This paper studies the effects of government land regulations (GLR) on housing supply elasticity in urban China. We first extend the theoretical framework of Saiz (2010), then use land transaction ...microdata, satellite‐generated data, and the construction of instrumental variables to analyze the marginal effect of GLR, and finally calculate the housing supply elasticity caused by GLR. Our analysis finds that GLR is an important reason for the overall inelasticity of housing supply in 272 Chinese cities, which reduces housing supply elasticity from 1.457 (elastic) to 0.872 (inelastic). Housing supply elasticity caused by GLR has declined the most in first‐tier cities and the eastern regions. The marginal effect of land use regulation is greater than that of land allocation and supply regulations. The initial development level and natural geographic constraint of each city also matter in China's housing supply market.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Carbon dioxide (CO2) is an available, abundant, and renewable C1 resource, which could be converted into value-added chemicals. Due to its inherent thermodynamic stability and kinetic inertness, it ...is difficult to realize its efficient utilization. Nevertheless, many elegant strategies for the utilization of CO2 have been developed using Lewis bases, frustrated Lewis pairs, hydroxyl-containing compounds, amino-group-containing compounds or transition metal catalysis. Among them, base-mediated carboxylation of C-nucleophiles is an environmentally friendly strategy for CO2 conversion, which is operationally simple, using low-toxicity bases and economical available promoters, without the use of complex ligands or cocatalysts. This review summarizes related work on the base-mediated carboxylation of C-nucleophiles with CO2, based on the effects of nucleophiles, promoters, additives, and solvents. The types of pronucleophile are categorized as follows: hydrocarbon with C(sp3)–H, C(sp2)–H or C(sp)–H bonds, organosilanes, organotin, organoboron, and N-tosylhydrazones. Typical mechanisms and applications of these carboxylation reactions are also depicted. Moreover, mechanistic comprehension of CO2 activation and conversion at a molecular level aims to further expand the repertoire of carboxylation transformations mediated by bases.
No convenient, inexpensive, and non-invasive screening tools exist to identify pulmonary hypertension (PH) - left heart disease (LHD) patients during the early stages of the disease course. This ...study investigated whether different methods of lung ultrasound (LUS) could be used for the initial investigation of PH-LHD.
We conducted a single-center prospective observational study at the Zigong Fourth People's Hospital. We consecutively enrolled patients with heart failure (HF) admitted to the emergency intensive care unit from January 2018 to May 2020. Transthoracic echocardiography and LUS were performed within 24 h before discharge. We used the Spearman coefficient for correlation analysis between ultrasound scores and pulmonary arterial systolic pressure (PASP). Bland-Altman plots were generated to inspect possible bias, and receiver operating characteristic (ROC) curves were calculated to assess the relationship between ultrasound scores and an intermediate and high echocardiographic probability of PH-LHD.
Seventy-one patients were enrolled in this study, with an overall median age of 79 (interquartile range: 71.5,84.0) years. Among the 71 patients, 36 (50.7%) cases were male, and 26 (36.6%) had an intermediate and high echocardiographic probability of PH. All four LUS scores in patients with an intermediate and high probability of PH were significantly higher than in patients with a low probability of PH (P <0.05). The correlation coefficient (r) between different LUS scoring methods and PASP was moderate for the 6-zone (r=0.455, P <0.001), 8-zone (r=0.385, P=0.001), 12-zone (r=0.587, P <0.001), and 28-zone (r=0.535, P <0.001) methods. In Bland-Altman plots, each of the four LUS scoring methods had a good agreement with PASP (P <0.001). The 8-zone and 12-zone methods showed moderately accurate discriminative values in differentiating patients with an intermediate and high echocardiographic probability of PH (P <0.05).
LUS is a readily available, inexpensive, and risk-free method that moderately correlates with PASP. LUS is a potential screening tool used for the initial investigation of PH-LHD, especially in emergencies or critical care settings.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
This study aimed to compare the visual outcomes of the first operated eyes with those of the second operated eyes following small-incision lenticule extraction (SMILE).
A total of 202 patients (404 ...eyes) underwent SMILE using the tear film mark centration method for myopia and myopic astigmatism correction. Baseline characteristics, objective optical quality, decentered displacement, induced corneal aberrations, and modulation transfer function (MTF) values were assessed. Linear regression analyzed the relationship between decentration and visual quality parameters, including corneal aberrations and MTF values.
