Large-Area Fabrication of Ultrathin Metal-Organic Framework Membranes

Metal-organic framework (MOF)-based membranes, featuring potential molecular sieving effects and therefore capable of surmounting the ubiquitous trade-off between membrane selectivity and permeability, hold great promise for multitudinous chemical separations. Nevertheless, it remains highly challenging for the large-area fabrication of ultrathin MOF membranes with variable thickness, great homogeneity, and preferential orientation. Herein, this work reports the facile fabrication of ultrathin (down to 20 nm) NUS-8 membranes in large-area (>200 cm² ) yet with great homogeneity and texture along (00l) direction due to the superior solution processability of the as-synthesized NUS-8 nanosheets. The resultant NUS-8 membranes with good adhesion properties and certain flexibility exhibit excellent rejections (>98% for Mg²⁺ and Al³⁺ , and dyes with molecular weights larger than 585.5 g mol^-1 ) toward aqueous separation of various metal ions and dyes at modest permeance (1-3.2 L m^-2 h^-1 bar^-1 ) due to the well-aligned structures. Such separation performance outstands among polymetric membranes, thin-film composite membranes, mixed matrix membranes, and other MOF membranes reported in the literature. The separation mechanism is reasonably discussed based on the experimental and theoretical results. This study opens up novel perspectives for preparing ultrathin and large-area MOF membranes using the solution processability of MOFs.

[The directionality of measurement bias: a directed acyclic graph-based structural perspective]

Measurement bias (MB) has been described in causal structures but is still not entirely clear. In practice, the correctness of substitution estimate (SE) of effect is a prerequisite for causal inference, usually based on a bidirectionally non-differential misclassification between the measured exposure and the measured outcome. Based on a directed acyclic graph (DAG), this paper proposes a structure for the single-variable measure, where its MB is derived from the choice of an imperfect, "input/output device-like" measurement system. The MB of the SE is influenced both by the measurement system itself and by factors outside the measurement system: while the independence or dependence mechanism of the measurement system still ensures that the MB of the SE is bidirectionally non-differential; however, the misclassification can be bidirectionally non-differential, unidirectionally differential, or bidirectionally differential resulted from the factors outside the measurement system. In addition, reverse causality should be defined at the level of measurement, where measured exposures can influence measured outcomes and vice versa. Combined with temporal relationships, DAGs help elucidate MB's structures, mechanisms, and directionality.

Fe-MOF with U-Shaped Channels for C2H2/CO2 and C2H2/C2H4 Separation

The development of high-performance adsorbents is critical for the low-energy separation of acetylene. Herein, we synthesized an Fe-MOF (MOF, metal-organic framework) with U-shaped channels. The adsorption isotherms of C₂H₂, C₂H₄, and CO₂ show that the adsorption capacity of acetylene is significantly larger than that of the other two gases. Meanwhile, the actual separation performance was verified by breakthrough experiments, indicating the potential to separate C₂H₂/CO₂ and C₂H₂/C₂H₄ mixtures at normal temperatures. Grand Canonical Monte Carlo (GCMC) simulation demonstrates that the framework with U-shaped channels interacts more strongly with C₂H₂ than with C₂H₄ and CO₂. The high C₂H₂ uptake and low adsorption enthalpy highlight Fe-MOF as a promising candidate for C₂H₂/CO₂ separation with a low regeneration energy.

Short-term effects of ambient particulate matter (PM1, PM2.5 and PM10) on influenza-like illness in Guangzhou, China

BACKGROUND

Particulate matter (PM) has been linked to respiratory infections in a growing body of evidence. Studies on the relationship between ILI (influenza-like illness) and PM₁ (particulate matter with aerodynamic diameter ≤1 μm) are, however, scarce. The purpose of this study was to investigate the effects of PM on ILI in Guangzhou, China.

METHODS

Daily ILI cases, air pollution records (PM₁, PM_2.5, PM₁₀ and gaseous pollutants), and metrological data between 2014 and 2019 were gathered from Guangzhou, China. To estimate the risk of ILI linked with exposure to PM pollutants, a quasi-Poisson regression was used. Additionally, subgroup analyses stratified by gender, age and season were carried out.

