely spaced tunnel-interchange sections and determine how safety risks can be mitigated through improved traffic control devices design. Methods Thirty-nine participants conducted an experimental study in a fixed-base simulator. The test scenario was modeled on the Xingyan Freeway-S3801 and accurately reproduced in the simulator. For each safety performance metric, the driving simulator experiments yielded a dataset with 780 observations. To address the idiosyncratic variation due to individual driver differences, a series of linear mixed effects models (LMM) were developed to analyze drivers’ behavior responses. Results In closely spaced tunnel-interchange sections, a general impairment of both longitudinal and lateral performance was observed. This study identified potential critical impact variables in traffic control device systems. According to the LMM results: (a) Removing the 0.5 km interchange ramp exit advance guide sign located in the tunnel exit area reduces dangerous behavior in the corresponding impact area. (b) Replacing the 0.5 km interchange ramp exit advance guide sign with arrow pavement markers as an information source supports improved driver performance, promoting driver safety. (c) Adding tunnel exit distance signs within tunnels is recommended to enhance situation awareness for drivers. Conclusions This study addresses the scientific issues related to traffic control devices setup for closely spaced tunnel-interchange sections, focusing on identifying potential critical impact variables. The findings provide guidance on the design of traffic control devices for such sections and support revisions to national engineering standards.

Urban heat transitions policy; Zooming in on Dutch natural gas-free neighbourhoods

Heating transitions, where residential and industrial heating demand transitions away from fossil fuels, are an essential part of sustainability transitions. Thus far, the focus on heating transitions is neglected in policy studies, even though policy interventions are not only understood as essential, but also difficult to implement. In this article we seek to understand how policy can support the heating transition in countries with high distribution of natural gas in household consumption. By aligning transition typologies, consisting of a discussion of transition paths and innovation frames, with policy intervention points to existing literature on policy studies of heating transitions, we identify lessons learned and factors necessary for rapid heating transitions. This allows us to understand which type of transition is best stimulated through which intervention point. We then applied this framework to the Dutch natural gas phase out package, to test and validate the framework, as well as identify policy gaps and failures for the Dutch context. Here we were able to highlight important policy gaps and identified potential failures for policy effectiveness. This framework may be used in future studies and by policymakers to understand policy gaps and potential failures, supporting the (re)design of policy packages.

Simplification of clean development mechanism to measure CO2 emission reductions from shifting private transportation to mass rapid transit: a case study of MRT Jakarta Phase 1

Background The Indonesian government built the Mass Rapid Transit (MRT) in Jakarta to reduce traffic congestion and carbon dioxide (CO2) emissions. The objective of this study is to estimate the CO2 emissions reductions from switching from private transport to MRT by using a methodology proposed by the United Nations Convention on Climate Change (UNFCCC) for developing countries, namely the Clean Development Mechanism (CDM) methodology, which generates Certified Emission Reductions (CERs). This methodology is more comprehensive than other available methodologies. However, this method has not been widely used to calculate greenhouse gas (GHG) emission reductions in mass transit projects because it is complex enough to require a lot of data based on primary surveys. Therefore, this research simplifies the CDM formula to make it easier and applicable in Indonesia. Methods The primary data were collected using a questionnaire distributed to 480 MRT Jakarta Phase 1 user respondents in September 2019 (baseline); the secondary data were obtained from The MRT Jakarta. The data were processed using IBM SPSS Statistics 27. The simplified Clean Development Mechanism Approved Consolidated Methodology 0016 (CDM ACM 0016) was the analysis method used. Result The results of this study indicate that 53.75% of MRT Jakarta Phase 1 users are shifting from private transportation, which has reduced CO2 emissions by 2,732.7 tons in 2019 and 6,043.9 tons in 2023. Increasing the number of MRT passengers who switch from private transportation will further reduce CO2 emissions. Conclusion and implications The simplified CDM ACM 0016 formula may be suitable for use in Indonesia. This would enable the measurement of CO2 emission reductions through mitigation actions through MRT development to be certified by the UNFCCC. Applying this method in calculating CO2 emission reductions, implementing strategies to increase MRT passengers, and using renewable energy electricity sources would increase CO2 emission reductions.

