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To understand the temporal variation, spatial distribution and factors influencing the public’s sensitivity to air pollution in China, this study collected air pollution data from 2210 air pollution monitoring sites from around China and used keyword-based filtering to identify individual messages related to air pollution and health on Sina Weibo during 2017–2021. By analyzing correlations between concentrations of air pollutants (PM2.5, PM10, CO, NO2, O3 and SO2) and related microblogs (air-pollution-related and health-related), it was found that the public is most sensitive to changes in PM2.5 concentration from the perspectives of both China as a whole and individual provinces. Correlations between air pollution and related microblogs were also stronger when and where air quality was worse, and they were also affected by socioeconomic factors such as population, economic conditions and education. Based on the results of these correlation analyses, scientists can survey public concern about air pollution and related health outcomes on social media in real time across the country and the government can formulate air quality management measures that are aligned to public sensitivities.

Sandwich insulation wall panels (SIWPs) are used extensively as thermal resistance components in buildings. Connectors in SIWPs are subjected to axial and shear forces to resist the load o...

High-strength Engineered Cementitious Composite (HSECC) usually features with low water-to-binder ratio (W/B) and low sand-to-binder ratio (S/B), for obtaining expected workability, mechanical property and multi-crack behavior. However, the low W/B and low S/B of HSECC can cause high shrinkage, which will jeopardize its volume stability and durability. In this paper, the influence of W/B and S/B on HSECC volume stability including chemical shrinkage, autogenous shrinkage and drying shrinkage, mechanical properties including compressive strength, tensile strength, tensile strain and tensile strain energy were investigated. Experiment results showed that in the W/B range of 0.13–0.24, S/B range of 0.3–0.9, the magnitude of chemical shrinkage overwhelms autogenous shrinkage and drying shrinkage; meanwhile, along with the increase of W/B and S/B, the total shrinkage is lowed and the magnitude of autogenous shrinkage tends to be comparable with drying shrinkage. In the W/B range of 0.13–0.24, along with the increase of S/B from 0.3 up to 0.8, the compressive strength and tensile strength was enhanced, however, the ductility of HSECC was lowed especially when S/B was greater than 0.6; when S/B was enhanced to 0.9, all the mechanical properties and ductility was severely injured. So, the optimum S/B of HSECC should be decided by systematically considering its influence on volume stability, mechanical strength and ductility.

The flat slab is a preferred choice for structural design because of its architectural and construction efficiency. However, flat slabs collapse frequently because of brittle punching shear failure of RC slab-column connections, which can be attributed to the low tensile strength and high tensile brittleness of conventional concrete. Engineered cementitious composites (ECC) have excellent tensile properties compared with conventional concrete. The failure modes of reinforced-ECC (RECC) slab-column connections were revealed in a recently published study by authors. In this study, three RC slab-column connections were tested further monotonically in a comparative study of RECC specimens. A specimen with a slab span of 700 mm and the reinforcement ratio of ρ = 0.6% and 1.4%, and a 500-mm span specimen with a ρ = 1.4% were used. The peak and residual specimen strengths were estimated and compared with the test results. The main conclusions were: (1) the punching shear failure of the RECC specimens was delayed significantly compared with the RC specimens. The RECC specimens experienced a flexural-triggered punching shear failure, with ductility ratios from 2.4 to 6.4, whereas the RC specimens usually have zero ductility. (2) The peak RECC specimen load was ~2.0 times greater than that of the RC among the tested specimens. The peak strength of the RECC specimens was estimated by a yield-line mechanism, whereas the peak strength of the RC specimens was estimated by the punching shear-resisting mechanism. (3) The residual RECC load was ~3.0 times greater than that of the RC among the tested specimens. The main contribution to the residual strength of the RECC specimens was by the vertical compound of axial force from steel bars that passed through the punching shear cone. The main contribution to the residual strength of the RC specimens was by the concrete cover spalling strength. (4) The comparative study verified preliminarily the feasibility of improving the punching shear performance by using ECC in slab-column connections.

