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Secondary cell wall (SCW) thickening has a significant effect on the growth and development of plants, as well as in the resistance to various biotic and abiotic stresses. Lignin accounts for the strength of SCW. It is synthesized through the phenylpropanoid pathway that also leads to flavonoid synthesis. The coupling strategies for lignin and flavonoid syntheses are diverse in plants. How their syntheses are balanced by transcriptional regulation in fleshy fruits is still unclear. The diploid strawberry (Fragaria vesca) is a model for fleshy fruits research due to its small genome and wide scope of genetic transformation. SCW thickening is regulated by a multilevel transcriptional regulatory network wherein vascular-related NAC domains (VNDs) act as key regulators. In this study, we systematically characterized VNDs in Fragaria vesca and explored their functions. The overexpression of FvVND4c in diploid strawberry fruits resulted in SCW thickening and fruit color changes accompanied with the accumulation of lignin and flavonoids. Genes related to these phenotypes were also induced upon FvVND4c overexpression. Among the induced genes, we found FvMYB46 to be a direct downstream regulator of FvVND4c. The overexpression of FvMYB46 resulted in similar phenotypes as FvVND4c, except for the color change. Transcriptomic analyses suggest that both FvVND4c and FvMYB46 act on phenylpropanoid and flavonoid biosynthesis pathways, and induce lignin synthesis for SCW. These results suggest that FvVND4c and FvMYB46 cooperatively regulate SCW thickening and flavonoid accumulation in Fragaria vesca.

Secondary cell wall thickening plays a crucial role in plant growth and development. Diploid woodland strawberry (Fragaria vesca) is an excellent model for studying fruit development, but its molecular control of secondary wall thickening is largely unknown. Previous studies have shown that Arabidopsis NAC secondary wall thickening promoting factor1 (AtNST1) and related proteins are master regulators of xylem fiber cell differentiation in multiple plant species. In this study, a NST1-like gene, FvNST1b, was isolated and characterized from strawberry. Sequence alignment and phylogenetic analysis showed that the FvNST1b protein contains a highly conserved NAC domain, and it belongs to the same family as AtNST1. Overexpression of FvNST1b in wild-type Arabidopsis caused extreme dwarfism, induced ectopic thickening of secondary walls in various tissues, and upregulated the expression of genes related to secondary cell wall synthesis. In addition, transient overexpression of FvNST1b in wild-type Fragaria vesca fruit produced cells resembling tracheary elements. These results suggest that FvNST1b positively regulates secondary cell wall formation as orthologous genes from other species.

Background Corona Virus Disease 2019 (COVID-19) is a recently emerged life-threatening disease caused by SARS-CoV-2. It has the characteristics of rapid transmission, difficult treatment, rapid deterioration, and high mortality rate. Reliable and rapid diagnosis of SARS-CoV-2 infection is critical to treat patients and control transmission in time. Methods To detect SARS-CoV-2 nucleic acid faster and more convenient, RT-LAMP method (reverse transcription loop-mediated isothermal amplification) was developed. ORF1ab gene, E gene and N gene were selected as the target genes, because ORF1ab gene is the most specific and N gene is the most sensitive, while E gene has both sensitivity and specificity. Over thirty primer sets for them were designed, then the primer sets with rapid response and high specificity were screened out and their loop primers were designed and selected in order to improve the reaction speed further. Using these primers, RNA reverse transcription and nucleic acid amplification were performed in one step at 63 ℃ isothermal conditions, and the results can be judged by naked eyes through color change within 30 minutes. Finally, the optimal primer set for each gene was verified with over 208 clinical samples. Results ORF1ab gene, E gene and N gene were detected simultaneously by this method. ORF1ab gene has high specificity and the same sensitivity as RT-PCR currently used in clinic. Although N gene is less specific than ORF1ab, it is 80 times more sensitive than ORF1ab. The sensitivity and specificity of E gene are between them. Simultaneous detection of these three genes can neither cause false positives nor miss samples with low virus concentration, ensuring the sensitivity and specificity of SARS-CoV-2 detection. BLAST comparing results showed the primers for the three genes were highly specific for SARS-CoV-2. And the sequencing results of RT-LAMP products showed that the amplified fragments were unique to SARS-CoV-2. The accuracy of RT-LAMP assay was 99% as detecting 208 clinical specimens. Conclusions The RT-LAMP assay reported here has the advantages of rapid amplification, simple operation, and easy detection, which is useful for the rapid and reliable clinical diagnosis of SARS-CoV-2.

