[Risk factors for bronchopulmonary dysplasia in twin preterm infants: a multicenter study]. / åŒèƒŽæ—©äº§å„¿æ”¯æ°”ç®¡è‚ºå‘è‚²ä¸è‰¯å±é™©å› ç´ åˆ†æžï¼šä¸€é¡¹å¤šä¸­å¿ƒç ”ç©¶.

OBJECTIVES: To investigate the risk factors for bronchopulmonary dysplasia (BPD) in twin preterm infants with a gestational age of <34 weeks, and to provide a basis for early identification of BPD in twin preterm infants in clinical practice. METHODS: A retrospective analysis was performed for the twin preterm infants with a gestational age of <34 weeks who were admitted to 22 hospitals nationwide from January 2018 to December 2020. According to their conditions, they were divided into group A (both twins had BPD), group B (only one twin had BPD), and group C (neither twin had BPD). The risk factors for BPD in twin preterm infants were analyzed. Further analysis was conducted on group B to investigate the postnatal risk factors for BPD within twins. RESULTS: A total of 904 pairs of twins with a gestational age of <34 weeks were included in this study. The multivariate logistic regression analysis showed that compared with group C, birth weight discordance of >25% between the twins was an independent risk factor for BPD in one of the twins (OR=3.370, 95%CI: 1.500-7.568, P<0.05), and high gestational age at birth was a protective factor against BPD (P<0.05). The conditional logistic regression analysis of group B showed that small-for-gestational-age (SGA) birth was an independent risk factor for BPD in individual twins (OR=5.017, 95%CI: 1.040-24.190, P<0.05). CONCLUSIONS: The development of BPD in twin preterm infants is associated with gestational age, birth weight discordance between the twins, and SGA birth.

Enhanced Photoinduced Carrier Separation in Fe-MOF-525/CdS for Photocatalytic Hydrogen Evolution: Improved Catalytic Dynamics with Specific Active Sites.

Single-atom metal-anchored porphyrin-based metal-organic frameworks (MOFs) have shown excellent light absorption, catalytic sites, and high stability during photocatalytic reactions, while there are still challenges for facile assembly with quantum dots to enhance catalytic dynamics. Herein, a kind of Fe single atom-doped MOF material (Fe-MOF-525) was ball milled with CdS in a proper ratio through Fe-N4 and Fe-N-C bonding, which showed the enhanced photoinduced carrier separation ability. As a result, extended light absorption ranges of CdS/Fe-MOF-5252.3 induced the promotion of the photocatalytic hydrogen (H2) value (3638.6 µmol g-1 h-1), which was 7.2 and 2.3 times higher than those of Fe-MOF-525 and CdS. In this work, the facile synthetic technique, specific active sites, and enhanced catalytic dynamics in the composite highlight the future research on MOF-based heterojunctions and their potential photocatalysis applications..

[Application of extracorporeal membrane oxygenation in the treatment of persistent pulmonary hypertension of the newborn]. / 体外膜肺氧合技术在持续肺动脉高压新生儿救治中的临床应用.

OBJECTIVES: To study the clinical value of extracorporeal membrane oxygenation (ECMO) in the treatment of persistent pulmonary hypertension of the newborn (PPHN). METHODS: A retrospective analysis was performed on the medical data of 11 neonates with PPHN who were treated with ECMO in the Neonatal Intensive Care Unit of Zhongshan People's Hospital from January 2015 to December 2021, involving the neonates' general information, clinical diagnosis, laboratory results, duration of ECMO treatment, complications during ECMO treatment, length of hospital stay, and outcome. RESULTS: Of the 11 neonates, 10 (91%) had successful weaning from ECMO, and 8 (73%) survived. For the 11 neonates, the mean duration of ECMO treatment was (81±50) hours (range: 26 to 185 hours), the mean duration of ventilator use was (198±105) hours (range: 57 to 392 hours), and the mean length of hospital stay was (22±15) days (range: 2 to 49 days). The oxygenation index and blood lactate level were significantly improved after 24 hours of ECMO treatment among the 11 neonates (P<0.05). Ten neonates had significantly reduced pulmonary artery pressure after 24 hours of ECMO treatment (P<0.05). One neonate had a progressive increase in the pulmonary artery pressure during EMCO treatment, succumbing to death. This neonate was diagnosed with alveolar capillary dysplasia based on the histopathological findings of the lung tissue and whole-exome sequencing results. Among the 11 children, 5 had intracranial hemorrhage, 1 had disseminated intravascular coagulation, 1 had gastric hemorrhage, 2 had pulmonary hemorrhage, 1 had renal insufficiency, and 3 had bleeding at the puncture site during ECMO treatment. CONCLUSIONS: ECMO is effective for the treatment of PPHN, however, the high incidence of complications of ECMO treatment suggests that it is important to carefully assess the indications and timing of ECMO treatment and improve the management of ECMO, which can improve the weaning rate and survival rate.

