Widespread utilization of polyethylene terephthalate (PET) has caused a variety of environmental and health problems; thus, the enzymatic degradation of PET can be a promising solution. Although ...PETase from Ideonalla sakaiensis (IsPETase) has been reported to have the highest PET degradation activity under mild conditions of all PET-degrading enzymes reported to date, its low thermal stability limits its ability for efficient and practical enzymatic degradation of PET. Using the structural information on IsPETase, we developed a rational protein engineering strategy using several IsPETase variants that were screened for high thermal stability to improve PET degradation activity. In particular, the IsPETaseS121E/D186H/R280A variant, which was designed to have a stabilized β6-β7 connecting loop and extended subsite IIc, had a T m value that was increased by 8.81 °C and PET degradation activity was enhanced by 14-fold at 40 °C in comparison with IsPETaseWT. The designed structural modifications were further verified through structure determination of the variants, and high thermal stability was further confirmed by a heat-inactivation experiment. The proposed strategy and developed variants represent an important advancement for achieving the complete biodegradation of PET under mild conditions.
Transposable elements are major evolutionary forces which can cause new genome structure and species diversification. The role of transposable elements in the expansion of nucleotide-binding and ...leucine-rich-repeat proteins (NLRs), the major disease-resistance gene families, has been unexplored in plants.
We report two high-quality de novo genomes (Capsicum baccatum and C. chinense) and an improved reference genome (C. annuum) for peppers. Dynamic genome rearrangements involving translocations among chromosomes 3, 5, and 9 were detected in comparison between C. baccatum and the two other peppers. The amplification of athila LTR-retrotransposons, members of the gypsy superfamily, led to genome expansion in C. baccatum. In-depth genome-wide comparison of genes and repeats unveiled that the copy numbers of NLRs were greatly increased by LTR-retrotransposon-mediated retroduplication. Moreover, retroduplicated NLRs are abundant across the angiosperms and, in most cases, are lineage-specific.
Our study reveals that retroduplication has played key roles for the massive emergence of NLR genes including functional disease-resistance genes in pepper plants.
If they could be easily exfoliated, layered materials would become a diverse source of two-dimensional crystals whose properties would be useful in applications ranging from electronics to energy ...storage. We show that layered compounds such as MoS₂, WS₂, MoSe₂, MoTe₂, TaSe₂, NbSe₂, NiTe₂, BN, and Bi₂Te₃ can be efficiently dispersed in common solvents and can be deposited as individual flakes or formed into films. Electron microscopy strongly suggests that the material is exfoliated into individual layers. By blending this material with suspensions of other nanomaterials or polymer solutions, we can prepare hybrid dispersions or composites, which can be cast into films. We show that WS₂ and MoS₂ effectively reinforce polymers, whereas WS₂/carbon nanotube hybrid films have high conductivity, leading to promising thermoelectric properties.
Semiconducting 2D MoS2 flakes produced by liquid phase exfoliation are contacted with metal electrodes, which are defined by electron beam lithography. Electrical analysis of the ...metal–semiconductor–metal structures reveals high mobilities for individual MoS2 flakes. Thus, scalable liquid‐phase exfoliation of layered semiconductor compounds can yield novel materials with potential uses in future electronic devices.
PurposeThis study examined how social media influencers create and leverage followers' attachment to deliver marketing messages by applying human brand theory and attachment ...theory.Design/methodology/approachAn online self-administered survey by 490 US adults who are Millennials (27–40) or Generation Z (18–26) in 2020 and currently following any specific social media influencer was conducted and analyzed.FindingsThe results suggest that homophily, social presence and attractiveness create a greater attachment. Attachment enhances followers' loyalty to the influencer and advertising credibility and reduces their resistance to advertising, whereas it does not affect advertising perception.Research limitations/implicationsThis study suggests the significance of emotional bonding which explains the recent industry shifts targeting “micro-influencers” and long-term partnerships. The attachment to the influencer leads the followers to become loyal, credit marketing messages and lower the resistance without altering the perception as advertising.Originality/valueThis study identifies how attachment affects the followers' perception and response to the marketing message delivered by the influencer while previous studies were limited to the formulation process of attachment.
Summary
Plants possess hundreds of intracellular immune receptors encoding nucleotide‐binding domain leucine‐rich repeat (NLR) proteins. Full‐length NLRs or a specific domain of NLRs often induce ...plant cell death in the absence of pathogen infection.
