A probable aculeacin A acylase from the Ralstonia solanacearum GMI1000 is N-acyl-homoserine lactone acylase with quorum-quenching activity

<p>Abstract</p> <p>Background</p> <p>The infection and virulence functions of diverse plant and animal pathogens that possess quorum sensing systems are regulated by <it>N</it>-acylhomoserine lactones (AHLs) acting as signal molecules. AHL-acylase is a quorum quenching enzyme and degrades AHLs by removing the fatty acid side chain from the homoserine lactone ring of AHLs. This blocks AHL accumulation and pathogenic phenotypes in quorum sensing bacteria.</p> <p>Results</p> <p>An <it>aac </it>gene of undemonstrated function from <it>Ralstonia solanacearum </it>GMI1000 was cloned, expressed in <it>Escherichia coli</it>; it inactivated four AHLs that were tested. The sequence of the 795 amino acid polypeptide was considerably similar to the AHL-acylase from <it>Ralstonia </it>sp. XJ12B with 83% identity match and shared 39% identity with an aculeacin A acylase precursor from the gram-positive actinomycete <it>Actinoplanes utahensis</it>. Aculeacin A is a neutral lipopeptide antibiotic and an antifungal drug. An electrospray ionisation mass spectrometry (ESI-MS) analysis verified that Aac hydrolysed the amide bond of AHL, releasing homoserine lactone and the corresponding fatty acids. However, ESI-MS analysis demonstrated that the Aac could not catalyze the hydrolysis of the palmitoyl moiety of the aculeacin A. Moreover, the results of MIC test of aculeacin A suggest that Aac could not deacylate aculeacin A. The specificity of Aac for AHLs showed a greater preference for long acyl chains than for short acyl chains. Heterologous expression of the <it>aac </it>gene in <it>Chromobacterium violaceum </it>CV026 effectively inhibited violacein and chitinase activity, both of which were regulated by the quorum-sensing mechanism. These results indicated that Aac could control AHL-dependent pathogenicity.</p> <p>Conclusion</p> <p>This is the first study to find an AHL-acylase in a phytopathogen. Our data provide direct evidence that the functioning of the <it>aac </it>gene (NP520668) of <it>R. solanacearum </it>GMI1000 is via AHL-acylase and not via aculeacin A acylase. Since Aac is a therapeutic potential quorum-quenching agent, its further biotechnological applications in agriculture, clinical and bio-industrial fields should be evaluated in the near future.</p

A Selection Model to Logistic Centers Based on TOPSIS and MCGP Methods: The Case of Airline Industry

The location selection of a logistics center is a crucial decision relating to cost and benefit analysis in airline industry. However, it is difficult to be solved because there are many conflicting and multiple objectives in location problems. To solve the problem, this paper integrates fuzzy technique for order preference by similarity to an ideal solution (TOPSIS) and multichoice goal programming (MCGP) to obtain an appropriate logistics center from many alternative locations for airline industry. The proposed method in this paper will offer the decision makers (DMs) to set multiple aspiration levels for the decision criteria. A numerical example of application is also presented

Molecular Diagnosis of Periprosthetic Joint Infection by Quantitative RT-PCR of Bacterial 16S Ribosomal RNA

The diagnosis of periprosthetic joint infection is sometimes straightforward with purulent discharge from the fistula tract communicating to the joint prosthesis. However it is often difficult to differentiate septic from aseptic loosening of prosthesis because of the high culture-negative rates in conventional microbiologic culture. This study used quantitative reverse transcription polymerase chain reaction (RT-qPCR) to amplify bacterial 16S ribosomal RNA in vitro and in 11 clinical samples. The in vitro analysis demonstrated that the RT-qPCR method was highly sensitive with the detection limit of bacterial 16S rRNA being 0.148 pg/μl. Clinical specimens were analyzed using the same protocol. The RT-qPCR was positive for bacterial detection in 8 culture-positive cases (including aerobic, anaerobic, and mycobacteria) and 2 culture-negative cases. It was negative in one case that the final diagnosis was confirmed without infection. The molecular diagnosis of bacterial infection using RT-qPCR to detect bacterial 16S rRNA around a prosthesis correlated well with the clinical findings. Based on the promising clinical results, we were attempting to differentiate bacterial species or drug-resistant strains by using species-specific primers and to detect the persistence of bacteria during the interim period before the second stage reimplantation in a larger scale of clinical subjects