Visual Target Interaction Modeling with Multichannel Data Fusion

Facing the demand for accurate, fast, and natural human–computer interaction in the multi-screen control environment, the traditional exchange method of frequent switching control of multi-screen through mouse, keyboard, and other manual methods has problems of low efficiency, weak flexibility, and poor experience. In this paper, we research multi-screen precision control technology based on eye movement to break through the difficulties of precise recognition of human vision under complex environments and poor stability of vision estimation under frequent switching control of multi-screen. This study explores the technology for controlling multiple screens with high precision by tracking eye movements. It overcomes the challenges associated with reliably discerning human visual focus in intricate settings and the instability of visual assessments during rapid transitions between multiple screens. The experimental results of 1143 eye-movement capture tasks are studied, including the accurate recognition technology of human head posture and pupil gaze direction under complex backgrounds, illumination, and different visual field environments, and the theoretical modeling method of multi-screen precise target interaction based on eye-movement is explored. The expression data will be processed using convolutional neural networks, and the dataset will be trained through Python programming and tested on test samples collected by simulated flight crews in the laboratory with an accuracy rate of more than 85%.

From mangroves to womangroves to feminist foodscapes: (en)gendering research on indigenous food livelihoods in the Solomon Islands

AbstractPacific Island communities are facing rapid changes to their food systems in the context of globalization, environmental degradation and climate change. While in urban areas residents face a rapid nutrition transition, in rural environments, concerns are being raised about how to best maintain traditional food systems that are nutritious and sustainable. Mangrove forests are part of biodiverse food environments that support rural communities in the Pacific, but they are often overlooked in food system research because they occur between sea and land, and because gleaning mollusks and invertebrates from mangroves are considered mere subsistence practices carried out by women. In this paper, we draw from a feminist foodscape approach in feminist political ecology to discuss qualitative fieldwork from mangrove-adjacent communities in the Solomon Islands. We highlight the socio-ecological importance of mangrove foodscapes, along with the gendered and generational aspects of how environmental and food system change are experienced differently by community members in Marovo Lagoon. While conservationists are increasingly interested in the potential of mangroves for carbon sequestration, this research addresses the critical need to engage with mangroves’ social, cultural and gendered aspects– towards intertwined goals of gender equity, biodiversity and indigenous food sovereignty in the Pacific.

Impact of COVID-19 in the web accessibility of higher education institutions: a pending challenge

AbstractThe COVID-19 pandemic forced educational institutions to close and led to a radical transformation of the global education system. This process of change had to take place in a short period of time and, as a result, methodologies and learning tools were adapted. The closure of educational institutions and the disruption to learning impacted all students. However, vulnerable students, including those with disabilities, were particularly affected due to the lack of preparedness for inclusive learning during the rapid transition to emergency online learning. One of the many challenges faced by educational institutions during this transition was ensuring web accessibility for students with disabilities. However, it appears that some of the positive changes that took place in the education system during the pandemic, such as the enhancement of web accessibility, have been declining recently. The aim of this article is to review how a group of universities responded to the closure caused by the pandemic from the point of view of web accessibility, whether they improved the accessibility of their websites and whether this improvement has been maintained over time. To achieve this, the web accessibility of the home pages of selected universities around the world was evaluated against Web Content Accessibility Guidelines 2.1, for the period from 2018 to 2024. The results show that there was an improvement in web accessibility immediately after the COVID-19 outbreak, but this trend has not been maintained.

Reconstructing the rapid transitions of ecosystems during the mid-late Holocene: A pollen record from Haixing wetland in Bohai Bay, North China