The association between frailty and severe disease among COVID-19 patients aged over 60 years in China: a prospective cohort study.

BACKGROUND: The coronavirus disease 2019 (COVID-19) has been a pandemic worldwide. Old age and underlying illnesses are associated with poor prognosis among COVID-19 patients. However, whether frailty, a common geriatric syndrome of reduced reserve to stressors, is associated with poor prognosis among older COVID-19 patients is unknown. The aim of our study is to investigate the association between frailty and severe disease among COVID-19 patients aged ≥ 60 years. METHODS: A prospective cohort study of 114 hospitalized older patients (≥ 60 years) with confirmed COVID-19 pneumonia was conducted between 7 February 2020 and 6 April 2020. Epidemiological, demographic, clinical, laboratory, and outcome data on admission were extracted from electronic medical records. All patients were assessed for frailty on admission using the FRAIL scale, in which five components are included: fatigue, resistance, ambulation, illnesses, and loss of weight. The outcome was the development of the severe disease within 60 days. We used the Cox proportional hazards models to identify the unadjusted and adjusted associations between frailty and severe illness. The significant variables in univariable analysis were included in the adjusted model. RESULTS: Of 114 patients, (median age, 67 years; interquartile range = 64-75 years; 57 [50%] men), 39 (34.2%), 39 (34.2%), and 36 (31.6%) were non-frail, pre-frail, and frail, respectively. During the 60 days of follow-up, 43 severe diseases occurred including eight deaths. Four of 39 (10.3%) non-frail patients, 15 of 39 (38.5%) pre-frail patients, and 24 of 36 (66.7%) frail patients progressed to severe disease. After adjustment of age, sex, body mass index, haemoglobin, white blood count, lymphocyte count, albumin, CD8+ count, D-dimer, and C-reactive protein, frailty (HR = 7.47, 95% CI 1.73-32.34, P = 0.007) and pre-frailty (HR = 5.01, 95% CI 1.16-21.61, P = 0.03) were associated with a higher hazard of severe disease than the non-frail. CONCLUSIONS: Frailty, assessed by the FRAIL scale, was associated with a higher risk of developing severe disease among older COVID-19 patients. Our findings suggested that the use of a clinician friendly assessment of frailty could help in early warning of older patients at high-risk with severe COVID-19 pneumonia.

Social support and clinical improvement in COVID-19 positive patients in China.

OBJECTIVES: To explore the relationship between psychosocial support related factors and the mental health of COVID-19 positive patients. METHODS: This exploratory study of 35 COVID-19 positive patients were enrolled between February 1 to March 1, 2020. Sleep quality, depression, anxiety, and social support were measured and social support related data of participants were collected. Psychological intervention was administered and patients were followed two weeks post intervention. Linear regression was performed to explore the relationship between psychosocial risk factors and improvement of psychological symptoms. FINDINGS: Thirty-two individuals exhibited sleep, depressive and anxiety symptoms which improved post support intervention. At baseline, symptoms were associated with gender, severity of pneumonia, social support. Better social support at follow-up and improvement from COVID-19 predicted improvement in their psychological symptoms. DISCUSSION: This initial evidence from China may stress the importance of administering psychosocial intervention during the treatment of COVID-19 for better patient outcomes in other countries.

[Application value of whole exome sequencing in critically ill neonates with inherited diseases].

