Limited Contact Research Articles

Use of biosecurity practices to prevent chronic wasting disease in Minnesota cervid herds

The objective of this study was to evaluate biosecurity practices related to chronic wasting disease (CWD) transmission pathways and prevention in active cervid herds in Minnesota in 2019 by species, size and location of herds. A self-administered questionnaire was sent to all cervid producers in Minnesota to gather demographic, management, and biosecurity practices. Among producers (N=136), 63.2 % raised predominantly deer species and 36.8 % raised predominantly elk or reindeer. Survey responses were analyzed by herd species (deer or elk/reindeer), herd size (<20 or ≥20 animals), and location (southeast Minnesota or rest of the state) to determine statistical differences between strata. In terms of CWD transmission risks from other farmed cervids, 40.4 % (95 % Confidence Intervals (CI) 32.1–48.8) of Minnesota producers stated they introduced new cervids to the operation in the previous 3 years, though there were minimal other forms of direct contact. A higher percentage of larger sized elk/reindeer herds reported practices that indicate potential for indirect contact with other farmed cervids. Vehicles or trailers that entered the farm were used to transport other live cervids, cervid carcasses, or cervid body parts in past 3 years in 64.3 % (95 % CI 46.3–82.3) of larger elk/reindeer herds compared to 13.6 % (95 % CI 4.7–22.4) of smaller deer herds.For CWD transmission risks from wild cervids, limited potential direct contact was reported. Among all producers, 9.6 % (95 % CI 4.6–14.6) reported farmed cervid escapes in the past 3 years (even temporarily) and 0.7 % (95 % CI 0.0–2.2) of producers reported wild white-tailed deer (WTD) inside perimeter fencing. Additionally, 24.3 % (95 % CI 17.0–31.6) of producers observed wild WTD near the perimeter fencing in the past 12 months and 18.7 % (95 % CI 12.0–25.3) reported use of double perimeter fencing, indicating frequent proximity to wild deer and potential for direct and/or indirect contact exposures. Further, 14.3 % (95 % CI 6.7–21.9) of deer herds and 30.0 % (95 % CI 17.1–42.9) of elk herds reported potential access of wild cervids to hay/silage while stored on the farm, with similar results comparing smaller and larger size strata (13.8 % (95 % CI 6.1–21.4) and 29.6 % (95 % CI 17.3–42.0), respectively). Contact through hunting or taxidermy practices occurred infrequently, with the exception of 20.1 % (95 % CI 13.3–27.0) of producers reporting bringing outside hunted cervid parts/carcasses onto property in the past 3 years.Overall, results identified direct and indirect contact exposures from both farmed and wild cervids to Minnesota herds, with many producers reporting potential contact with wild cervids through direct and multiple indirect pathways. Many of these indirect exposures to wild and farmed cervids varied by herd size and species strata. Better understanding of these potential CWD transmission pathways and how differences between herd size and species affect these pathways will facilitate development of more effective biosecurity programs for cervid herds.

Development of a New Correlation Model for Heat Transfer in Solar Air Heater with Corrugated Absorber Plates Using Swarm Optimization

Solar air heaters play a crucial role in distributing heated air at low to medium temperatures. The heart of these systems lies in the absorber plate, which directly absorbs solar heat energy and then efficiently transfers it to the flowing air. However, the challenge lies in achieving optimal thermal efficiency by modifying the absorber plate roughness. Traditional smooth absorber plates have a limited contact area for heat transfer, leading to suboptimal performance. Using passive techniques, such as corrugation on the absorber plate, may increase thermal efficiency by creating turbulence in the laminar sublayer. In this study, corrugated solar air heaters are considered, with the absorber plates roughened into square, semicircular, and triangular ribs. The flow characteristics of heat due to the roughness of the absorber plate is simulated using the computational fluid dynamic (CFD) technique. The ANSYS Fluent 2019R3 is used to investigate the turbulent air flow in the absorber plate. The simulation analyses are performed over a Reynolds number range of 4000–18,000 using three different pitches. As the main contribution, two different model equations, namely M1 and M2, for the correlation model of the solar heat transfer were proposed to predict the Nusselt number, where M2 is an original model and M1 is newly established with the fine-tuned coefficients. Also, for the first time in the literature, the recent swarm optimization algorithm, namely Honey Formation Optimization with Single Component (HFO-1), is used to optimize the solar air heater and a comparison study with a popular non-swarm optimization, namely the Generalized Reduced Gradient (GRG) optimization, is provided. The Nusselt number was obtained using HFO-1 with a percentage error (MAPE) of 2.15% and 0.86% for the models M1 and M2, respectively. Moreover, the average achievement of HFO-1 on the proposed correlation models is 50% better than that of the GRG optimization, with respect to the RMSE.