Vegetation in coastal regions is sensitive to climate and sea-level changes. However, currently there is still a lack of understanding about the stability of the Holocene coastal ecosystem and the rapid conversion processes of different coastal wetland ecosystems. In this study, the high-resolution vegetation succession history of the southwest coast of Bohai Bay during the mid-late Holocene was revealed, based on pollen analysis and REVEALS model, and the rate of vegetation change was estimated. Furthermore, the characteristics and mechanisms of different ecosystem changes were explored. The results indicate that there was a prolonged transition from shallow sea to lagoon before the formation of the Haixing wetland during the interval of 7500–4100 cal yr BP. The rate of watershed vegetation change increase significantly under the common influence of the 4.2 ka event and human activities, causing a regime shift in the mountain forest ecosystems and a decrease in landscape resilience. It was characterized by a substantial reduction in broad-leaved forests (from>30% to<5%), especially for Quercus (∼3%), which have not recovered to pre-event levels since the end of the 4.2 ka event. Since 3500 cal yr BP, the Haixing area was completely detached from the influence of the Bohai Sea, forming freshwater wetlands. The local vegetation rapidly shifted from alkali-tolerant communities that followed the sea retreat to freshwater marsh plant communities. During 2000–1100 cal yr BP, under the strong impact of human activities, the succession of forest and grassland communities in the basin became more frequent. The area of coastal salt marshes expanded, with salt-tolerant plant communities taking the absolute advantage. The wetland vegetation landscape became closer to the modern appearance. Overall, our study provides new evidence for understanding the rapid evolution of coastal ecosystems in East Asia influenced by a combination of climate, hydrology and humans. It will help guide the coastal regions in facing the challenges of future global climate changes.

Assembly of Dye Molecules in Covalent Organic Frameworks for Enhanced Colorimetric Biosensing.

Colorimetric assays have been extensively investigated for biosensing applications due to their advantages of visual recognizability, ease of use, and low cost. However, advancing their development is a great challenge due to the inherent limitations of colorimetric dyes. Herein, we report a strategy to assemble dyes in covalent organic frameworks (COFs) to effectively reinforce the applicability of pH-responsive dyes in colorimetric bioassays. Experimental results reveal that three-dimensional COFs can promote the assembly of dyes through hydrogen bonding, resulting in the formation of a dye-supermolecule@COF assembly. Consequently, when sensitized at increased pH levels (e.g., hydroxyl ions), disruption of hydrogen bonds may trigger a rapid transition from their insoluble fixed state within the COFs into soluble, visibly detectable dye anions. This process can also be facilitated by increased hydrophilicity and elevated electrostatic repulsion between the dye anions and COFs, leading to the substantial release of chromogenic dye anions from the COF pores into the solution, thereby amplifying the colorimetric signal output. Therefore, by employing various synthesized dye-supermolecule@COFs as signal tags, we developed a colorimetric bioassay capable of accurately identifying breast cancer cell subtypes. This study not only highlights the effectiveness of dye-supermolecule@COFs in enhancing colorimetric biosensing but also underscores the potential of employing the COF-mediated dye assembly strategy for colorimetric assays.

Liquid crystal droplets formation and stabilization during phase transition process

Abstract The study of phase transition processes in liquid crystals (LCs) remains challenging. Most thermotropic LCs exhibit a narrow temperature range and a rapid phase transition from the isotropic (ISO) to the nematic (N) phase, which make it difficult to capture and manipulate the phase transition process. In this study, we observed the evolution of small droplets during the ISO-N phase transition in ferroelectric nematic (NF) LC RM734. After doping with metal nanoparticles (NPs), the temperature range of the phase transition broadened, and the droplets formed during the phase transition remained stable, with their diameter increasing linearly with temperature. In addition, droplets doped with NPs can be well controlled by an external electric field. This discovery not only aids in understanding the fundamental mechanisms of LC phase transitions but also provides a simple alternative method for preparing droplets, which is potentially valuable for applications in optoelectronic devices and sensors.

Online Learning Resources for Radiology Education: An Educational Perspective

The COVID-19 pandemic significantly disrupted radiology education, leading to a rapid transition from traditional in-person instruction to online learning. This article reviews the innovative digital tools and strategies adopted during this period, such as microlearning, virtual reality, and tablet apps, which were central in maintaining educational quality. While online platforms offered flexibility, accessibility, and global reach, challenges such as the lack of personal interaction and variability in resource quality persisted. The article emphasizes the importance of balancing online and in-person learning and highlights future directions in radiology education, including the integration of Artificial Intelligence (AI) and Virtual Reality (VR) to enhance training. By leveraging these advancements, radiology education can continue to evolve, offering comprehensive and adaptable learning experiences for trainees.