OBJECTIVE: To study the application value of whole exome sequencing (WES) in critically ill neonates with inherited diseases. METHODS: A total of 66 critically ill neonates with suspected inherited diseases or unclear clinical diagnosis who were admitted to the neonatal intensive care unit were enrolled as subjects. The clinical data of the neonates were collected, and venous blood samples were collected from the neonates and their parents for WES. The clinical manifestations of the neonates were observed to search for related pathogenic gene mutations. RESULTS: Among the 66 critically ill neonates with suspected inherited diseases or unclear clinical diagnosis (34 boys and 32 girls), 14 (21%) were found to have gene mutations by WES. One neonate had no gene mutation detected by WES but was highly suspected of pigment incontinence based on clinical manifestations, and multiplex ligation-dependent probe amplification detected a heterozygous deletion mutation in exons 4-10 of the IKBKG gene. Among the 15 neonates with gene mutations, 10 (67%) had pathogenic gene mutation, 1 (7%) was suspected of pathogenic gene mutation, and 4 (27%) had gene mutations with unknown significance. Among the 15 neonates, 13 underwent chromosome examination, and only 1 neonate was found to have chromosome abnormality. CONCLUSIONS: Chromosome examination cannot be used as a diagnostic method for inherited diseases, and WES detection technology is an important tool to find inherited diseases in critically ill neonates with suspected inherited diseases or unclear clinical diagnosis; however WES technology has some limitation and it is thus necessary to combine with other sequencing methods to achieve an early diagnosis.

Regioselective deoxygenative chalcogenation of 7-azindole N-oxides promoted by I2/PEG-200.

We developed a general and sustainable approach for the regioselective deoxygenative chalcogenation of 7-azindole N-oxides; the combination of an internal oxidant and a green solvent has been used successfully for the synthesis of mono- and dichalcogenyl 7-azaindoles which are of pharmaceutical interest. The regioselectivity is tunable by the variation of the reaction conditions. I2/PEG was established as an efficient and reusable catalytic system for C-H chalcogenation. This developed methodology has great potential for practical utility, with a broad substrate scope, green reaction conditions, and operational simplicity.

[mRNA expression of MDR3 gene in the blood of preterm infants with parenteral nutrition-associated cholestasis].

OBJECTIVE: To study the association between the expression of the MDR3 gene and the pathogenesis of parenteral nutrition-associated cholestasis (PNAC) in preterm infants. METHODS: Among the preterm infants who were admitted to the hospital from June 2011 to November 2017 and received parenteral nutrition for more than 14 days, 80 who did not develop PNAC were enrolled as non-PNAC group, and 76 who developed PNAC were enrolled as PNAC group. On days 1, 14, 30, 60 and 90 after birth, serum hepatobiliary biochemical parameters [alanine aminotransferase (ALT), total bilirubin (TBil), direct bilirubin (DBil), total bile acid (TBA) and gamma-glutamyl transpeptidase (γ-GT)], fibrosis indices [hyaluronic acid, laminin, procollagen III N-terminal peptide and type IV collagen] and clinical manifestations were observed. Real-time quantitative PCR was used to measure the mRNA expression of MDR3 in both groups, and the correlation between the mRNA expression of MDR3 and serum hepatobiliary biochemical parameters was analyzed. RESULTS: In the PNAC group, serum levels of hepatobiliary biochemical parameters and fibrosis indices increased on day 14 after birth and reached the peak on day 30 after birth, followed by a reduction on day 60 after birth. On days 14, 30, 60 and 90 after birth, the PNAC group had significantly higher serum levels of hepatobiliary biochemical parameters and fibrosis indices than the non-PNAC group (P<0.05). The PNAC group had higher relative mRNA expression of MDR3 in peripheral blood cells than the non-PNAC group (P<0.05). In the PNAC group, the relative mRNA expression of MDR3 in peripheral blood cells was negatively correlated with serum levels of hepatobiliary biochemical parameters (ALT, TBil, DBil, TBA and γ-GT) (P<0.001). CONCLUSIONS: High mRNA expression of MDR3 in preterm infants may be associated with the development of PNAC, and further studies are needed to identify the mechanism.

Connexin 31.1 degradation requires the Clathrin-mediated autophagy in NSCLC cell H1299.

Connexins have relative short half-lives. Connexin 31.1 (Cx31.1) was newly reported to be down-regulated in non-small cell lung cancer cell lines, and displayed tumour-suppressive properties. However, no reports describing how a cell regulates Cx31.1 level were found. In this study, Cx31.1 was suggested to be degraded through both ubiquitin-proteasome system (UPS) and autophagy. Blockage of UPS with MG-132 increased Cx31.1 level, but could not inhibit the degradation of Cx31.1 completely. In H1299 cells stably expressing Cx31.1, Cx31.1 reduced when autophagy was induced through starvation or Brefeldin A treatment. Knockdown of autophagy-related protein ATG5 could increase the cellular level of Cx31.1 both under normal growth condition and starvation-induced autophagy. Colocalization of Cx31.1 and autophagy marker light chain 3 (LC3) was revealed by immunofluorescence analysis. Coimmunoprecipitation and immunofluorescence showed that Cx31.1 might interact with clathrin heavy chain which was newly reported to regulate autophagic lysosome reformation (ALR) and controls lysosome homoeostasis. When clathrin expression was knockdown by siRNA treatment, the level of Cx31.1 increased prominently both under normal growth condition and starvation-induced autophagy. Under starvation-induced autophagy, LC3-II levels were slightly accumulated with siCla. treatment compared to that of siNC, which could be ascribed to that clathrin knockdown impaired the late stage of autophagy, ALR. Taken together, we found autophagy contributed to Cx31.1 degradation, and clathrin might be involved in the autophagy of Cx31.1.