Assessment of Practice Preparedness among Novice Nurses in Private Hospitals: A Cross-sectional Study

Background. The crop of novice nurses who are currently employed is a product of flexible learning who had limited contact hours with actual patients, which is contrary to those who graduated from traditional learning modalities. Hence, it is essential to evaluate how the impact of flexible learning modality has affected the practice preparedness levels of novice nurses in the hospital setting. Objective. This study aimed to determine the level of practice preparedness and its associated factors among novice nurses who work in private hospitals. Methods. The study utilized a cross-sectional survey design. Data was gathered from a total enumeration of ninetyfour novice staff nurses who graduated from the flexible learning curriculum and are currently employed in private hospitals in Baguio City and La Trinidad. The tool used was a questionnaire in two parts. Part 1 consisted of questions related to demographic information and factors related to practice preparedness, and part 2 included the Nursing Practice Readiness Scale, with validity and reliability scores of &gt;0.924 and 0.90, respectively. The data was analyzed using the SPSS V27 trial version. The protocol was approved by the Saint Louis University Research Ethics Committee. Results. Findings reveal that more novice nurses in private hospitals perceived themselves as well-prepared across all domains of practice preparedness: “Collaborative Interpersonal Relationship” (n = 94, 100%); “Patient Centeredness” (n = 92, 97.90%); “Self-regulation” (n = 90, 95.70%); “Clinical Judgment and Nursing Performance” (n = 78, 83.00%); and “Professional Attitudes” (n = 76, 80.90%). There is a significant association between practice preparedness and the following factors: “Attended more than one Training/Seminars per year” (p = 0.02), “Graduated from Private Schools” (p = 0.03), and “Assigned in Regular Wards” (p = 0.05).On the other hand, no significant association was found between practice preparedness and the following factors: “Sex” (p = 0.61) and “Membership in Professional Organizations” (p = 0.73). Conclusion. In agreement with existing studies, practice preparedness is multifactorial. However, what this study contributes are new factors that are favorable in making novice nurses more confident in performing their roles and responsibilities. These include being a graduate of private schools, being assigned to regular wards, and attending professional training/seminars more than once annually. Advantageously, these factors that promote practice preparedness are modifiable.

Obstacles in Instructing English at Village Elementary Schools in Bangladesh: A Study and Proposals

Elementary education serves as the foundation for students' future endeavors. Each year, many students in rural Bangladesh fail public examinations, and those who pass often do so by rote memorization, lacking proficiency in the four key language skills required for competence in English. Primary education was chosen for this study as it is a crucial stage where teachers bear full responsibility for student learning. The primary objective of this research was to identify the obstacles in teaching and learning English at the elementary level in rural areas of Bangladesh. Data were gathered using two sets of questionnaires administered to both students and teachers to assess the state of English language education in these primary schools. Additionally, teacher interviews and classroom observations, guided by an observation checklist, were conducted to gain a comprehensive understanding of the current teaching practices. The findings reveal that the majority of rural students struggle with English due to several factors, including a shortage of skilled and trained teachers, inadequate teacher training, inappropriate teaching methods and materials, limited contact hours, large class sizes, and insufficient pedagogical knowledge. This paper also includes several recommendations based on the research findings to address these challenges effectively.