Discovery Process Chemistry: An Innovation Hub at the Interface of Academia, the Pharmaceutical Industry, and Contract Research Organizations

AbstractDiscovery Process Chemistry (DPC) is an emerging intersectoral space that is characterized by the development of new chemical reactions or syntheses that enable the efficient elucidation of structure-activity relationships (SARs) and structure-property relationships (SPRs) as well as a rapid transition to process development. Drug discovery and development are accelerated by such efforts and this has led chemists in academia and industry alike to place an increasing importance on these aims. In this Short Review, we explore recent advances in DPC and the impact that it can have on SAR/SPR interrogation and downstream drug development efforts.1 Introduction2 Enabling SAR/SPR Interrogation with Bioisosteres3 Couplings of Diversifiable Reaction Partners4 Late-Stage Functionalization5 Conclusion and Outlook

Limited input and the acquisition of Finnish: The evolution of a child speaker in a multilingual environment

Aims and Objectives/Research Question: This is a case study of a toddler acquiring Finnish in a trilingual (Finnish–Spanish–English) setting. Despite the apparent ease of the child’s acquisition of Finnish, the pressure of the majority language (English) suppresses the use of the acquired minority language. Is it feasible to expect an early-childhood minority language to be maintained at the level of production? Design/Methodology: Video-recordings were collected in domestic settings, mostly with the Finnish-speaking mother in interactions with the child, who was between the ages of 3;6 and 4;6. The approach follows loosely the principles of interactional sociolinguistics. Data and Analysis: The data were collected in 2008, when the child was 3 years old, and the follow-up data 8 months later, when the child was four. Samples of this corpus are analyzed in detail for the emerging target-like Finnish case endings and verbal inflections, as well as for deviations from adult Finland Finnish. The mother’s strategies of maximizing the effects of the limited input are also discussed. Findings/Conclusions: Even though the input the child receives is limited, his acquisition of Finnish morphosyntax follows monolingual patterns and shows overgeneralizations typical of monolingual Finnish children’s language. Some transfer from the contact with English and Spanish languages is present. The question of ultimate attainment in a heritage-language situation is addressed. Originality: The study is rare, as it documents the rapid transition from the child’s well acquired minority language to English, the majority language, in the matter of months. Significance: This article confirms the vulnerability of childhood bilingualism: even a few months between the two longitudinal datasets show a sharp decline in the child’s output in the heritage Finnish, but the dichotomy between “maintenance” versus “loss” is challenged because the decline in output does not necessarily extend to the loss of comprehension.

“I feel like it's just really become second nature, almost like the screen’s not there”: a qualitative case study of the transition to telehealth for home visitation program to support fragile infants due to the COVID-19 pandemic

A subset of early childhood home visitation programs support fragile infants and prevent hospital readmission as infants transition out of the neonatal intensive care unit (NICU) into their home. However, the COVID-19 pandemic initiated an unexpected change in the delivery of home visitation care to adhere to social distancing guidelines, resulting in a rapid transition into telehealth services. In this study, individual semi-structured interviews were conducted with staff from a NICU-transition home visitation program in Arizona. The Modified Technology Acceptance Model (MTAM) was used to evaluate the experiences of in-person to telehealth home visitations during the COVID-19 pandemic. Rapid Qualitative Analysis Method was utilized to generate a thematic analysis. Three major themes were identified: staff-centric, family-centric, and the experience of collective adjustment to the stressors of the pandemic. Participants faced challenges transitioning to telehealth visits, including not being able to physically demonstrate development skills on the infant. However, the telehealth model allowed staff to serve a larger geographic area, as well as allowing them to build a larger caseload as they had more control over their schedule. Staff also noted that families appreciated telehealth home visits as an added layer of health protection for their fragile infants. Because the transition to telehealth was abruptly necessitated by the COVID-19 pandemic, the study participants did not have the option to not use telehealth; thus, in the future, the MTAM framework could benefit from adaptions that address the rapid adoption of technology due to large disruptors such as COVID-19.

Perioperative anesthetic management of patients with hypoplastic left heart syndrome undergoing the comprehensive stage II surgery-A review of 148 cases.