In this study we used genome‐wide transient expression analysis to identify a group of NLRs (ANLs; ancient and autonomous NLRs) carrying autoactive coiled‐coil (CCA) domains in pepper (Capsicum annuum). CCA‐mediated cell death mimics hypersensitive cell death triggered by the interaction between NLRs and pathogen effectors.
Sequence alignment and mutagenesis analyses revealed that the intact α1 helix of CCAs is critical for both CCA‐ and ANL‐mediated cell death. Cell death induced by CCAs does not require NRG1/ADR1 or NRC type helper NLRs, suggesting ANLs may function as singleton NLRs. We also found that CCAs localize to the plasma membrane, as demonstrated for Arabidopsis singleton NLR ZAR1. Extended studies revealed that autoactive CCAs are well conserved in other Solanaceae plants as well as in rice, a monocot plant. Further phylogenetic analyses revealed that ANLs are present in all tested seed plants (spermatophytes).
Our study not only uncovers the autonomous NLR clade in plants but also provides powerful resources for dissecting the underlying molecular mechanism of NLR‐mediated cell death in plants.
Background
Staphylococcus (S) aureus colonization is known to cause skin barrier disruption in atopic dermatitis (AD) patients. However, it has not been studied how S. aureus induces aberrant ...epidermal lipid composition and skin barrier dysfunction.
Methods
Skin tape strips (STS) and swabs were obtained from 24 children with AD (6.0 ± 4.4 years) and 16 healthy children (7.0 ± 4.5 years). Lipidomic analysis of STS samples was performed by mass spectrometry. Skin levels of methicillin‐sensitive and methicillin‐resistant S. aureus (MSSA and MRSA) were evaluated. The effects of MSSA and MRSA were evaluated in primary human keratinocytes (HEKs) and organotypic skin cultures.
Results
AD and organotypic skin colonized with MRSA significantly increased the proportion of lipid species with nonhydroxy fatty acid sphingosine ceramide with palmitic acid (N‐16:0 NS‐CER, sphingomyelins 16:0–18:0 SM), and lysophosphatidylcholines 16:0–18:0 LPC, but significantly reduced the proportion of corresponding very long‐chain fatty acids (VLCFAs) species (C22–28) compared to the skin without S. aureus colonization. Significantly increased transepidermal water loss (TEWL) was found in MRSA‐colonized AD skin. S. aureus indirectly through interleukin (IL)‐1β, tumor necrosis factor (TNF)‐α, IL‐6, and IL‐33 inhibited expression of fatty acid elongase enzymes (ELOVL3 and ELOVL4) in HEKs. ELOVL inhibition was more pronounced by MRSA and resulted in TEWL increase in organotypic skin.
Conclusion
Aberrant skin lipid profiles and barrier dysfunction are associated with S. aureus colonization in AD patients. These effects are attributed to the inhibition of ELOVLs by S. aureus‐induced IL‐1β, TNF‐α, IL‐6, and IL‐33 seen in keratinocyte models and are more prominent in MRSA than MSSA.
MRSA induces a broad range of cytokines, while MSSA induces IL‐1β and TNF‐α. Staphylococcus aureus‐induced IL‐1β, TNF‐α, and IL‐6 inhibit ELOVL3, resulting in accumulation of lipids with C14‐C18 FAs, while MRSA‐induced IL‐33 inhibits both ELOVL3 and ELOVL4, concomitantly increasing lipids with C14‐C18 FAs and decreasing lipids with FAs ≥ 22. S. aureus‐mediated aberrant lipid profiles cause increased TEWL and skin barrier dysfunction.Abbreviations: 3D skin, organotypic skin; ELOVL, fatty acid elongase; FA, fatty acid; IL, interleukin; MRSA, methicillin‐resistant Staphylococcus aureus; MSSA, methicillin‐sensitive Staphylococcus aureus; SA, Staphylococcus aureus; TEWL, transepidermal water loss; TNF, tissue necrosis factor
Telomerase has attracted much attention as a universal cancer biomarker because telomerase is overexpressed in more than 85% of human cancer cells while suppressed in normal somatic cells. Since a ...strong association exists between telomerase activity and human cancers, the development of effective telomerase activity assay is critically important. Here, a nanogap‐rich Au nanowire (NW) surface‐enhanced Raman scattering (SERS) sensor is reported for detection of telomerase activity in various cancer cells and tissues. The nanogap‐rich Au NWs are constructed by deposition of nanoparticles on single‐crystalline Au NWs and provided highly reproducible SERS spectra. The telomeric substrate (TS) primer‐attached nanogap‐rich Au NWs can detect telomerase activity through SERS measurement after the elongation of TS primers, folding into G‐quadruplex structures, and intercalation of methylene blue. This sensor enables us to detect telomerase activity from various cancer cell lines with a detection limit of 0.2 cancer cells mL−1. Importantly, the nanogap‐rich Au NW sensor can diagnose gastric and breast cancer tissues accurately. The nanogap‐rich Au NW sensors show strong SERS signals only in the presence of tumor tissues excised from 16 tumor‐bearing mice, while negligible signals in the presence of heated tumor tissues or normal tissues. It is anticipated that nanogap‐rich Au NW SERS sensors can be used for a universal cancer diagnosis and further biomedical applications including a diverse biomarker sensing.