Social isolation induces addictive behavior and increases release of dopamine in the &lt;i&gt;nucleus accumbens&lt;/i&gt; in response to stimulation of the positive reinforcing zone

The study of the role of social isolation in the pathogenesis of addictive behavior disorders is an important medical and biological problem. Of particular importance are the limitations of social experience in ontogenesis. This work makes an attempt to find a connection between social isolation in ontogenesis and impulsive-compulsive behavior, as an indicator of the premorbid background for gaming and other forms of behavioral addictions. The mechanisms of addictive behavior in rats reared in isolation (IS) were investigated by analyzing the extracellular release of dopamine in response to stimulation of the positive reinforcing zone. Before the experiments, male rats were kept in individual cages from the 21st day of birth to the 90th day. To study elements of addictive behavior, a variant of the Iowa Gambling Task in a 3-arm maze and a method of developing compulsive overeating using intermittent consumption of high-calorie foods were used. To study compulsive behavior, a marble test was used against the background of withdrawal from a high-calorie diet. Surgeries were performed to implant electrodes into the ventral tegmental area (VTA) and the nucleus accumbens in rats exhibiting elements of addictive behavior in the 3-arm maze. These animals were then trained to respond to VTA self-stimulation. Dopamine release was recorded telemetrically in freely moving rats in response to electrical stimulation of the VTA self-stimulation zone. Fast scan cyclic voltammetry was used to determine changes in dopamine levels in the extracellular environment of the nucleus accumbens. IS entered less into the arm with a high degree of probability but with a low reward, and entered more in the arm with a low degree of probability, but with a high reward, which is associated with the appearance of impulsivity in behavior. In the model of compulsive overeating, the number of approaches to the feeder in IS increased, and against the background of withdrawal of high-calorie food, IS were more active in the marble test. In IS exhibiting elements of addictive behavior in the 3-arm maze, the content of extracellular dopamine in response to electrical stimulation of the VTA self-stimulation zones did not reveal any differences compared to the control group of rats with addictive behavior in the maze. At the same time, IS exhibiting elements of addictive behavior in the maze showed a more pronounced dopamine response to a complex stimulus: a conditioned signal used during maze learning light + VTA stimulation. Thus, rearing in the IS causes an increase in dopamine release in the nucleus accumbens in response to stimulation of the positive reinforcement area associated with addictive behaviors: impulsivity and compulsivity. A conclusion is drawn about the prospects of studying the extracellular release of dopamine and assesses addictive behavior disorders caused by limited social contacts in ontogenesis.

An advanced closed-loop geothermal system to substantially enhance heat production

Heat production through conventional closed-loop geothermal systems is constrained by the limited contact area for heat exchange between rock formations and the wellbore. To address this challenge, an advanced closed-loop geothermal system (ACGS) is proposed to enhance heat production in this research. The ACGS incorporates a hydraulic fracture, partitioned by a horizontal insulator for vertical zonal isolation of fluid flow in the fracture, into the closed-loop system’s fluid circulation. To assess heat production from the ACGS, a three-dimensional ACGS numerical model is established and validated, utilized to simulate heat production through the ACGS under conditions of different fracture dimensions and structures, tubing materials, and fluid heat capacities. Performances of complicated fracture structures, including a branched fracture and a multiple-wing fracture, in improving heat production are evaluated. It is found that due to the incorporation of a double-wing fracture, the cumulative extracted heat of a closed-loop system over 20 years is enhanced by 162.94 %. Increasing fracture half-length and fracture height both enhances the heat production of the ACGS considerably. Polyurethane foam proves an excellent tubing material for the ACGS due to its low cost and outstanding adiabatic functionality. Compared with a multiple-wing fracture, a branched fracture results in better heat production through the ACGS, with more fracture branches leading to higher heat production. A branched fracture can improve the cumulative extracted heat from a closed-loop system over 20 years by 321.77 %, and increasing the inter-branch angle further enhances heat production. Working fluid with smaller heat capacity yields considerably higher outlet temperature.