Patients with hypoplastic left heart syndrome undergo the comprehensive stage 2 procedure as the second stage in the hybrid approach toward Fontan circulation. The complexity of comprehensive stage 2 procedure is considered a potential limitation, and limited information is available on its anesthetic management. This study aims to address this gap. A single-center retrospective cohort study analyzed 148 HLHS patients who underwent comprehensive stage 2 procedure, divided into Group A (stable condition, n = 116) and Group B (requiring preoperative intravenous inotropic therapy, n = 32). Demographic data, intraoperative hemodynamics, anesthetic management, and postoperative outcomes were collected. Etomidate (40%) was the most common induction agent, followed by esketamine (24%), midazolam (16%), and propofol (13%). Inhaled induction was rarely necessary (2%), occurring only in Group A patients. No statistical differences were found between groups for induction drug choice. Post-cardiopulmonary bypass management included moderate hypoventilation, inhaled nitric oxide (100%), and hemodynamic support with milrinone (97%) and norepinephrine (77%). Group B patients more frequently required additional levosimendan (20%) and epinephrine (18%). Extracorporeal membrane oxygenation was necessary in 8 patients (5%) with no between-group differences. Switching from fentanyl to remifentanil reduced postoperative ventilation time overall. However, Group B experienced significantly longer ventilation (6.3 vs. 3.5 h) and ICU stay (22 vs. 14 days). In-hospital mortality was 5% overall (Group A: 4%, Group B: 9%). Long-term survival analysis revealed a significant advantage for Group A. The use of short-acting opioids and adjusted ventilation modes enables optimal pulmonary blood flow and rapid transition to spontaneous breathing. Differentiated hemodynamic support with milrinone, norepinephrine, supplemented by levosimendan and epinephrine in high-risk patients, can mitigate the effects on the preoperatively volume-loaded right ventricle. However, differences in long-term survival probability were observed between groups. Local ethics committee, Medical Faculty, Justus-Liebig-University-Giessen (Trial Code Number: 216/14).

Rapid Transition to Online Learning: Faculty Distance Training on LMS, Synchronous/Asynchronous Learning, and Computer-Assisted Assessment

This study examines the swift shift to online learning prompted by the Covid-19 pandemic, assessing the effectiveness of a faculty distance training program based on the TMOC (Training for the Management of Online Courses) model. The training program aimed to equip faculty with essential skills for online learning, emphasizing a blend of asynchronous learning materials and synchronous support. Key components included training in the Learning Management System (LMS), video capture tools, synchronous learning platforms, and Computer-Assisted Assessment (CAA). The research surveyed a sample of faculty members (n=38), assessing their views towards the training they received. The findings highlight that faculty greatly valued personalized, real-time assistance, which proved instrumental in tackling immediate technical and pedagogical hurdles. High-quality asynchronous resources were also pivotal, offering flexibility and foundational knowledge. The training resulted in noticeable enhancements in faculty engagement and proficiency in online learning, particularly among those less familiar with digital educational methods. Qualitative feedback emphasized the significance of timely, customized support and collaborative assistance. The study underscores the imperative of holistic training programs that blend technical and pedagogical aspects to facilitate a seamless transition to online learning. These insights offer valuable guidance for institutions seeking to bolster their online education capabilities during emergency situations.

Insights of mechanism and kinetics of acrylonitrile aqueous precipitation polymerization

Aqueous precipitation polymerization is commonly used in the industry due to its efficient heat dissipation, reaction stability and production flexibility. However, its mechanisms and kinetics are still partially unclear. The ammonium persulfate-ammonium sulfite monohydrate (APS-AS) initiated aqueous phase precipitation polymerization of acrylonitrile (AN) at low concentration was deeply investigated, with the APS initiation system as a control. The apparent kinetic equations for the APS and APS-AS initiation systems were determined to be Rp= K[AN]1.706[(NH4)2S2O8]0.704 and Rp= K[AN]3[(NH4)2S2O8]0.704[(NH4)2S2O3]−1.055, respectively. Monitoring AN distribution in the aqueous and polyacrylonitrile (PAN) phases revealed a rapid transition of the reaction site from the aqueous phase to the PAN phase following polymer precipitation. Zeta potential and primary particle number exposed that the nucleation site disparities between initiation systems led to different predominant factors affecting the polymerization rate. The change in molecular weight during polymerization had a maximum due to its dependence on the monomer concentration. The crystallinity of the product initially increased during polymerization, then decreased and eventually stabilized. Scanning electron microscopy (SEM) revealed that the diameter of the internal particles was larger, while the surface particles were smaller after coagulation. These findings offer crucial insights for optimizing aqueous precipitation polymerization and PAN particle property control.

