Search

The development of intrinsically stretchable polymer semiconductor holds substantial promise in the field of wearable electronics. However, charge transport mobility is typically compromised in existing stretchable semiconductors to achieve the desired stretchability. Herein, a novel "regional conjugation" strategy is proposed to design an intrinsically stretchable polymer semiconductor oligo‐diketopyrrolopyrrole‐thieno[3,2‐b]thiophene (DPPTT)–urethane, in which oligo‐DPPTT conjugated units and alkyl urethane nonconjugated units are introduced. The regional conjugation of oligo‐DPPTT in the polymer backbone endows DPPTT–urethane with good molecular packing, leading to a high mobility of up to 1.7 cm2 V−1 s−1. Additionally, incorporating alkyl urethane nonconjugated units in the backbone can reduce film crystallinity and chain aggregation, which contribute to the stretchability of the polymer thin film. Consequently, fully stretchable transistors retain carrier mobility even at 100% biaxial tensile strain. Furthermore, the fully stretchable organic field‐effect transistor arrays show remarkable charge transport reversibility and durability after 1000 stretch–release cycles at 25% strain. Additionally, the device exhibits extraordinary electrical stability in air atmosphere. Overall, these results indicate that the "regional conjugation" strategy provides an effective and promising methodology to design intrinsically stretchable and high‐performance polymer semiconductor that can advance the development of soft and wearable electronics. [ABSTRACT FROM AUTHOR]

Surgical resection is the preferred option for hepatocellular carcinoma (HCC), but surgical navigation technology using indocyanine green still has some drawbacks such as non‐specific imaging, thus it is very important to develop new fluorescence imaging technology. All‐cis hexaphenyl‐1,3‐butadiene derivative (ZZ‐HPB‐NC) with aggregation‐induced emission (AIE) feature has been reported to be quickly turned‐on fluorescent response in the intraoperative frozen‐section slides of HCC. However, the probe did not respond to normal liver tissue around HCC. In order to enhance the diagnostic rate and elucidate the response mechanism, all‐trans configuration EE‐HPB‐NC, was furtherly synthesized. Within two minutes, non‐cancer tissues could be fluorescently labeled by EE‐HPB‐NC by spraying, showing the same effect with ZZ‐HPB‐NC to HCC. The results indicated that the configuration‐induced cross‐identification fluorescence imaging strategy was achieved through the combination of ZZ‐ and EE‐HPB‐NC. Then the mechanism of HPB‐NC localization in HCC lesions was explored, and the binding of HPB‐NC with specific proteins in cells resulted in the AIE effect to label HCC cells. On this basis, the accuracy of specific fluorescence imaging for HCC was further verified on the mouse hepatic neoplasm models, indicating that it has clinical application potential for surgical fluorescence real‐time navigation. [ABSTRACT FROM AUTHOR]

Objective To characterize the epidemiological features of public health emergencies that occurred in Changping District of Beijing City in recent years, to provide scientific support for promoting prevention and control levels and strengthening response capability on such episodes. Methods Public health emergencies and related information reported in Changping District (January 2006 to December 2023) were obtained from the National Public Health Emergency Reporting and Management System. A descriptive epidemiological analysis was conducted on factors such as event level, type, and temporal and spatial distribution in the emergency episodes. Results From 2006 to 2023, a total of 1 219 public health emergencies were reported in Changping District (an annual average of 68 incidents), involving 2,097 cases (an annual average of 117 cases), showing an overall decreasing trend in the annual number of incidents. The emergencies were mainly classified as general level (Class IV, 31 incidents, all infectious disease events) and unclassified events (1 183 incidents, including 1 141 non-occupational carbon monoxide poisoning episodes and 34 infectious disease episodes); there were no major level (Class III), significant level (Class II), or particularly significant level (Class I) public health emergencies. Non-occupational carbon monoxide poisoning accounted for the highest proportion of public health emergencies, occurring predominantly in winter months (November to March), with incidents mainly occurring in households (1 091, 95.62%). Infectious disease emergencies mainly emerged in February and summer months (June to August), with incidents mainly occurring in households (42 cases, 60.00%) and schools (25 cases, 35.71%), involving diseases such as cholera, chickenpox, type A influenza (H1N1), and novel coronavirus infection. Meanwhile, the emergencies were mostly located in the streets/towns with higher population density and larger numbers of floating populations, such as Huilongguan Street, Dongxiaokou Street, Beiqijia Street, and Shahe Town. The median reporting time for public health emergencies in Changping District during 2006-2023 was 0.29 days, with a positive correlation between the discovery-to-reporting time and the duration of infectious disease outbreaks (rs=0.429, P<0.01). Conclusions Non-occupational carbon monoxide poisoning and infectious disease outbreaks are the major causes as well as priorities of public health emergencies in Changping District. The urban-rural fringe areas are high-risk and key areas for the management of such emergencies. For public health emergencies caused by cholera, chicken pox, novel coronavirus infection, and other infectious diseases, comprehensive measures such as strengthening epidemic monitoring, expanding vaccination coverage, and improving handling capacity should be taken to enhance the response capability and raise the prevention and control level on such emergencies. [ABSTRACT FROM AUTHOR]