Barriers and facilitators to culturally sensitive care in general practice: a reflexive thematic analysis

BackgroundThis study investigated the perceived barriers and potential facilitators for culturally sensitive care among general practitioners in Flanders. Understanding these dynamics is crucial for improving healthcare quality and equity.MethodologyTwenty-one in-depth interviews were conducted with Flemish GPs. Braun and Clarke’s reflexive thematic analysis was employed to develop and interpret themes that elucidate shared underlying meanings and capture the nuanced challenges and strategies related to cultural sensitivity in healthcare.ResultsTwo core themes were generated: GPs’ uncertainty and opposition. These themes manifest in emotional responses such as frustration, miscomprehension, and feelings of helplessness, influencing relational outcomes marked by patient disconnect and reduced motivation for cultural sensitivity. The barriers identified are exacerbated by resource scarcity and limited intercultural contact. Conversely, facilitators include structural elements like interpreters and individual strategies such as engagement, aimed at enhancing GPs’ confidence in culturally diverse encounters. A meta-theme of perceived lack of control underscores the challenges, particularly regarding language barriers and resource constraints, highlighting the critical role of GPs’ empowerment through enhanced intercultural communication skills.ConclusionAddressing GPs’ uncertainties and oppositions can mitigate related issues, thereby promoting comprehensive culturally sensitive care. Essential strategies include continuous education and policy reforms to dismantle structural barriers. Moreover, incentivizing culturally sensitive care through quality care financial incentives could bolster GP motivation. These insights are pivotal for stakeholders—practitioners, policymakers, and educators—committed to advancing culturally sensitive healthcare practices and, ultimately, for fostering more equitable care provision.

Quiet Pandemic Amid COVID-19: A literature review on gamification for mental health

Background: COVID-19 affects individuals both physically and mentally. The key is to address emerging needs with a modest technique that helps boost the positive approach in individuals. Gamification offers attempts to engage users with the non-game approach, and its growing popularity in other fields, such as finance and retail, is evident. Objective: This research aims to study the available literature that analyzes and understands using the Gamification approach for mental health in the pandemic. Methods: The author performed a systematic literature review using the PRISMA technique among the selected articles published until Jul 2023, focusing on Gamification, mental health, and COVID in highly reputed record databases, which were peer-reviewed studies. Therefore, the studies using the standard international language of English were eligible for this Study. Results: The Study identified elevated articles exploring Gamification through mobile application software, web-based platforms, and other tools since COVID-19 limited in-person social contact for individual safety during peak time. Conclusion: There are limited studies of Gamification in mental health, and the existing studies suggest that Gamification supports the betterment of mental health. Future studies can explore the different areas of mental health with gamification-based applications or gamified approaches.

Travel Intentions Towards Contact Limited Tourism: A Survey of Students and Lecturers in Vietnam

ABSTRACT The study on contact limited tourism stems from consumer behavior research dedicated to reducing customer interaction in consumer services. Its primary focus was to examine the behavioral intentions of tourists amid the post-COVID-19 pandemic, specifically exploring the concept of contact limited tourism. The investigation involved surveying students and lecturers in the Ho Chi Minh City area, employing the Theory of Planned Behavior model. This model helped assess how individuals’ perceptions of COVID-19 risks influenced their inclination to partake in travel with limited contact. The research findings highlight that factors like risk perception, subjective norms, and behavior control positively impact travel attitudes favoring limited contact. These results hold significance as specifically explore the concept of contact limited tourism, shedding light on the importance of reduced physical interactions in travel. This insight is valuable for designing and marketing tourism services in a post-pandemic era.

NEGLECTED BOTH-BONE FOREARM FRACTURE WITH DISTAL RADIOULNAR JOINT DISLOCATION: A CASE REPORT AND BRIEF LITERATURE REVIEW

Introduction: In this case, we discuss a patient with a neglected and malunited both-bone forearm fracture with distal radioulnar joint dislocation. This pattern of fracture by itself is uncommon, but the initial negligence of this trauma makes it even more rare and challenging for surgical treatment. Case report: The main aim of the surgery was to restore the forearm's function and anatomy. After thorough preoperative preparation, including planning the level of resections, the patient was treated with open reduction and internal fixation with a limited contact dynamic compression plate. The distal radio-ulnar joint was fixed with 2 K-wires. On control follow-up six months later, the resection sites were fully consolidated, with no visible deformation of the forearm. Pronosupination was restored up to 60% of normal functional arc. Conclusion: This case has shown that even with careful restoration of forearm anatomy, results of the surgical treatment in neglected and malunited both-bone forearm fracture with distal radioulnar dislocation will not be a priori good or excellent. Surgeons need to remind the patients that the return of the function of the upper limb to the degree before the trauma cannot be guaranteed.