Ultrahigh Néel Temperature Antiferromagnetism and Ultrafast Laser-Controlled Demagnetization in a Dirac Nodal Line MoB3 Monolayer.

Two-dimensional (2D) antiferromagnetic (AFM) materials boasting a high Néel temperature (TN), high carrier mobility, and fast spin response under an external field are in great demand for efficient spintronics. Herein, we theoretically present the MoB3 monolayer as an ideal 2D platform for AFM spintronics. The AFM MoB3 monolayer features a symmetry-protected, 4-fold degenerate Dirac nodal line (DNL) at the Fermi level. It demonstrates a high magnetic anisotropy energy of 865 μeV/Mo and an ultrahigh TN of 1050 K, one of the highest recorded for 2D AFMs. Importantly, we reveal the ultrafast demagnetization of AFM MoB3 under laser irradiation, which induces a rapid transition from a DNL semimetallic state to a metallic state on the time scale of hundreds of femtoseconds. This work presents an effective method for designing advanced spintronics using 2D high-temperature DNL semimetals and opens up a new idea for ultrafast modulation of magnetization in topological semimetals.

Impact of the Peripheral Ligand Layer on the Excited-State Deactivation Mechanism of Au38S2(S-Adm)20 and Au30(S-Adm)18 (S-Adm = Adamantanethiolate) Clusters.

Gold nanoclusters are ideal fluorescent labels for biological imaging, disease diagnosis, and treatment. Understanding the origin of the photoluminescence phenomenon in ligand-protected gold nanoclusters is crucial for both basic science and practical applications. In this study, density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations were performed to study the mechanism of excited state deactivation of Au38S2(S-Adm)20 and Au30(S-Adm)18 (S-Adm = adamantanethiolate) clusters, which have similar sizes and compositions. The computational results indicate that the differences in structural symmetry and peripheral ligand layer lead to quite different excited state deactivation mechanisms and excited state lifetimes in Au38S2(S-Adm)20 and Au30(S-Adm)18. Specifically, the μ3-S atoms and bridging thiolate (SR) in the ligand layer of Au38S2(S-Adm)20 significantly suppress the structural relaxation of ligand motifs, resulting in a prolonged excited state lifetime and higher quantum yield. For the Au30(S-Adm)18, due to the symmetry forbidden and large structural relaxation of the ligand shell, a rapid nonradiative transition process resulted. This study provides new insights into how the photoluminescence of ligand-protected gold nanoclusters is influenced by their structure and symmetry.

Colonic long-term retention and colonization of probiotics by double-layer chitosan/tannic acid coating and microsphere embedding for treatment of ulcerative colitis and radiation enteritis

Oral probiotics can alleviate enteric inflammations but their rapid transit through the gut limits their retention and colonization in the colon. Here, a novel strategy integrating the bacterial double-layer coating and hydrogel microsphere embedding techniques was used to highly enhance the colonic retention and colonization efficiency of Lactobacillus rhamnosus GG (LGG). LGG was coated by the double layers of chitosan (CS) and tannic acid (TA), and then embedded in calcium alginate (CA) hydrogel microspheres to form LGG@CT@CA. The microspheres resisted gastric liquids, improving LGG safe transit through the stomach to reach the colon. LGG@CT was rapidly released in the colon due to the good swelling of hydrogel microspheres. More importantly, LGG exhibited long-term retention up to 7 days in the colon and colonized the deep site of the colonic mucosa. LGG@CT@CA had a high therapeutic efficiency of ulcer colitis with the long colon and the low intestinal permeability of colonic tissues. LGG@CT@CA also alleviated the small intestinal damage induced by irradiation and the survival rates were improved. The mechanisms included local ROS decrease, IL-10 increase, and ferroptosis reduction in the small intestine. The oral colon-targeted system holds promise for oral probiotic therapy by the long-term retention and colonization in the colon.