Natural vegetation protects, maintains, and improves the environment through its ecological functions and is, thus, an important component of Earth's ecosystems. The distribution of natural vegetation and its corresponding ecological roles vary with the topographic gradient. Understanding this role is essential for effective ecosystem management and conservation efforts. This study analyzes vegetation composition across altitude gradients and the spatiotemporal evolution of water conservation, soil conservation, and carbon storage in the southern hill and mountain belt of China. We then explored the drivers of the ecological functions of vegetation at different altitude gradients. The results showed that water conservation increased by 108.56%, soil conservation increased by 97.04%, and carbon storage increased only slightly. The ecological functions of vegetation varied across altitude gradients, with the 500–800 m gradient exhibiting markedly higher ecological functions than the other gradients. The effect of precipitation on soil conservation increases with altitude. In addition, at higher altitudes, evergreen coniferous forests had a greater effect on carbon storage. Based on the results, we propose vegetation management measures for different altitudes. This study provides a reference for decision-makers to develop and adjust ecological restoration programs in mountainous areas for the improvement of the local ecological environment. [ABSTRACT FROM AUTHOR]

Affected by the near-fault pulse-like ground motions, the tunnels emerged in adverse geology, especially in an inhomogeneous strata are more vulnerable. However, the quantitative index effects on tunnel response during pulse identification are unclear and the propagation features of the near-fault pulse-like waves in a soft soil interlayer site are seldom revealed. In view of this, an improved energy-based pulse identification was used in this study to quantitatively extract the potential pulse energies emerged in velocity time-histories of ground motions. Subsequently, a series of numerical simulations were carried out to consider the critical parameters of soft soil layer and input ground motions. Finally, the dynamic response of the tunnel and interaction differences of soil and tunnel subjected to three types of ground motions were revealed. The result showed that the near-fault pulse-like ground motions pose a commonly severe damage to the tunnel, especially in the high pulse period ground motions based on the energy-based pulse identification method. The pulse energy of ground motions is an effective pulse index to analyze the seismic effects on tunnel when pulse periods of two different ground motions are uniform, and the index affects the tunnel in dynamic internal forces. More importantly, the existence of soft soil layer severely affects the propagation of input ground motions. At frequency domain, the ground response increases at high frequency component in the near-fault pulse-like ground motion, while the response shows a decreasing at low frequency component. [ABSTRACT FROM AUTHOR]

Layered double hydroxide (LDH) is frequently used for phosphate removal in water, while a desirable LDH adsorbent should have sufficiently high adsorption capacity and selectivity. To enhance the removal performance and selectivity of phosphate by LDH, La-doped layered double hydroxide/biochar (La–MgAl–LDH/BC) was synthesized by using a co-precipitation method. Investigation results showed that lanthanum (La) metal loading can significantly enhance the phosphate adsorption performance of La–MgAl–LDH. Then, the introduction of La–MgAl–LDH into BC improved the adsorption capacity of phosphate by the adsorbent, which is 1.8 times that of pure La–MgAl–LDH. The optimum La to Al molar ratio was 0.2 : 0.8 in La–MgAl–LDH materials, and the La–MgAl–LDH to BC mass ratio was 9.3 : 10. Furthermore, both La–MgAl–LDH and La–MgAl–LDH/BC exhibited an enhanced ability to resist interference from co-existing anions (Cl−, SO42−, NO3− and CO32−) compared to LDH. For batch experiments, the kinetic results indicated that the adsorption process of phosphate by La–MgAl–LDH/BC follows a pseudo-second-order kinetics model, reaching equilibrium quickly within 1 h. Furthermore, film diffusion and intra-particle diffusion simultaneously took place. The maximum monolayer phosphate adsorption capacity of La–MgAl–LDH/BC could reach 249.3 mg PO43− g−1 (513.6 mg PO43− g−1, converting to an equivalent La–MgAl–LDH). After four cycles, La–MgAl–LDH/BC showed good reusability, and over 63.5% of phosphate uptake was retained with minimal metal leaching. Additionally, phosphate could be rapidly removed from actual water and simulated water at low concentrations. The electrostatic attraction, ligand exchange, ion exchange and Lewis acid action jointly facilitate the adsorption of phosphate. [ABSTRACT FROM AUTHOR]