RESULTS

For each 10 μg/m³ increase of PM₁ and PM_2.5 over the past two days (lag01), and PM₁₀ over the past three days (lag02), the relative risks (RR) of ILI were 1.079 (95% confidence interval [CI]: 1.050, 1.109), 1.044 (95% CI: 1.027, 1.062) and 1.046 (95% CI: 1.032, 1.059), respectively. The estimated risks for men and women were substantially similar. The effects of PM pollutants between male and female were basically equivalent. People aged 15-24 years old were more susceptive to PM pollutants.

CONCLUSIONS

It implies that PM₁, PM_2.5 and PM₁₀ are all risk factors for ILI, the health impacts of PM pollutants vary by particle size. Reducing the concentration of PM₁ needs to be considered when generating a strategy to prevent ILI.

Optimizing pore space of a robust nickel-organic framework for efficient C2H2/C2H4 separation

The separation of acetylene (C2H2) from ethylene (C2H4) is an important but challenging process in the industry because of their similar physical properties and kinetic molecular sizes. Here, we presented...

[Analysis of the whole genome traceability and transmission path simulation experiment of the local cluster COVID-19 epidemic]

Objective: To trace and characterize the whole genome of SARS-CoV-2 of confirmed cases in the outbreak of COVID-19 on July 31, 2021 in Henan Province. Method: Genome-wide sequencing and comparative analysis were performed on positive nucleic acid samples of SARS-CoV-2 from 167 local cases related to the epidemic on July 31, 2021, to analyze the consistency and evolution of the whole genome sequence of virus. Results: Through high-throughput sequencing, a total of 106 cases of SARS-CoV-2 whole genome sequences were obtained. The results of genome analysis showed that the whole genome sequences of 106 cases belonged to the VOC/Delta variant strain (B.1.617.2 clade), and the whole genome sequences of 106 cases were shared with the genomes of 3 imported cases from Myanmar admitted to a hospital in Zhengzhou. On the basis of 45 nucleotide sites, 1-5 nucleotide variation sites were added, and the genome sequence was highly homologous. Conclusion: Combined with the comprehensive analysis of viral genomics, transmission path simulation experiments and epidemiology, it is determined that the local new epidemic in Henan Province is caused by imported cases in the nosocomial area, and the spillover has caused localized infection in the community. At the same time, it spills over to some provincial cities and results in localized clustered epidemics.

[Retraction: Hydrogen alleviates collagen-induced arthritis (CIA) in mice by inhibiting IL-22 levels]

The retraction has been discussed after the authors asked to retract this article due to incorrect attribution and affillation of the authors.

[Analysis of epidemiological characteristics of bacillary dysentery with multiple-onset in Henan Province from 2005 to 2020]

Objective: To understand the epidemiological characteristics of bacillary dysentery with multiple-onset in Henan province from 2005 to 2020. Methods: The reported cases of bacillary dysentery (including confirmed cases and clinically diagnosed cases) in Henan Province from January 2005 to December 2020 were collected through China's National Disease Supervision Information Management System. The main information included gender, age, home address, date of onset and date of diagnosis. The interval between two episodes of the same case was more than 15 days, which was judged as two episodes. The incidence characteristics of bacillary dysentery patients with two or more cases in Henan Province from 2005 to 2020 were analyzed, and the regional distribution map of cases was drawn using ArcGIS software. Results: From 2005 to 2020, a total of 250 430 cases of bacillary dysentery were reported in Henan Province, with a cumulative incidence rate of 228.66/100 000. There were 2 342 cases with two or more attacks. The incidence of recurrent cases of bacillary dysentery increased year by year (χ²_trend=2 932.28, P<0.001). There was no significant difference in the incidence of two or more cases of different sexes (χ²=0.39, P=0.540). There was significant difference in the incidence among different age groups (χ²=438.40, P<0.001). The incidence of two or more cases in the 60-69 age group was relatively high (1.70%). The shortest time interval between the onset of the disease was 16 days, and the longest was 5 579 days, with M (Q₁, Q₃) about 428 (237, 843) days. Compared with healthy people, those with a history of bacterial diseases had a higher risk of developing bacillary dysentery (RR: 4.12, 95%CI: 3.95‒4.29). Conclusion: The proportion of patients with multiple-onset shows an increasing trend, and there is an age difference.