RC flat-slab is widely regarded as one of the mainstream design solutions in commercial engineering projects due to its flexibility and the characteristic of maximization of floor-to-floor height. However, RC slab-column connections are vulnerable to punching shear failure due to the brittle tensile behavior of standard concrete. Engineered cementitious composites (ECC) have greater ductility than standard concrete which makes it ideal for slab-column connections. In this study, five RECC slab-column connections, which have different reinforcement ratios (ρ) and span ratios (λ), were tested under concentric gravity load to investigate their failure behaviors. Reinforcement ratios of ρ = 0.2%, 0.6%, 1.4% and 2.3%, as well as span ratios of λ = 8.4 and 5.7 were considered. Flexural strengths V flex of specimens were estimated based on yield-line theory, and punching shear strengths V pun of specimens were estimated by empirical formulas of ACI and JSCE codes. The main conclusions obtained in this study are as follows: (1) At a fixed span ratio of λ = 8.4, specimen with ρ = 0.2% experienced premature flexural failure after yielding reinforcement, while specimens with ρ = 0.6% and 1.4% both experienced flexural-triggered punching shear failure. In addition, premature punching shear failure occurred in ρ = 2.3% specimen. For specimens with λ = 5.7 and ρ = 1.4%, the flexural-triggered punching shear failure was also exhibited. (2) The ductility ratios of specimens with flexural-triggered failure modes (i.e. premature flexural failure and flexural-triggered punching shear failure) varied from 1.63 to 6.4. Premature flexural failure has the lowest ductility ratio of 1.63 amongst the flexural-triggered failure modes. Additionally, punching shear failure has the lowest ductility ratio of all the failure modes, which is close to 1.0. (3) The lesser of V flex and V pun was adopted as the estimated ultimate load, the errors between the test results and the estimated values are within 15%. (4) Flexural-triggered failure modes or strong-shear-weak-bending design can be achieved by making V pun > V flex through restricting the maximum reinforcement ratio. Premature flexural failure can be avoided by limiting the minimum reinforcement ratio.

Prefabricated reinforced concrete (PC) shear walls are widely used because of their convenience of construction. Diverse forms of wall joints for assembling precast shear walls were studied in the recent decade. However, during the assembly of mutually perpendicular precast shear walls, it is difficult to satisfy joint strength requirements. In this study, an H-shaped Shear Key (HSK) with welding connections was proposed for the connection of mutually perpendicular precast shear walls. Quasi-static cyclic loadings were conducted to test the seismic properties of HSK specimens with different welding configurations. The strength, energy dissipation capacity and fatigue properties of specimens were compared. Image measurement was adopted to measure the damage patterns and crack dimensions. The test results validated the effectiveness of the HSK specimens and appropriate configurations of HSKs are recommended for practical engineering applications.

Prefabricated reinforced concrete shear walls are widely used because of their stiffness, strength and convenient form of construction, despite their low ductility and energy dissipation capacity. For ease of transport, large shear walls are commonly divided into smaller sections and assembled on site. Steel shear keys (SSKs) can replace wet joints connecting the wall sections while increasing the ductility and energy dissipation of shear wall systems. Here, we present an improved SSK design and a practical installation method for connecting shear walls. The SSK shape is optimized through an Improved Simulated Annealing method to enhance the cycle fatigue performance. Fillet welding and plug welding are combined to save the installation space and delay the out-of-plane buckling. Quasi-static cyclic tests were performed to investigate the SSKs with the welded connection, which exhibited satisfactory energy dissipation capacity. The combined welding method provided a strong SSK–wall connection while significantly delaying out-of-plane buckling.