No significant difference was observed in objective visual quality, efficacy, and safety indexes between the two groups (all P > 0.05). The average decentered displacement for the first and second surgical eyes was 0.278 ± 0.17 mm and 0.315 ± 0.15 mm, respectively (P = 0.002). The horizontal coma in the first surgical eyes were notably lower than in the second (P = 0.000). MTF values at spatial frequencies of 5, 10, 15, and 20 cycles/degree (c/d) were higher in the first surgical eyes compared to the second (all P < 0.05). Linear regression indicated that high-order aberrations (HOAs), root mean square (RMS) coma, spherical aberration, horizontal coma, vertical coma, and eccentric displacement were all linearly correlated. Furthermore, MTF values exhibited a linear relationship with eccentric displacement across these spatial frequencies.
There was no discernible difference in visual acuity, efficacy, or safety between the two operated eyes. Nonetheless, the first operated eyes exhibited reduced decentered displacement and demonstrated superior outcomes in terms of horizontal coma and MTF values compared to the second operated eyes following SMILE. The variations in visual quality parameters were linearly correlated with decentered displacement.
Carbon dioxide (CO
2
) is an available, abundant, and renewable C1 resource, which could be converted into value-added chemicals. Due to its inherent thermodynamic stability and kinetic inertness, it ...is difficult to realize its efficient utilization. Nevertheless, many elegant strategies for the utilization of CO
2
have been developed using Lewis bases, frustrated Lewis pairs, hydroxyl-containing compounds, amino-group-containing compounds or transition metal catalysis. Among them, base-mediated carboxylation of
C
-nucleophiles is an environmentally friendly strategy for CO
2
conversion, which is operationally simple, using low-toxicity bases and economical available promoters, without the use of complex ligands or cocatalysts. This review summarizes related work on the base-mediated carboxylation of
C
-nucleophiles with CO
2
, based on the effects of nucleophiles, promoters, additives, and solvents. The types of pronucleophile are categorized as follows: hydrocarbon with C(sp
3
)-H, C(sp
2
)-H or C(sp)-H bonds, organosilanes, organotin, organoboron, and
N
-tosylhydrazones. Typical mechanisms and applications of these carboxylation reactions are also depicted. Moreover, mechanistic comprehension of CO
2
activation and conversion at a molecular level aims to further expand the repertoire of carboxylation transformations mediated by bases.
Carbon dioxide (CO
2
) is an available, abundant, and renewable C1 resource, which could be converted into value-added chemicals.
Carbon dioxide (CO 2 ) is an available, abundant, and renewable C1 resource, which could be converted into value-added chemicals. Due to its inherent thermodynamic stability and kinetic inertness, it ...is difficult to realize its efficient utilization. Nevertheless, many elegant strategies for the utilization of CO 2 have been developed using Lewis bases, frustrated Lewis pairs, hydroxyl-containing compounds, amino-group-containing compounds or transition metal catalysis. Among them, base-mediated carboxylation of C -nucleophiles is an environmentally friendly strategy for CO 2 conversion, which is operationally simple, using low-toxicity bases and economical available promoters, without the use of complex ligands or cocatalysts. This review summarizes related work on the base-mediated carboxylation of C -nucleophiles with CO 2 , based on the effects of nucleophiles, promoters, additives, and solvents. The types of pronucleophile are categorized as follows: hydrocarbon with C(sp 3 )–H, C(sp 2 )–H or C(sp)–H bonds, organosilanes, organotin, organoboron, and N -tosylhydrazones. Typical mechanisms and applications of these carboxylation reactions are also depicted. Moreover, mechanistic comprehension of CO 2 activation and conversion at a molecular level aims to further expand the repertoire of carboxylation transformations mediated by bases.
Harvesting energy from rotational motion for powering low-power electrical devices is attracting increasing research interest in recent years. In this paper, a magnetic-coupled buckled beam ...piezoelectric rotation energy harvester (MBBP-REH) with bistable and frequency up-conversion is presented to harvest low speed rotational energy with a broadband. A buckled beam attached with piezoelectric patches under dynamical axial load enables the harvester to achieve high output power under small excitation force. The electromechanical coupling dynamical model is developed to characterize the MBBP-REH. Both the simulations and experiments are carried out to evaluate the performance of the harvesters in various conditions under different excitations. The experimental results indicate that the proposed harvester is applicable for low speed rotation and can generate stable output power under wideband rotating excitation. For the harvester with two magnets that produce attractive forces with the center magnet of the buckled beam, the average power is 682.7 μW and the maximum instantaneous power is 1450 μW at 360 r/min.