Being small for gestational age is not an independent risk factor for mortality in neonates with congenital diaphragmatic hernia: a multicenter study

BACKGROUND

Congenital diaphragmatic hernia (CDH) accounts for 8% of all major congenital anomalies. Neonates who are small for gestational age (SGA) generally have a poorer prognosis. We sought to identify risk factors and variables associated with outcomes in neonates with CDH who are SGA in comparison to neonates who are appropriate for gestational age (AGA).

METHODS

We used the multicenter Diaphragmatic Hernia Research & Exploration Advancing Molecular Science (DHREAMS) study to include neonates enrolled from 2005 to 2019. Chi-squared or Fisher's exact tests were used to compare categorical variables and t tests or Wilcoxon rank sum for continuous variables. Cox model analyzed time to event outcomes and logistic regression analyzed binary outcomes.

RESULTS

589 neonates were examined. Ninety were SGA (15.3%). SGA patients were more likely to be female (p = 0.003), have a left sided CDH (p = 0.05), have additional congenital anomalies and be diagnosed with a genetic syndrome (p < 0.001). On initial single-variable analysis, SGA correlated with higher frequency of death prior to discharge (p < 0.001) and supplemental oxygen requirement at 28 days (p = 0.005). Twice as many SGA patients died before repair (12.2% vs 6.4%, p = 0.04). Using unadjusted Cox model, the risk of death prior to discharge among SGA patients was 1.57 times the risk for AGA patients (p = 0.029). There was no correlation between SGA and need for ECMO, pulmonary hypertensive medication at discharge or oxygen at discharge. After adjusting for confounding variables, SGA no longer correlated with mortality prior to discharge or incidence of unrepaired defects but remained significant for oxygen requirement at 28 days (p = 0.03).

CONCLUSION

Infants with CDH who are SGA have worse survival and poorer lung function than AGA infants. However, the outcome of SGA neonates is impacted by other factors including gestational age, genetic syndromes, and particularly congenital anomalies that contribute heavily to their poorer prognosis.

Tunable rare-earth metal-organic frameworks for ultra-high selenite capture

Linkers and clusters with various conformations present challenges for the design and prediction of highly porous and stable rare-earth metal-organic frameworks (RE-MOFs) for trapping toxic ions in aqueous solutions. Herein, we designed and synthesized a series of RE-MOFs based on a malleable ligand to explore the effects of ligands, clusters, and configurations on structural stability. The results showed that the nonanuclear high-connected UPC-183 exhibited better stability than the hexanuclear low-connected RE-MOF (UPC-181/182 series). Due to the syngenetic effect of chemi- and physisorption, the adsorption capacity of UPC-183-Eu for selenite (SeO₃^2-) is as high as 308.39 mg/g, recorded one of the highest ever reported for MOFs. Furthermore, we accurately analyzed the adsorption site of UPC-183-Eu for SeO₃^2- through single-crystal structure and theoretical simulation. The ultra-high selenite adsorption capacity and removal efficiency endow UPC-183-Eu an excellent porous adsorbent for removing pollutants.

[Analysis of 2 diagnostic criteria of echocardiography for coronary artery aneurysm in Kawasaki disease]