Effect of cyclooxygenase-2-specific inhibitors on postoperative analgesia after major open abdominal surgery.

The aim of this study was to examine the effect of cyclooxygenase-2 (COX-2)-specific medications on postoperative analgesia after major open abdominal surgery. This is was a prospective, randomized controlled, double-blind study conducted on 90 patients who underwent major open abdominal surgery between September 2011 and June 2012, in the General Surgery Department, Jinling Hospital. After written informed consent, patients were prospectively and randomly assigned to one of three treatment groups before surgery, and were scheduled to receive different analgesic drugs according to randomization. We assessed the patients' pain levels using pain intensity score and adverse events during our study period. The group that received intravenous parecoxib for 3 days, and continued oral celecoxib for 4 days had better postoperative analgesia than other groups. COX-2-specific inhibitors are safe and effective in reducing postoperative pain in patients who have undergone major open abdominal surgery. Additionally, sufficient postoperative analgesia, lasting for 1 week, was necessary for patients to obtain satisfactory pain control after major open abdominal surgery.

Prediction of the critical energy release rate for rat femoral cortical bone structure under different failure conditions.

BACKGROUND AND OBJECTIVE: Critical energy release rate is a global fracture parameter that could be measured during the failing process, and its value may change under different failure conditions even in the same bone structure. The aim of this study was to propose an approach that combined the experimental test and finite element analysis to predict the critical energy release rates in the femoral cortical bone structures under compression and three-point bending loads. METHODS: Three-point bending and compression experiments and the corresponding fracture simulations were performed on the rat femoral cortical bone structures. Different values of energy release rate were repeatedly assigned to the finite element models to perform fracture simulations, and then the load-displacement curves predicted in each simulation were compared with the experimental data to back-calculate the critical energy release rate. RESULTS: The predicted data were similar to the experimental results when the calibrated energy release rate was suitable. The results showed that the cortical bone structure occurred shear open failure under compression load, and the predicted critical energy release rate was 0.12 N/mm. The same cortical bone structure occurred tensile open failure under three-point bending load, and the predicted critical energy release rate was 0.16 N/mm. CONCLUSIONS: The critical energy release rates were different under various failure conditions in one cortical bone structure. A comprehensive analysis from the perspectives of material mechanical properties, failure mode, and damage fracture mechanism was conducted to reveal the reasons for the differences in the critical energy release rate in the cortical bone structure, which provided a theoretical basis for the measurement of the critical energy release rate and the accurate fracture simulation.

Esterification of Thioamides via Selective N-C(S) Cleavage under Mild Conditions.

Herein, we report an exceedingly mild method for the direct, transition-metal-free esterification of thioamides through the selective generation of tetrahedral intermediates. The method represents the first transition-metal-free approach to the thioamide to thionoester transformation in organic synthesis. This reactivity has been accomplished through N,N-Boc2-thioamides that engage in ground-state destabilization of the nN → π*C═S conjugation. The ground-state destabilization of "single-atom" bioisosteric thioamides will expand the arsenal of valuable amide bond functionalization reactions.

miRNA-633 and KAI1 as Potential Biomarkers of Malignant Melanoma with Gastric Cancer.