To measure the anterior and posterior ocular biometric characteristics concurrently and to determine the relationship between the iris and choroid in healthy Chinese subjects.
A total of 148 subjects ...(270 eyes) were enrolled in this cross-section study. The anterior and posterior ocular biometric characteristics were measured simultaneously by anterior segment optical coherence tomography (AS-OCT) and swept-source optical coherence tomography (SS-OCT).
Compared with male eyes, female eyes had narrower anterior biometric parameters that presented with smaller anterior segment parameters including anterior chamber depth (ACD), width (ACW), area (ACA), and volume (ACV); (all p<0.001), narrower anterior chamber angle parameters including angle opening distance (AOD750), trabecular-iris space area (TISA750), and angle recess area (ARA); (all p<0.001), higher iris curvature (ICURV) (p = 0.003), and larger lens vaults (LV) (p = 0.019). These anterior ocular biometric parameters were correlated with increasing age (p<0.01). Iris thickness (IT750) and iris area (IAREA) were associated with age, ACW, and pupil diameter (all p<0.05), while choroidal thickness (CT) was associated with age, gender, and axial length (all p<0.05). Univariate regression analysis showed that greater CT was significantly associated with smaller IAREA (p = 0.026).
Compared with male eyes, female eyes had narrower anterior biometric parameters that correlated with increasing age, which would be helpful in explaining the higher prevalence of angle closure rates in the female gender and in aging people. Increased CT might be associated with smaller iris area; however, this possibility needs to be investigated in future studies before this conclusion is made.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The COVID-19 pandemic seriously threatened human survival and development. It has also highlighted the significant correlation between ecological and public health. After three years of the COVID ...pandemic, Chinese consumers have become more aware of the importance of health. Especially in the Internet era, consumers' purchasing methods and health awareness have been changed. Consumers can buy nutritious and organic foods. To understand the impact of consumer psychology and health beliefs on the willingness to purchase organic food in the post-pandemic period, this study uses organic beef as an example and extracts key variables from three basic theories. The three basic theories include the Health Belief Model (HBM), the Theory of Planned Behavior (TPB), and the Norm Activation Model (NAM), respectively. Specifically, perceived susceptibility and severity are combined to form a health belief variable that can drive organic food purchasing. In contrast, perceived benefit, moral norms, self-efficiency, and controllability are introduced as mediating variables to construct the health driving factors of organic beef purchasing. Structural equation modeling (SEM) and mediation effect tests are used to analyse 539 samples. Meanwhile, paths and mechanisms between health concern and other variables are explored. The results show that health concern is an important driving factor. Health concern can significantly promote the formation of willingness to purchase organic beef. Mediation effect tests suggest that health concern can indirectly affect the willingness to purchase organic beef through perceived benefit, moral norms, and controllability, but the mediation effect of self-efficiency is not significant. This study provides important references for government regulation and certification of organic foods as well as for enterprises'organic food marketing strategies.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
SAPO-11 molecular sieves were modified with different Ni contents by the
in situ
modification method. The Ni-modified SAPO-11 molecular sieves were used as the supports to prepare the corresponding ...NiW-supported catalysts for the hydroisomerization of n-hexadecane. The Ni-modified SAPO-11 and the corresponding NiW-supported catalysts were characterized by X-ray diffraction, scanning electron microscopy, N
2
adsorption–desorption, NH
3
-temperature-programmed desorption, pyridine adsorbed infrared, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy. The results showed that Ni
in situ
modification preserved the crystal structure of SAPO-11; increased the BET specific surface area, mesopore volume, and medium and strong Brønsted acid amount of SAPO-11; and increased the stacking number of the active phase of the catalysts. 3Ni-SAPO-11 possessed the largest BET specific surface area, mesopore volume, and medium and strong Brønsted acid amount. NiW/3Ni-SAPO-11 possessed the highest dispersion of the active phase and the highest sulfidation degree of the active metals. The results of the hydroisomerization of n-hexadecane showed that Ni
in situ
modification improved the catalytic activity and selectivity of the catalysts for the hydroisomerization of n-hexadecane to varying degrees. Especially, NiW/3Ni-SAPO-11 had the highest catalytic activity and isomer selectivity, and the maximum yield of isomeric hexadecane could reach 71.18%.
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