Objective: To analyze the difference between Z score and previous criteria in the diagnosis characteristics of coronary artery aneurysm (CAA) in Kawasaki disease, and to investigate the clinical distribution of Kawasaki disease CAA in the Z score group. Methods: This study retrospectively analyzed the clinical and echocardiographic data of 2 419 children with Kawasaki disease in Shenzhen Children's Hospital from January 2009 to December 2019. The traditional criteria and Z score criteria were used to diagnose CAA, and the differences of diagnostic efficiency between the 2 diagnostic methods were analyzed. The clinical distribution characteristics of CAA in children with Kawasaki disease were analyzed by grouping their sex, clinical classification (complete Kawasaki disease, incomplete Kawasaki disease) the sensitivity to intravenous immunoglobulin (IVIG) (IVIG-sensitive Kawasaki disease,IVIG-unresponsive Kawasaki disease). And the course of the disease (≤6 weeks, >6-8 weeks, >8 weeks to 6 months) etc. The χ² test or Kruskal-Wallis test was used for comparison between the groups, and the Kappa test was used for consistency evaluation. Results: Among the 2 419 children with Kawasaki disease, 1 558 were males and 861 were females. The age of onset was 1.8 (1.0, 3.2) years. The rate of CAA by Z score criteria was higher than that by traditional method (21.9% (529/2 419) vs. 13.9% (336/2 419), χ²=1 074.94, P<0.001). Compared to the traditional method, the Z score criteria found higher rate of CAA in male patients, patients with incomplete Kawasaki disease, and IVIG-unresponsive patients (25.2% (392/1 558) vs. 16.0% (249/1 558), (32.7% (166/507) vs. 19.5% (99/507), 30.5% (95/312) vs. 24.0% (75/312), χ²=694.05, 216.19, 184.37, all P<0.001). The Z score criteria was consistent with the traditional method in diagnosing CAA (κ=0.642,P<0.001). Moreover, in the Z score criteria, the rate of CAA in males (25.2%, 392/1 558) was higher than that in females (15.9%, 137/861), higher in incomplete Kawasaki cases (32.7%, 166/507) than that in complete Kawasaki case (19.0%, 363/1 912), and higher in IVIG-unresponsive cases (30.4%, 95/312) than that in IVIG-sensitive cases (20.6%, 434/2 107), with statistically significant differences (χ²=27.76, 44.38, 15.43, all P<0.001). Coronary Z score of course ≤ 6 weeks was greater than that of course between>6-8 weeks and >8 weeks to 6 months (1.3 (0.7, 2.3) vs. 0.7 (0.3, 1.4), 0.7 (0.3, 1.3), Z=20.65, 13.70, both P<0.001). Conclusions: The rate of CAA in Kawasaki disease by Z score criteria is higher than that by traditional method. In the Z score group, most CAA occur within 6 weeks of the course of the disease, and the rate of CAA in male, incomplete Kawasaki disease, and IVIG-unresponsive is higher.

Flexible metal-organic frameworks for gas storage and separation

Flexible metal-organic frameworks (MOFs) have gradually attracted much attention due to their reversible structural changes and flexible structural responses. The basic research of flexible MOFs is to study their dynamic responses under different external stimuli and translate the responses into applications. Most research studies on flexible MOFs focus on gas storage and separation, but lack a systematic summary. Here, we review the development of flexible MOFs, the structural transformation under the external effects of temperature, pressure, and guest molecules, and their applications in gas storage and separation. Microporous MOFs with flexible structures provide unique opportunities for fine-tuning their performance because the pore shape and size can be controlled by external stimuli. The characteristics of breathing phenomena and large specific surface area make flexible MOFs suitable candidates for gas storage and separation. Finally, the application prospects of flexible MOFs are reported.

A turn-on NIR fluorescence sensor for gossypol based on Yb-based metal-organic framework

The development of analytical method for selective and sensitive detection of gossypol (Gsp), an extraction from the cotton plants, is important but still challenging in food safety and medical field. Herein, we reported a turn-on near infrared (NIR) fluorescence detection strategy for Gsp based on a metal-organic framework (MOF), QBA-Yb, which was prepared from 4,4'-(quinolone-5, 8-diyl) benzoate with Yb(NO₃)₃·5H₂O by solvothermal synthesis. The Gsp acted as another "antenna" to sensitize the luminescence of Yb³⁺, leading to the turn-on NIR emission upon 467 nm excitation. As Gsp concentration increased, the NIR emission at 973 nm enhanced gradually, thus enabling highly sensitive Gsp detection in a turn-on way. The experiment and theoretical calculation results revealed the presence of strong hydrogen bonds between Gsp molecules and the MOF skeleton. The developed QBA-Yb probe showed excellent characteristics for detection of Gsp molecules, accompanied by wide linear range (5-160 μg/mL), low detection limit (0.65 μg/mL) and short response time (within 10 min). We have further demonstrated that the QBA-Yb probe was successfully applied for the determination of Gsp in real samples of cottonseeds.