To better understand the relationship between salinity and the carbon stable isotope composition (expressed as δ13C) of mangrove plants and to test whether the patterns of variation in δ13C of mangrove plants differ from those of nonhalophytes as response to salinity, the effect of salinity on leaf δ13C in two dominant mangrove species, Aegiceras corniculatum and Kandelia candel, was studied. Furthermore, to determine whether the variation in δ13C of mangrove species is adjusted by stomatal conductance, K. candel was selected as an example, and leaf gas-exchange characteristics of the seedlings were measured. It was observed that both mangrove species had a lower leaf δ13C under their optimum salinity (1.50% for Ae. corniculatum and 2.00% for K. candel). This variation in δ13C of mangrove plants was attributable largely to stomatal adjustment as for nonhalophytes in which a strong correlation between δ13C and relevant photosynthetic properties is observed. This result suggests that the different response pattern in δ13C was a consequence of the variation in stomata in relation to the different tolerance to salinity. The optimum salinity inferred by leaf δ13C provides a feasible method for comparing salt tolerance between mangrove plants belonging to different species, which is useful for mangrove restoration.

To test whether the values of delta13C in mangrove plants are affected by Cd application, the seedlings of Aegiceras corniculatum, a dominant mangrove species, were cultured in soil supplied with CdCl2 solution at the concentration of 0, 0.5, 2.5, 5, 20, 30 and 50 CdCl2 mg/kg wet soils. Plants were grown in 10 replicate pots with 5 propagules each. After 5 months of Cd exposure, three pots contained 15 seedlings with average shoot heights were selected for each treatment. Leaves and roots of seedling were sampled respectively and analyzed for delta(13)C. Growth traits (fresh weight, shoot height and root length), total chlorophyll content, and Cd concentrations in leaf, root and dry soil were determined. After 5 months of the seedling growth, the concentrations of Cd in dry soil were 0.47, 0.83, 2.77, 4.54, 18.89, 29.79 and 47.35 mg/kg respectively. The values of delta13C in roots and leaves were affected to some extent by Cd application. Although root delta(13)C showed more sensitive to Cd compared with leaves, the values of delta13C in roots were not significantly affected by Cd until Cd level higher than 29.78 mg/kg which was not expected to exist in natural environments. Minor variation in delta13C values observed in roots and leaves was likely due to limited Cd uptake by seedlings and subsequent lack of negative impacts on photosynthesis.

Many previous studies demonstrate that carbon stable isotope composition (usually expressed as isotopic ratio, δ13C) can reflect the integrated response of physiological processes to environment, but little is known of the variation in δ13C of mangrove plants as affected by salinity, especially in response to long term saline environment. The variation in δ13C of three dominant mangroves growing in long-term saline environments in the field was assessed. Mature leaves of Avicennia marina (Forsk) Vierh., Kandelia candel (L.) Duce., and Aegiceras corniculatum Blanco. were collected at seven sample sites covering seven salinity levels (14.07%–19.83%) at a natural mangrove wetland located in southeast China. The δ13C values varied from −31.46% to −27.33‰ with increasing salinity, reflecting the typical C3 pathway of CO2 fixation. The δ13C was positively related to salinity in K. candel and A. marina, and the reverse was observed in A. corniculatum, even though the correlations were not statistically ...

The present study used functional MRI to clarify the brain regions activated during a series of motor sequencing tasks in healthy volunteers. Ten subjects were scanned while performing three soft signs tasks ranging from simple (PT: palm tapping), moderate (PS: pronation/supination) to complex movements (FEP: fist-edge-palm). The FEP task induced significant activations within the cortical networks including bilateral sensorimotor, SMA, left parietal, and right cerebellum, but no activation in the prefrontal area. Moreover, the percentage signal changes within the left sensorimotor, left thalamus and right cerebellum showed an increase in activation with task complexity. The present findings challenge the traditional belief that FEP was a task for frontal lobe function but suggest that successful performance of more complex neurological soft sign tasks like FEP requires the participation of more brain areas than simple motor sequencing and coordination task like PS and PT. These also provide the empirical data on the neural basis of neurological soft signs for further study in other clinical group like schizophrenia in the near future.