BACKGROUND:Fecal microbiota transplantation is an effective treatment for many gastrointestinal diseases, such as Clostridium difficile infection and inflammatory bowel disease, especially ulcerative colitis. Changes in colonic microflora may play an important role in the pathogenesis of ulcerative colitis, and improvements in the intestinal microflora may relieve the disease. Fecal bacterial transplants and oral probiotics are becoming important ways to relieve active ulcerative colitis. PURPOSE:This systematic review with meta-analysis compared the efficacy and safety of basic treatment combined with fecal microbiota transplantation or mixed probiotics therapy in relieving mild to moderate ulcerative colitis. METHODS:The PubMed, Embase, and Cochrane libraries (updated September 2019) were searched to identify randomized, placebo-controlled, or head-to-head trials assessing fecal microbiota transplantation or probiotic VSL#3 as induction therapy in active ulcerative colitis. We analyze data using the R program to obtain evidence of direct comparison and to generate intermediate variables for indirect treatment comparisons. RESULTS:Seven randomized, double-blind, placebo-controlled trials were used as the sources of the induction data. All treatments were superior to placebo. In terms of clinical remission and clinical response to active ulcerative colitis, direct comparisons showed fecal microbiota transplantation (OR = 3.47, 95% CI = 1.93-6.25) (OR = 2.48, 95% CI = 1.18-5.21) and mixed probiotics VSL#3 (OR = 2.40, 95% CI = 1.49-3.88) (OR = 3.09, 95% CI = 1.53-6.25) to have better effects than the placebo. Indirect comparison showed fecal microbiota transplantation and probiotic VSL#3 did not reach statistical significance either in clinical remission (RR = 1.20, 95% CI = 0.70-2.06) or clinical response (RR = 0.95, 95% CI = 0.62-1.45). In terms of safety, fecal microbiota transplantation (OR = 1.15, 95% CI = 0.51-2.61) and VSL #3 (OR = 0.90, 95% CI = 0.33-2.49) showed no statistically significant increase in adverse events compared with the control group. In terms of serious adverse events, there was no statistical difference between the fecal microbiota transplantation group and the control group (OR = 1.29, 95% CI = 0.46-3.57). The probiotics VSL#3 seems more safer than fecal microbiota transplantation, because serious adverse events were not reported in the VSL#3 articles. CONCLUSIONS:Fecal microbiota transplantation or mixed probiotics VSL#3 achieved good results in clinical remission and clinical response in active ulcerative colitis, and there was no increased risk of adverse reactions. There was no statistical difference between the therapeutic effect of fecal microbiota transplantation and that of mixed probiotics VSL#3. However, the use of fecal microbiota transplantation and probiotics still has many unresolved problems in clinical applications, and more randomized controlled trials are required to confirm its efficacy.

A series of star block polymers with a hyperbranched core and 26 arms are successfully synthesized by atom transfer radical polymerization of styrene (St), and poly(ethylene glycol) methyl ether methacrylate from a hyperbranched polystyrene (HBPS) multifunctional initiator. All-solid polymer electrolytes composed of these multiarm star polymers and lithium salts are prepared. The influences of polyoxyethylene (PEO) side-chain length, PEO content, lithium salt concentration and type, and the structure of polymer on ionic conductivity are systematically investigated. The resulting polymer electrolyte with the longest PEO side chains exhibits the best ionic conductive properties. The maximum conductivity is 0.8 × 10−4 S cm−1 at 25°C with EO/Li = 30. All the prepared multiarm star block polymers possess good thermal stability. The mechanical property is greatly improved owing to the existence of polystyrene blocks in the multiarm star polymer molecules, and flexible films can be obtained by solution-casting technique. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