Metal-Organic Framework Based Gas Sensors

The ever-increasing concerns over indoor/outdoor air quality, industrial gas leakage, food freshness, and medical diagnosis require miniaturized gas sensors with excellent sensitivity, selectivity, stability, low power consumption, cost-effectiveness, and long lifetime. Metal-organic frameworks (MOFs), featuring structural diversity, large specific surface area, controllable pore size/geometry, and host-guest interactions, hold great promises for fabricating various MOF-based devices for diverse applications including gas sensing. Tremendous progress has been made in the past decade on the fabrication of MOF-based sensors with elevated sensitivity and selectivity toward various analytes due to their preconcentrating and molecule-sieving effects. Although several reviews have recently summarized different aspects of this field, a comprehensive review focusing on MOF-based gas sensors is absent. In this review, the latest advance of MOF-based gas sensors relying on different transduction mechanisms, for example, chemiresistive, capacitive/impedimetric, field-effect transistor or Kelvin probe-based, mass-sensitive, and optical ones are comprehensively summarized. The latest progress for making large-area MOF films essential to the mass-production of relevant gas sensors is also included. The structural and compositional features of MOFs are intentionally correlated with the sensing performance. Challenges and opportunities for the further development and practical applications of MOF-based gas sensors are also given.

Fabrication of mixed matrix membranes with regulated MOF fillers via incorporating guest molecules for optimizing light hydrocarbon separation performance

Guest molecules were incorporated into MOF fillers to construct MMMs with PIM-1 for enhanced gas separation performance.

The Distance From the Primary Intimal Tear to the Left Subclavian Artery Predicts Thoracic Aortic Enlargement After Thoracic Endovascular Aortic Repair of Type B Aortic Dissection: A Retrospective Cohort Study

PURPOSE

The purpose of this study was to evaluate the association between the distance from the primary intimal tear (PIT) to the left subclavian artery (LSA) (PIT-LSA distance) and the risk of aortic enlargement after thoracic endovascular aortic repair (TEVAR).

METHODS

This is a retrospective cohort study. A total of 228 patients were reviewed from the database of the Registry Of type B aortic dissection with the Utility of STent graft (ROBUST) study performed from January 1, 2011, to December 31, 2016. Of them, 196 patients were eligible for analysis. The PIT-LSA distance was defined as the length from the distal edge of the LSA orifice to the proximal edge of the PIT along the centerline of the true lumen. According to the border between zone 3 and zone 4 of the Ishimaru classification, patients were divided into group A (n = 117, PIT-LSA distance ≤ 2 cm) and group B (n = 79, PIT-LSA distance > 2 cm). Thoracic aortic enlargement (TAE) was defined as a thoracic aortic volume increase of ≥20%. Multivariate Cox regression was used to estimate the association between the PIT-LSA distance and risk of TAE after TEVAR.

RESULTS

The mean age was 52.3 ± 11.6 years, and 88.8% of patients were male. There were no significant differences between groups in demographic and baseline characteristics. The PIT-LSA distance was 1.1 cm (range, -1.6 to 2.0 cm) in group A, and 2.9 cm (range, 2.1-12.6 cm) in group B. TAE occurred in 27 patients in group A, and 6 in group B. The mean follow-up was 12.4 months (range, 0.10-83.1 months) in group A, and 12.63 months (range, 0.10-82.77 months) in group B. The cumulative 12- and 24-month rates of freedom from TAE were 79.0% and 71.3% in group A, versus 92.5% and 92.5% in group B, respectively. Multivariate Cox regression analysis revealed that the PIT-LSA distance was an independent predictor of TAE after TEVAR (adjusted hazard ratio, 0.66; 95% confidence interval, 0.48-0.90; p = 0.009).

CONCLUSION

Patients with a more proximal PIT location have a higher incidence of thoracic aortic enlargement after TEVAR. The location of the PIT in relation to the LSA can be used to identify patients who need closed surveillance after TEVAR or early preemptive intervention.