Motivation and Engagement of Students: A Case Study of Automatics and Robotics Projects

Automatics and Robotics students usually engage in some interdisciplinary approaches on their courses at universities, joining the areas of computer science and control theory. During the limited duration of these courses, some knowledge must be acquired by the students. Remote education, temporarily enforced by the COVID-19 pandemic in recent years, has posed new challenges related to the limited contact that students have with academic staff, as well as the limited access students have to hardware facilities. This paper discusses the motivations of students after the COVID-19 pandemic based on a case study of student projects completed at the University of Zielona Gora (Poland). The conducted study was student-centered and highlighted some important aspects of motivation from the point of view of the students, focusing mostly on the emerging challenges, how they have been overcome, and what the students have learned from them. The results indicate that the students, minimally supported by an academic teacher, were able to plan everything by themselves and bring the project to completion according to their own intuition. In comparison to before the COVID-19 pandemic, students are now more independent and self-motivated.

A comparative study of microstructure and mechanical properties for carbon fibers and carbon nanotubes reinforced copper composites doped by Zr70Cu30 particles

Carbon fibers (CFs) and carbon nanotubes (CNTs) reinforced Cu composites doped by Zr70Cu30 alloy particles were fabricated by a conventional vacuum hot-press technique and their microstructures, mechanical properties and electrical conductivities were compared. The results revealed that the CNTs/Cu composite exhibited a superior combination between mechanical properties and electrical conductivity, having the highest relative density of 94.8 %, the maximum microhardness of 85.7 HV and the maximum electrical conductivity of 84.2 % IACS among various composites. The incorporation of Zr70Cu30 alloy particles led to limited contacts with CFs (or CNTs) reinforcements but caused the decrease of relative density and consequently the deleterious mechanical and electrical properties. The dominant strengthening mechanism for the fabricated Cu matrix composites was load transfer mechanism. The CNTs reinforcements demonstrated the highest reinforcement efficiency in the Cu matrix composites, which can provide some new insights for designing novel high-strength and high-connectivity Cu matrix composites.

Validation of a Commercial ELISA Kit for Non-Invasive Measurement of Biologically Relevant Changes in Equine Cortisol Concentrations

The measurement of fecal cortisol/corticosterone metabolites (FCMs) is often used to quantify the stress response. The sampling method is relatively non-invasive, reduces concern for elevation of cortisol from the sampling method, and has been shown to measure cortisol more consistently without the daily diurnal rhythm observed in blood. Commercial ELISA (enzyme-linked immunoassay) kits offer benefits over previously validated immunoassay methods but lack validation. The objective of this study was to evaluate a commercial ELISA kit (Arbor AssaysTM DetectX® Cortisol ELISA kit, K003-H1, Ann Arbor, MI, USA) and provide analytical and biologic validation of equine fecal and plasma samples. Horses (4 male, 4 female, mean ± SD: 4 ± 5 yr) were transported for 15 min with limited physical and visual contact via a livestock trailer. Blood and fecal samples were collected pre- and post-transportation. Parallelism, accuracy, and precision tests were used to analytically validate this kit. Data were analyzed using PROC MIXED in SAS 9.4. Plasma cortisol concentrations increased in response to trailering (254.5 ± 26.4 nmol/L, 0 min post-transportation) compared to pre-transportation (142.8 ± 26.4 nmol/L). FCM concentrations increased 24 h post-trailering (10.8 ± 1.7 ng/g) when compared to pre-transportation (7.4 ± 1.7 ng/g). These data support that changes in FCMs can be observed 24 h post-stressor. In conclusion, the Arbor AssaysTM DetectX® Cortisol ELISA kit is a reliable, economic option for the measurement of biologically relevant changes in cortisol in equine plasma and FCMs.