Timolol has been demonstrated to be efficacious in the topical treatment of superficial infantile hemangiomas (IHs). We conducted a prospective study to evaluate the short-term efficacy and safety of timolol in the treatment of superficial IH in Chinese infants. From March to November 2012, 124 patients with superficial IHs were included in the prospective study. The patients were divided into two groups: treatment (101 patients, the timolol drops were administered on the surface of the lesions three times daily, and erythromycin ointment was applied around the lesions) and observation (23 patients, without treatment). The results were categorized into three grades: class 1 (ineffective), class 2 (controlled growth) and class 3 (promoted regression). Within one week of the initiation of timolol treatment, a number of the lesions became softer and lighter in color. Four months following the initiation of timolol treatment, the overall response was class 1 in eight patients (7.9%), class 2 in 36 patients (35.6%) and class 3 in 57 patients (56.4%). Complete tumor regression was observed in 12 patients. No adverse effects were recorded during the treatment period. Among the patients in the observation group, there were 15 class 1 patients (65.2%), seven class 2 patients (30.4%) and only one class 3 patient (4.3%). In conclusion, timolol is an effective and safe treatment for superficial IH. In addition, it may be used in the treatment of proliferative superficial IH, particularly in infants within 6 months of age.

Introduction: To evaluate 1H Magnetic Resonance Spectroscopy (1HMRS) in the diagnosis of hypoxia-ischemic encephalopathy (HIE) of full-term neonates correlated with Magnetic Resonance Imaging (MRI). Materials and methods: Thirty-eight cases of full-term neonates diagnosed as HIE clinically were selected to perform MRI and 1HMRS examination. The ages ranged from 7 to 17 days, with median age of 8.2 days. In which, 26 cases were followed up and/or MRI reexamined at 6 months of age or later. Eight healthy neonates, with no evidence of birth asphyxia, also underwent 1HMRS for comparison. SE sequences were used for routine MR examination; point resolved spectroscopy sequence was required for 1HMRS. The metabolites in the spectra includes: N-acetylaspartate (NAA), choline compounds (CHO), creatine compounds (CR), myo-inositol (MI), lactate (LAC), glutamate and glutamine (Glu–Gln). Results: The peaks of NAA were fall in two cases; the peaks of LAC, which were elevated, appeared as typical double-peaks appearance in 26 cases; the peaks of Glu–Gln, which were also elevated, appeared as zigzag appearance in nine cases. The peaks of CR were decreased in 11 cases, while those of MI were increased in seven cases. Mild type of lesions was present on MRI in 12 cases whose LAC/CR ratio lower than 0.5; mild and moderate types of lesions were present in 15 cases whose LAC/CR ratio between 0.5 and 1.5. Whereas, nine cases of severe lesions and two cases of moderate lesions were present on MRI in 11 cases whose LAC/CR ratio greater than 1.5. Twenty-six of 38 cases were followed up and/or MRI reexamined after 6 months, in which, sequelae were present in 12 cases. Among them, eight cases of sequelae in nine cases whose LAC/CR ratio greater than 1.5 were present (account for 88.89%). Conclusion: 1HMRS plays an important role to diagnose and predict outcome of HIE.

The Fist-Edge-Palm (FEP) task is a motor sequencing task that is widely used in neurological examination. Deficits in this task are believed to reflect impairment in the frontal lobe regions. However, two recent functional brain imaging studies of the FEP task using conventional subtraction analysis failed to demonstrate FEP-induced activation in the prefrontal cortex (PFC), which contradicts existing neuropsychological literature. In this study, psychophysiological interaction (PPI) analysis was used to reanalyze our previous neuroimaging dataset from 10 healthy subjects in order to evaluate the changes of functional connectivity between the sensorimotor cortex and the prefrontal regions during the performances of the FEP task relative to simple motor control tasks. The PPI analysis revealed significantly increased functional connectivity between bilateral sensorimotor cortex and the right inferior and middle frontal cortex during the performance of the FEP task compared with the control tasks. However, regional signal changes showed no significant activation differences in these prefrontal regions. These results provide evidence supporting the involvement of the frontal lobe in the performance of the FEP task, and suggest a role of regulation, rather than direct participation, of the prefrontal cortex in the execution of complex motor sequence tasks such as the FEP task.