OBJECTIVE: Malignant melanoma with gastric cancer is one of the most malignant tumors. However, there have been no reports on the effects of KAI1 and miRNA-633 on the survival and prognosis of patients with malignant melanoma with gastric cancer. METHODS: Fifty patients with malignant melanoma and gastric cancer were collected from October 2017 to December 2019. The clinical parameters included clinical information, such as sex, age, tumor size, and tumor staging. RT-qPCR was used to detect the expression of KAI1 and miRNA- 633. The role of KAI1 and miRNA-633 on the overall survival of melanoma was explored by the Pearson chi-square test, Spearman-rho correlation test, Univariate and multivariate cox regression analyses, and Kaplan-Meier method. Furthermore, the bioinformatic analysis was used to verify the role of KAI1 and miRNA-633 on malignant melanoma with gastric cancer. RESULTS: The expression of KAI1 and miRNA-633 was significantly related with the tumor size and staging of tumor (p<0.05) based on the Pearson chi-square test. Spearman's correlation coefficient displayed that KAI1 was significantly correlated with the miRNA-633 (ρ=-0.439, p=0.001). The result of multivariate cox proportional regression analysis showed that KAI1 (HR =0.109, 95% CI: 0.031-0.375, p< 0.001), and miRNA-633 (HR = 13.315, 95% CI: 3.844-46.119, p<0.001) were significantly associated with overall survival. CONCLUSION: The low expression level of KAI1 and high expression of miRNA-633 are significantly correlated with the poor overall survival prognosis of malignant melanoma with gastric cancer, to provide a basis for KAI1 and miRNA-633 to become novel molecular targets for malignant melanoma with gastric cancer.

Mdr3 gene mutation in preterm infants with parenteral nutrition-associated cholestasis.

To investigate the relationship of multidrug resistance 3 (Mdr3) gene mutation and parenteral nutrition-associated cholestasis (PNAC) in preterm infants. Preterm infants who had received total parenteral nutrition for at least 14 days were enrolled: 76 preterm infants in the PNAC group and 80 preterm infants in the non-PNAC group. Genomic DNA was extracted from white blood cells. Twenty-eight exons of the Mdr3 gene were amplified by polymerase chain reaction. PNAC infants of 1 month corrected age with the Mdr3 gene mutation and abnormal liver biochemistry were selected for the experimental liver biopsy group. Five normal adult living liver transplantation donors were enrolled in a normal donor group. The Mdr3 missense mutations c.1031G>A, c.3347G>A, and c.485T>A, and the Mdr3 frameshift mutation c.2793_2794insA were found in the PNAC group. The allele frequency and genotype frequency of c.1031G>A, c.3347G>A, and c.485T>A in the Mdr3 gene in the PNAC group were significantly higher than those in non-PNAC group (p < 0.05). The rate of Mdr3 gene mutations c.1031G>A, c.485T>A, c.3347G>A, and c.2793_2794insA in the PNAC group was higher than in the non-PNAC group (21.05% vs. 1.25%, respectively, χ2  = 15.747, p < 0.05). Mdr3 gene mutations c.2793_2794insA, c.1031G>A, c.3347G>A, and c.485T>A may be the genetic cause of PNAC.

Analysis of the Application Value of X-Ray Digital Tomographic Fusion Technique in Urinary System Diseases.

OBJECTIVE: To explore the application value of the X-ray digital tomographic fusion technique in the diagnosis of urinary system diseases. METHODS: 500 patients with suspected urinary diseases in our hospital were examined by three methods: X-ray digital tomographic fusion imaging (DTS), intravenous pyelography (IVP), and abdominal plain film (KUB), and the image quality before and after tomographic fusion was objectively evaluated. The image quality could be divided into three grades: excellent, good, and poor. RESULTS: The image excellent rate of DTS (88%) was higher than that of IVP (27.5%). The sensitivity of DTS in the diagnosis of renal cyst and space occupying of the bladder was higher than that of IVP (P < 0.05). The accuracy rate of DTS in the diagnosis of urinary calculi was 93.33%, higher than 63.3% of KUB (P < 0.001). The accuracy rate of DTS in the diagnosis of ureteral stricture was 90%, higher than 65% of IVP (P=0.03). The accuracy of DTS in the diagnosis of hydronephrosis was higher than that of IVP and KUB (P < 0.05). CONCLUSION: In the examination of urinary system-related diseases, high-definition images can be obtained by timely using sectional fusion technology. Compared with conventional IVP, space occupying lesions such as the bladder and kidney can be displayed more clearly with the help of the tomographic fusion technique, which is helpful to improve the possibility of finding lesions and is of great significance in clinical application.

Role of PIM2 in acute lung injury induced by sepsis.