Multivariate Polycrystalline Metal-Organic Framework Membranes for CO2/CH4 Separation

Membrane technology is attractive for natural gas separation (removing CO₂, H₂O, and hydrocarbons from CH₄) because of membranes' low energy consumption and small environmental footprint. Compared to polymeric membranes, microporous inorganic membranes such as silicoaluminophosphate-34 (SAPO-34) membrane can retain their separation performance under conditions close to industrial requirements. However, moisture and hydrocarbons in natural gas can be strongly adsorbed in the pores of those membranes, thereby reducing the membrane separation performance. Herein, we report the fabrication of a polycrystalline MIL-160 membrane on an Al₂O₃ substrate by in situ hydrothermal synthesis. The MIL-160 membrane with a thickness of ca. 3 μm shows a remarkable molecular sieving effect in gas separation. Besides, the pore size and environment of the MIL-160 membrane can be precisely controlled using reticular chemistry by regulating the size and functionality of the ligand. Interestingly, the more polar fluorine-functionalized multivariate MIL-160/CAU-10-F membrane exhibits a 10.7% increase in selectivity for CO₂/CH₄ separation and a 31.2% increase in CO₂ permeance compared to those of the MIL-160 membrane. In addition, hydrophobic MIL-160 membranes and MIL-160/CAU-10-F membranes are more resistant to water vapor and hydrocarbons than the hydrophilic SAPO-34 membranes.

[Experimental study on the effect of three-dimensional porous structures on the vascularization rate of artificial dermis]