Postnominal flagging and OV in Sinitic

Abstract Sinitic languages are known for their SVO order and mostly isolating morphology. This study addresses eleven languages of four different areas in Hunan, Yunnan, Sichuan, and Qinghai/Gansu provinces in China that possess SOV order and developed a postnominal flagging system. This study presents a synchronic description as well as a diachronic analysis of the flagging systems in these languages, focusing on typological properties (ergative or secundative alignment) and the role of language contact. The existence of four separate areas with limited mutual contact allows a contrastive approach and inferences on the role of different contact languages (Tibetic, Mongolic, Tujia) or different types of language contact (borrowing of flags, shared grammaticalization). The study argues against OV order and postnominal flagging as defining features of the “Amdo Sprachbund”, showing that these are universally present in all four areas and are better understood as the result of contact between two Eurasian macro areas.

A Multi-Electrode Array Platform for Modeling Epilepsy Using Human Pluripotent Stem Cell-Derived Brain Assembloids.

Human brain organoids are three-dimensional (3D) structures derived from human pluripotent stem cells (hPSCs) that recapitulateaspects of fetal brain development. The fusion of dorsal with ventral regionally specified brain organoids in vitro generates assembloids, which have functionally integrated microcircuits with excitatory and inhibitory neurons. Due to their structural complexity and diverse population of neurons, assembloids have become a useful in vitro tool for studying aberrant network activity. Multi-electrode array (MEA) recordings serve as a method for capturing electrical field potentials, spikes, and longitudinal network dynamics from a population of neurons without compromising cell membrane integrity. However, adhering assembloids onto the electrodes for long-term recordings can be challenging due to their large size and limited contact surface area with the electrodes. Here, we demonstrate a method to plate assembloids onto MEA plates for recording electrophysiological activity over a 2-month span. Although the current protocol utilizes human cortical organoids, it can be broadly adapted to organoids differentiated to model other brain regions. This protocol establishes a robust, longitudinal, electrophysiological assay for studying the development of a neuronal network, and this platform has the potential to be used in drug screening for therapeutic development in epilepsy.

Experience of final exam stress from Polish high school students. The narrative of COVID-19 Pandemic Generation

Introduction: For many students worldwide, school achievements and final exams results are a significant challenge and are understood as determinates of their future college and university education, as well as their professional career. The COVID-19 pandemic not only forced schools to close and a ban on gatherings, but also introduced many new solutions and measures regarding the conduct of final exams, for which students had been preparing for years. In Poland, the government shut schools in 2020, two months before the usual time for final exams. This significant factor required modification in the manner and course of the final stage of preparation for the ‘maturity’ exam, which resulted in limited contact with teachers and peers, leading to intense emotions and personal challenges. Method: The study aim was to point out the specific COVID-19 stress experience of high school students who were on the verge of graduating. 120 high school students from South Poland [40 men (33%) and 80 women (66%), aged 18-19 years], who were preparing for the final high school exam in Poland in 2020, participated in the online survey. Phenomenological content analysis of the structured open-ended questionnaire was used. Results: It was found that the subjective experiences of students were mostly negative to Covid-19 restrictions and remote learning, expressed not only as negative emotions to the new, surprising, and hence fearful situation, but also as negative attitude s towards routine changes. The strong need to develop new adaptation mechanisms necessary to cope with the isolating circumstances was also explored. Conclussions: The study provides new supplements on mental health prevention (not only during pandemic) in students who were on the verge of graduating.

The effect of social factors on eye movements made when judging the aesthetic merit of figurative paintings

In the present study we explore how social factors (group contact, individuating experience, implicit racial bias) influence the eye movements made during the visual exploration when judging their aesthetic merit of figurative paintings depicting White and Black sitters. An opportunity sample of participants visiting a gallery in Liverpool viewed ten artworks while their eye movements were recorded and completed a set of individual difference measures. The individual difference measures indicated self-report of art interest, social contact and individuating experience with both Black and White communities, and implicitly held racial bias. The results showed that, despite viewing the paintings for less time, the majority of participants reported paintings showing Black sitters as more interesting, emotionally moving, and pleasurable then those depicting White sitters. However, if a participant reported limited social contact with Black community, and a negative implicit racial bias against them, their rating of aesthetic merit of paintings showing Black sitters was reduced, viewing time increased, and fixations became more focused on faces. The influence of social factors on the viewing of paintings showing White sitters was limited to aesthetic rating. The results are discussed in terms of how social factors influence eye movements when viewing paintings in a real-world setting.