The effects of different mixed external donors on the crystallization behavior and sequence length distribution of polypropylene prepared by MgCl2-supported TiCl4 Ziegler–Natta catalyst were studied through successive self-nucleation and annealing (SSA) technique. The SSA results show that the crystallization ability and the relative contents of long isotactic sequence length gradually increase with the increase of the relative component of Donor-1 (cyclohexylmethyldimethoxysilane, dicyclohexyl(dimethoxy)silane, and dipiperidinedimethoxysilane) in the different mixed external donors when the ratio of the mixed external donors/Ti (Si/Ti) is unchanged. The thickness distribution of lamellar also becomes broader, indicating the sequence length distribution of polypropylene gets broader. The crystallization ability and the relative contents of long isotactic sequence length of polypropylene prepared by the mixed cyclohexylmethyldimethoxysilane and n-propyltriethoxysilane (CN) external donors are lowest. However, the effect of the mixed dicyclohexyl(dimethoxy)silane and n-propyltriethoxysilane (HN) and the mixed dipiperidinedimethoxysilane and n-propyltriethoxysilane (PyN) external donors on the crystallization ability and sequence length of polypropylene are more significantly. Especially, the relative content of long isotactic sequence length increases sharply from 0.2 to 27.5% in the polypropylene chain of sample prepared by the mixed PyN external donors when the proportion of Donor 1 is running up to 90%. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

In this study, nanofiber cellulose (NFC) based on a 2,2,6,6-tetramethylpiperidine-1-oxyl radical oxidization method was successfully combined with chain-end-functionalized polyethylene containing alkoxysilane via silanization. Fourier transform infrared spectroscopy, transmission electron microscopy, contact angle measurements, Molau tests, and X-ray photoelectron spectroscopy analyses provided further evidence for the effectiveness of the surface modifications. The hydrophilic surface characteristics of NFC were changed to apparently hydrophobic for the modified nanofiber cellulose (M-NFC). Then, the linear low-density polyethylene (LLDPE)/M-NFC nanocomposite was prepared, and the mechanical properties, thermal properties, and crystallization properties of the LLDPE–M-NFC were investigated by tensile testing, thermogravimetric analysis, differential scanning calorimetry, and dynamic mechanical analysis. The results show that after modification, the thermal stability of NFC was enhanced. The interface between M-NFC and the matrix was good. The tensile strength and Young's modulus values of the nanocomposites were enhanced compared with those of LLDPE; in particular, the tensile strength and Young's modulus of the blend with 5 wt % M-NFC increased by 56 and 106%, respectively. The storage modulus of the nanocomposites was enhanced obviously over a wide temperature range. The addition of a small amount of M-NFC had slight effects on the crystallinity and melting temperature of LLDPE. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45387.

Four new diester compounds were prepared and used as internal donors (ID) to prepare MgCl2 supported titanium catalysts. Different diesters had notable influences on the porosity and the specific surface areas of the catalysts. The propylene polymerizations results showed that isopropyl groups(ID-2), cyclopentyl(ID-4) were more suitable substituents for diester compounds to replace phenyl(DIBP). The effects of different external donor (ED), Si/Ti ratio and hydrogen response on new ID precatalysts were evaluated by propylene polymerization.

The effect of successive self-nucleation and annealing (SSA) parameters including the annealing time ts, annealing temperature interval and heating and cooling rates on the crystallization properties of polypropylene were researched in detail. Based on those results, the crystallization behavior and the sequence length distribution of polypropylene with different isotacticity and propylene/1-butene copolymer with different 1-butene comonomer content prepared by Ziegler–Natta catalyst were studied through SSA. With the increase of the isotacticity of polypropylene, the sequence length of the polypropylene gradually increases. The polypropylene prepared by propylene bulk polymerization has stronger crystallization ability and longer sequence length than that prepared by propylene sully polymerization. For the propylene/1-butene copolymer, the crystallization ability gradually reduces and the sequence length of each chain segment gradually decreases with the increase of 1-butene content in copolymer. In addition, the polypropylene samples with similar isotactic index prepared by Ziegler–Natta catalyst and metallocene catalyst under similar polymerization condition were also characterized through the SSA technique. The results show that the sequence length of polypropylene prepared by Ziegler–Natta catalyst is far longer than that prepared by metallocene catalyst. The interesting phenomenon that polypropylene prepared by metallocene catalyst has multiple melting peaks after SSA treatment, which is similar to the polypropylene prepared by Ziegler–Natta catalyst, was first reported.