Objective: To explore the effects of orienting three-dimensional porous network (type A) and honeycomb briquette-shaped vertically penetrating three-dimensional porous network (type B) on the vascularization rate of artificial dermis. Methods: The experimental research method was used. The artificial dermis was composed of a double layer of silicone layer and scaffold layer. Based on the difference of scaffold layer, they were divided into type A and type B artificial dermis (type A dermis and type B dermis, for short) containing type A and type B structure, respectively. The type A and type B structures were prepared by gradient freeze-drying technique and physical pore-making technique, respectively. The micro-morphology of two kinds of dermis scaffold was observed by scanning electron microscopy. The porosity of two kinds of dermis scaffold was measured by the Pyrex method. According to the method of national medical industry standard, the hydroxyproline content in degradation liquids and their residues in two kind of dermis were determined after degradation at 4, 8, 13, and 24 h, reflecting the degradation rates of two kinds of dermis. According to the random number table, L929 cells were divided into type A dermis group, type B dermis group, negative control group, and positive control group. The positive control group was added with minimum essential medium (MEM) containing 5% dimethyl sulfoxide, The negative control group was added with high-density polyethylene extract, and the other two groups were added with the corresponding extract. At 24 hours after culture, the growth rate of L929 cells was detected by methyl thiazolyl tetrazolium, and the cytotoxicity was graded. L929 cells and human umbilical vein endothelial cells (HUVECs) were inoculated into pore plates with two kinds of dermis preinstalled. On 1, 4, 7, and 14 d after inoculating, the adhesion and growth of L929 cells on the surfaces of the two kinds of scaffolds were detected by immunofluorescence method. On 7 d after inoculating, the migration of the above two kinds of cells into the two kinds of dermal scaffolds was detected by immunofluorescence and hematoxylin-eosin (HE) staining. Three full-thickness skin defect wounds of 5.0 cm×5.0 cm were created on both sides of the back of three 6-month-old healthy male Ba-Ma mini pigs. According to the random number table, six columns of wounds were divided into type A dermis two-step method group, type B dermis two-step method group, and type B dermis one-step method group. The wounds in type A dermis two-step method group and type B dermis two-step method group were transplanted with type A or type B dermis respectively before, and with autologous split-thickness skin grafting later. The wounds in type B dermis one-step method group were transplanted in a synchronous procedure including type B dermis (without silicone layer) and autologous skin grafting simultaneously. The bleeding, exudation, and infection of the wounds on the back in type A dermis two-step method group and type B dermis two-step method group on the 7th day after the second transplantation and in type B dermis one-step method group on the 14th day after the first transplantation were generally observed. The area of autologous skin graft was measured by the transparent film grid method, and the survival rate of autologous skin was calculated. On 4, 7, and 14 d after the first transplantation, the inflammatory cells, fibroblasts (Fbs), and capillary infiltration into the scaffolds of the three groups were detected by HE staining. On 7, 14 d after the first transplantation, the vascularization of the scaffolds was further observed by immunohistochemistry. On 28, 90 d after the first operation, the degradation of the scaffolds of type A dermis and type B dermis was observed by HE staining. Data were statistically analyzed with one-way analysis of variance, independent sample t test, and Bonferroni correction. Results: A large number of round and oval micropores were evenly distributed on the surface of type A scaffold, and the cylindrical hole walls could be observed arranging in a parallel direction in the longitudinal section. The honeycomb briquette-shaped penetrating macropores on the surface of type B scaffold were arranged in an orderly matrix. The pore walls of the honeycomb briquette-shaped penetrating macropores were connected by micropores to form a network structure. The porosity of type A dermis was (93.21±0.72)%, which was similar to (95.88±1.00)% of type B dermis (t=4.653, P>0.05). The degradation rates of type A dermis at 4, 8, 13, and 24 h were similar to those of type B dermis at the corresponding time point (t=0.232, 0.856, 0.258, 7.716, P>0.05). At 24 h after culture, the proliferation rates of L929 cells in the type A dermis group, type B dermis group, and negative control group were significantly higher than those of the positive control group (t=2 393.46, 2 538.27, 1 077.77, P<0.01). The cytotoxicity rating of cells in positive control group was grade 4, while that of the other three groups was grade zero. On 1, 4, 7, and 14 d after inoculation, both L929 cells and HUVECs proliferated in a time-dependent manner in two kinds of dermal scaffolds. The adhesion growth and proliferation rate of the two kinds of cells on the surface of type B dermis was higher than that of type A dermis. On 7 d after inoculation, both L929 cells and HUVECs covered the surface of type B dermis and migrated into one side of the silicone layer. However, the above two kinds of cells migrated slowly into type A dermis, and only a few cells were found on one side of the silicone layer. There was no bleeding, exudation, or infection in the wounds repaired by type A and type B dermis. The survival rate of autologous skin grafting of 6 wounds in each group was 100%. On 4, 7, and 14 d after the first operation, inflammatory cells, Fbs, and capillaries gradually infiltrated into the scaffold layer, and the cell infiltration rate from high to low was type B dermis one-step method group, type B dermis two-step method group, and type A dermis two-step method group. The scaffold in wound in the type B dermis one-step method group gradually collapsed on 28 d after the first operation, and completely degraded in 3 months after the first operation. The scaffold degradation rate of type A dermis two-step method group was similar to that mentioned above. Conclusions: The honeycomb briquette-shaped vertically penetrating three-dimensional porous network structure of type B scaffold can accelerate its vascularization process, which is beneficial to autogenous split-thickness skin in one-step procedure to repair full-thickness skin defects wound in Ba-Ma mini pigs. Compared with the "two-step method" of staged transplantation of type A scaffold and autologous split-thickness skin, and one-step transplantation has equal efficacy and can provide a better choice for wound treatment.

Probing Gluon Spin-Momentum Correlations in Transversely Polarized Protons through Midrapidity Isolated Direct Photons in p^{↑}+p Collisions at sqrt[s]=200 GeV

Studying spin-momentum correlations in hadronic collisions offers a glimpse into a three-dimensional picture of proton structure. The transverse single-spin asymmetry for midrapidity isolated direct photons in p^{↑}+p collisions at sqrt[s]=200  GeV is measured with the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC). Because direct photons in particular are produced from the hard scattering and do not interact via the strong force, this measurement is a clean probe of initial-state spin-momentum correlations inside the proton and is in particular sensitive to gluon interference effects within the proton. This is the first time direct photons have been used as a probe of spin-momentum correlations at RHIC. The uncertainties on the results are a 50-fold improvement with respect to those of the one prior measurement for the same observable, from the Fermilab E704 experiment. These results constrain gluon spin-momentum correlations in transversely polarized protons.