Pediatric sepsis can cause lung damage leading to death in children. In addition, its complicated pathogenesis currently presents a difficult problem in the medical field. Proviral integrations of Moloney virus 2 (PIM2) is a prognostic marker of pediatric sepsis; therefore, the aim of the present study was to investigate the role of PIM2 in lung injury caused by pediatric sepsis. To meet this aim, the expression of PIM2 in lipopolysaccharide (LPS)-induced BEAS-2B pulmonary epithelial cells was detected using reverse transcription-quantitative (RT-q)PCR and western blotting. Subsequently, the expression of PIM2 was inhibited using the cell transfection technique. Cell Counting Kit-8, TUNEL and western blotting, use of a fluorescence kit, ELISA detection kits were used to detect the expression of inflammatory- and cell injury-associated indicators following PIM2 inhibition. In addition, the expression of proteins known to be associated with the Toll-like receptor 2 (TLR2)/myeloid differentiation primary response 88 (MyD88) pathway were also assessed using western blotting. Finally, the simultaneous inhibition of PIM2 expression and overexpression of TLR2 were investigated in an attempt to elucidate the underlying mechanism. The expression level of PIM2 was revealed to be increased in LPS-induced BEAS-2B cells. Interference with PIM2 expression led to an increase in BEAS-2B cell viability, the inhibition of apoptosis and a reduction in oxidative stress and the inflammatory response. These processes were also revealed to be accomplished via downregulation of the TLR2/MyD88 signaling pathway. Overall, the present study demonstrated that knockdown of PIM2 alleviated LPS-induced bronchial epithelial cell injury by inhibiting the TLR2/MyD88 pathway.

Case report: Recombinant human epidermal growth factor gel plus kangfuxin solution in the treatment of aplasia cutis congenita in a case with Adams-Oliver syndrome.

Background: Aplasia cutis congenita is a congenital disorder with the absence of skin, muscle and(or) bone. It usually affects the scalp. The presence of a large scalp defect can be potentially serious when complicated with hemorrhage and infection. Early healing of this condition is beneficial to improve the prognosis of infants. Study case: A full-term newborn male was born with a round-shaped defect at the vertex of the scalp and skull (dimensions, 8 cm × 9 cm). The infant had a large deletion encompassing the 15.1 region of chromosome 15, including the DLL4 gene. Genetic testing was positive for Adams-Oliver syndrome (AOS). After two months of recombinant human epidermal growth factor gel combined with kangfuxin solution therapy, the skin defects of the scalp healed remarkably. The infant had regular follow-up appointments. At the age of 5 months, the defect became smaller, hairless, and showed good granulation tissue. At 2 years of age, the child's Gesell Developmental Schedules was 70. Conclusion: Recombinant human epidermal growth factor gel combined with kangfuxin solution was a successful conservative treatment for an infant with a large scalp defect accompanied by AOS.

A successful case of preimplantation genetic testing for monogenic disorder for aplasia cutis congenita.

Background: Aplasia cutis congenita (ACC), also called congenital cutaneous hypoplasia, is a serious disease in newborns. Children with ACC often die due to wound infections and bleeding. How the incidence of ACC can be reduced is a question that needs to be solved urgently. Case report: We reported a mother who had delivered two children with ACC, both of whom were diagnosed with ACC type VI, skin defects, limb deformities, and congenital heart malformations. One infant died a few days after birth, and another died in utero in the second trimester. Genetic testing in both children showed a heterozygous mutation in the ITGB4 gene [17q25 exon 8, c. 794 dupC, (p. Ala266fs) and exon 15, c. 1860G > A]. The mother later successfully gave birth to a healthy baby using Preimplantation Genetic Testing for Monogenic disorders(PGD-M). Conclusion: The PGD-M technique is highly valuable in reducing the incidence of ACC and improving the prognoses of newborns.

Ultrahigh Density of Atomic CoFe-Electron Synergy in Noncontinuous Carbon Matrix for Highly Efficient Magnetic Wave Adsorption.

Improving the atom utilization of metals and clarifying the M-M' interaction is both greatly significant in assembling high-performance ultra-light electromagnetic wave-absorbing materials. Herein, a high-temperature explosion strategy has been successfully applied to assemble the hierarchical porous carbon sponge with Co-Fe decoration via the pyrolysis of the energetic metal organic framework. The as-constructed hybrid displays a superior reflection loss (RL) value of - 57.7 dB and a specific RL value of - 192 dB mg-1 mm-1 at 12.08 GHz with a layer thickness of 2.0 mm (loading of 15 wt%). The off-axis electron hologram characterizes the highly distributed numerous polarized nanodomain variable capacitors, demonstrating the dipole and interfacial polarization along the edges of the nanopores. More importantly, the X-ray absorption spectroscopy analysis verifies the mutual interaction between the metal cluster and carbon matrix and the electronic coupling responsible for the greatly improved electromagnetic wave absorption.