A nanogap‐rich Au nanowire (NW) surface‐enhanced Raman scattering (SERS) sensor is developed for ultrasensitive and specific detection of telomerase activity. The optimized nanogap‐rich Au NW can provide highly reproducible and strong SERS signals. Using nanogap‐rich Au NW SERS sensors, telomerase activities of cancer cells and tumor tissues are successfully detected, suggesting the potential applicability of nanogap‐rich Au NW SERS sensor in cancer diagnosis.
Semisolid magnetization transfer contrast (MTC) and chemical exchange saturation transfer (CEST) MRI based on MT phenomenon have shown potential to evaluate brain development, neurological, ...psychiatric, and neurodegenerative diseases. However, a qualitative MT ratio (MTR) metric commonly used in conventional MTC imaging is limited in the assessment of quantitative semisolid macromolecular proton exchange rates and concentrations. In addition, CEST signals measured by MTR asymmetry analysis are unavoidably contaminated by upfield nuclear Overhauser enhancement (NOE) signals of mobile and semisolid macromolecules. To address these issues, we developed an MTC-MR fingerprinting (MTC-MRF) technique to quantify tissue parameters, which further allows an estimation of accurate MTC signals at a certain CEST frequency offset. A pseudorandomized RF saturation scheme was used to generate unique MTC signal evolutions for different tissues and a supervised deep neural network was designed to extract tissue properties from measured MTC-MRF signals. Through detailed Bloch equation-based digital phantom and in vivo studies, we demonstrated that the MTC-MRF can quantify MTC characteristics with high accuracy and computational efficiency, compared to a conventional Bloch equation fitting approach, and provide baseline reference signals for CEST and NOE imaging. For validation, MTC-MRF images were synthesized using the tissue parameters estimated from the deep-learning method and compared with experimentally acquired MTC-MRF images as the reference standard. The proposed MTC-MRF framework can provide quantitative 3D MTC, CEST, and NOE imaging of the human brain within a clinically acceptable scan time.
•A pseudorandomized RF saturation was designed to generate unique MTC signatures.•A deep-learning model was designed to quantify semisolid MTC and water parameters.•A synthetic MRI technique was used for validation of in vivo MTC quantification.•The proposed MTC-MRF framework allowed clean CEST/APT imaging.
Obesity increases the risks of diabetes, hypertension, and cardiovascular diseases, ultimately contributing to mortality. Korean Society for the Study of Obesity (KSSO) was established to improve the ...management of obesity through research and education; to that end, the Committee of Clinical Practice Guidelines of KSSO reviews systemic evidence using expert panels to develop clinical guidelines. The clinical practice guidelines for obesity were revised in 2018 using National Health Insurance Service Health checkup data from 2006 to 2015. Following these guidelines, we added a category, class III obesity, which includes individuals with body mass index (BMI) ≥35 kg/m
. Agreeing with the International Federation for the Surgery of Obesity and Metabolic Disorders, Asian Pacific Chapter consensus, we determined that bariatric surgery is indicated for Korean patients with BMI ≥35 kg/m
and for Korean patients with BMI ≥30 kg/m
who have comorbidities. The new guidelines focus on guiding clinicians and patients to manage obesity more effectively. Our recommendations and treatment algorithms can serve as a guide for the evaluation, prevention, and management of overweight and obesity.
PDF