Achieving high-thermal-conductivity brazed joint between carbon-based composites and Mo-Cu alloys by increasing the heat transfer area

Carbon-fiber-reinforced carbon matrix (Cf/C)-Mo30Cu brazed joints play an important role in the cooling systems of thermonuclear reactors. However, the limited contact area of heterogeneous interfaces severely limits the heat transfer efficiency. To overcome this drawback, we prepare three-dimensional porous interfaces by pre-oxidizing the Cf/C composite. Results show that circular gaps are formed between the carbon fibers and the pyrolyzed carbon after pre-oxidization at 600 °C in air. Fster braze penetration in the Cf/C composite is achieved, and the heat-transfer area across the interface is dramatically increased. The room-temperature thermal conductivity of the joints reaches a maximum value of 146 W·m−1·K−1 at a pre-oxidation time of 2 min; this value is 30 % higher than that obtained without treatment. The enhancement in thermal conductivity is mainly attributed to the increased contact area at the interface between the brazing seam and the Cf/C matrix, which provides more channels for heat transfer. This method of significantly improving the thermal conductivity is an important guide for the thermal management of thermonuclear reactors.

Supramolecular assemblies with aggregation-induced emission for in situ active imaging-guided photodynamic therapy of cancer cells

Photodynamic therapy (PDT) has attracted widespread attention as a novel non-invasive anticancer approach. However, the diminished photosensitivity and limited oxygen exposure caused by the aggregation of traditional photosensitizers greatly impair its overall therapeutic efficacy. Herein, a series of water-soluble aggregation-induced emission luminogens (AIEgens) with triphenylamine as skeleton were synthesized and exhibited bright Near-infrared (NIR) emission and strong reactive oxygen species (ROS) generation. Through host-guest complexation between the multicharged triphenylamine units on AIEgens and cucurbit[10]uril (CB[10]) host molecule, supramolecular nanoassemblies were constructed and exhibited negligible phototoxicity to normal cells due to their limited oxygen contact. In contrast, the efficient release of AIEgens from nanoassemblies through competitive binding of overexpressed peptides in cancer cells with CB[10], enabled the full exploitation of the photosensitivity of AIEgens to produce highly efficient ROS, achieving selective ablation of cancer cells. Moreover, due to the restriction of intramolecular motion (RIM) upon anchored on organelle membranes through electrostatic interactions, the cationic AIEgens with weak fluorescence in physiological environment exhibited intense fluorescence emission, thus realizing imaging-guided PDT. This work may open up an avenue for the development of simple and feasible smart responsive nanomaterials for cancer treatment using supramolecular host-guest complexation strategy.

Controllable synthesis of TiO2/graphene composites for human voice recognition in strain sensor.

Low-dimensional materials have demonstrated strong potential for use in diverse flexible strain sensors for wearable electronic device applications. However, the limited contact area in the sensing layer, caused by the low specific surface area of typical nanomaterials, hinders the pursuit of high-performance strain-sensor applications. Herein, we report an efficient method for synthesizing TiO2-based nanocomposite materials by directly using industrial raw materials with ultrahigh specific surface areas that can be used for strain sensors. A kinetic study of the self-seeded thermal hydrolysis sulfate process was conducted for the controllable synthesis of pure TiO2 and related TiO2/graphene composites. The hydrolysis readily modified the crystal form and morphology of the prepared TiO2 nanoparticles, and the prepared composite samples possessed a uniform nanoporous structure. Experiments demonstrated that the TiO2/graphene composite can be used in strain sensors with a maximum Gauge factor of 252. In addition, the TiO2/graphene composite-based strain sensor showed high stability by continuously operating over 1,000 loading cycles and aging tests over three months. It also shows that the fabricated strain sensors have the potential for human voice recognition by characterizing letters, words, and musical tones.