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Enhancing the flame retardancy with minimal impact on the mechanical and thermal performances of polymers remains a challenge. This study synthesized a phosphorus/nitrogen‐containing silane compound (D) using polyformaldehyde, KH‐550, and 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) as raw materials through the Kabachnik‐Fields reaction. After that, D was grafted onto the surface of graphene after hydrothermal treatment to obtain a nano hybrid flame retardant (D‐GR). And D‐GR/EP composites exhibited good flame resistance (LOI = 30.1% and UL‐94 reaches the V‐1 rating) even if the load on D‐GR was 1 wt%. Indeed, the total heat release, the peak heat release rate (PHRR), and the total smoke release of 1% D‐GR/EP dropped by 13.54%, 28.62%, and 44.32%, respectively, in comparison to pure EP. The mechanical performance of 1% D‐GR/EP was effectively maintained, as indicated by the results of impact, tensile and flexural tests. A systematic evaluation indicated that the accession of D‐GR effectively inhibited smoke and heat releases that are ascribed to the synergistic effect of phosphorus/nitrogen‐containing silane compound and graphene. In this study, a facile method was provided for the synthesis of halogen‐free flame‐retardant epoxy composites with superior performances. The combustion products of the as‐prepared composites complied with green and environmental protection standards. [ABSTRACT FROM AUTHOR]

A quadratic finite volume (FV) method for steady‐state Riesz space‐fractional diffusion equations (sFDEs) with variable diffusivity coefficient is developed using piecewise quadratic basis functions, and a resulting linear algebra system with two‐by‐two block‐type Toeplitz‐like coefficient matrix is formulated. It is proved that the method requires a minimum memory of order O(N), where N is the number of spatial partitions. Moreover, as two of the produced Toeplitz‐like submatrices are not square, a new fast nonsquare Toeplitz‐like matrix‐vector product is specially designed, which requires an almost linear computational complexity of order O(Nlog2N). Then, a fast version of biconjugate gradient stabilized (BiCGSTAB) solution algorithm, named FBiCGSTAB, is proposed for the FV scheme. The FV method combined with Crank‐Nicolson (CN) time discretization is applied to solve time‐dependent sFDEs, and an efficient CN‐FV scheme is developed and analyzed. Finally, numerical results are presented to show the utility of the fast FV and fast CN‐FV methods. [ABSTRACT FROM AUTHOR]

This study aimed to analyze the effect of carbon fiber nanotube tracheotomy (CFNT) under swallowing training (ST) combined with bronchofiberoscope alveolar lavage (BAL), so as to provide theoretical guidance for the clinical treatment of pulmonary infection. 40 patients with pulmonary infection were selected as the research objects, and the effects of ST combined with BAL were analyzed after CFNT. The patients were randomly divided into four groups: a control group (group A) and three observation groups (groups B, C, and D), with 10 cases in each group. Patients in group A received conventional treatment, patients in group B received conventional treatment + ST, patients in group C received conventional treatment + BAL, and patients in group D received conventional treatment + ST + BAL. The effect of ST + BAL was analyzed after CFNT. The results showed that compared with the group A, the number of lung infections and infection rates in groups C and D was reduced (P < 0.05); the use time and per capita cost of antibiotics in group A were much higher than those in the groups C and D (P < 0.05); and in group B and D, the number of successful extubation of tracheal catheters and the success rate were greatly increased (P < 0.05) and the average time of intubation was dramatically shortened (P < 0.05). The scores of the water swallow test (WST) in groups B and D were much lower than the score of group A (P < 0.05), and the scores for swallowing ability and swallowing dysfunction scores were much different from those of the group A (P < 0.05). In summary, after a CFNT, the lung infection and swallowing function of patients were effectively improved after ST + BAL.

It is widely believed that the quality and characteristics of Chinese strong-flavor liquor (CSFL) are closely related to the age of the pit mud; CSFL produced from older pit mud tastes better. This study aimed to investigate the alteration and interaction of prokaryotic communities across an age gradient in pit mud. Prokaryotic microbes in different-aged pit mud (1, 6, and 10 years old) were analyzed by Illumina MiSeq sequencing of the 16S rRNA gene. Analysis of the 16S rRNA gene indicated that the prokaryotic community was significantly altered with pit mud age. There was a significant increase in the genera Methanosarcina , Methanobacterium , and Aminobacterium with increased age of pit mud, while the genus Lactobacillus showed a significant decreasing trend. Network analysis demonstrated that both synergetic co-occurrence and niche competition were dominated by 68 prokaryotic genera. These genera formed 10 hubs of co-occurrence patterns, mainly under the phyla Firmicutes , Euryarchaeota , and Bacteroidetes , playing important roles on ecosystem stability of the pit mud. Environmental variables (pH, NH 4 + , available P, available K, and Ca 2+ ) correlated significantly with prokaryotic community assembly. The interaction of prokaryotic communities in the pit mud ecosystem and the relationship among prokaryotic communities and environmental factors contribute to the higher quality of the pit mud in older fermentation pits.