Terahertz nonlinear hall rectifiers based on spin-polarized topological electronic states in 1T-CoTe2

The zero-magnetic-field nonlinear Hall effect (NLHE) refers to the second-order transverse current induced by an applied alternating electric field; it indicates the topological properties of inversion-symmetry-breaking crystals. Despite several studies on the NLHE induced by the Berry-curvature dipole in Weyl semimetals, the direct current conversion by rectification is limited to very low driving frequencies and cryogenic temperatures. The nonlinear photoresponse generated by the NLHE at room temperature can be useful for numerous applications in communication, sensing, and photodetection across a high bandwidth. In this study, observations of the second-order NLHE in type-II Dirac semimetal CoTe2 under time-reversal symmetry are reported. This is determined by the disorder-induced extrinsic contribution on the broken-inversion-symmetry surface and room-temperature terahertz rectification without the need for semiconductor junctions or bias voltage. It is shown that remarkable photoresponsivity over 0.1 A W−1, a response time of approximately 710 ns, and a mean noise equivalent power of 1 pW Hz−1/2 can be achieved at room temperature. The results open a new pathway for low-energy photon harvesting via nonlinear rectification induced by the NLHE in strongly spin–orbit-coupled and inversion-symmetry-breaking systems, promising a considerable impact in the field of infrared/terahertz photonicsPID2019–109525RB-I00, CEX2018-000805-M, EU’s H2020 NFFA-Europe (n. 654360), and NFFA-Europe-Pilot (10100741

Women with endometriosis have higher comorbidities: Analysis of domestic data in Taiwan

AbstractEndometriosis, defined by the presence of viable extrauterine endometrial glands and stroma, can grow or bleed cyclically, and possesses characteristics including a destructive, invasive, and metastatic nature. Since endometriosis may result in pelvic inflammation, adhesion, chronic pain, and infertility, and can progress to biologically malignant tumors, it is a long-term major health issue in women of reproductive age. In this review, we analyze the Taiwan domestic research addressing associations between endometriosis and other diseases. Concerning malignant tumors, we identified four studies on the links between endometriosis and ovarian cancer, one on breast cancer, two on endometrial cancer, one on colorectal cancer, and one on other malignancies, as well as one on associations between endometriosis and irritable bowel syndrome, one on links with migraine headache, three on links with pelvic inflammatory diseases, four on links with infertility, four on links with obesity, four on links with chronic liver disease, four on links with rheumatoid arthritis, four on links with chronic renal disease, five on links with diabetes mellitus, and five on links with cardiovascular diseases (hypertension, hyperlipidemia, etc.). The data available to date support that women with endometriosis might be at risk of some chronic illnesses and certain malignancies, although we consider the evidence for some comorbidities to be of low quality, for example, the association between colon cancer and adenomyosis/endometriosis. We still believe that the risk of comorbidity might be higher in women with endometriosis than that we supposed before. More research is needed to determine whether women with endometriosis are really at risk of these comorbidities

The Prevalence and Impact of Fake News on COVID-19 Vaccination in Taiwan: Retrospective Study of Digital Media

BackgroundVaccination is an important intervention to prevent the incidence and spread of serious diseases. Many factors including information obtained from the internet influence individuals’ decisions to vaccinate. Misinformation is a critical issue and can be hard to detect, although it can change people's minds, opinions, and decisions. The impact of misinformation on public health and vaccination hesitancy is well documented, but little research has been conducted on the relationship between the size of the population reached by misinformation and the vaccination decisions made by that population. A number of fact-checking services are available on the web, including the Islander news analysis system, a free web service that provides individuals with real-time judgment on web news. In this study, we used such services to estimate the amount of fake news available and used Google Trends levels to model the spread of fake news. We quantified this relationship using official public data on COVID-19 vaccination in Taiwan. ObjectiveIn this study, we aimed to quantify the impact of the magnitude of the propagation of fake news on vaccination decisions. MethodsWe collected public data about COVID-19 infections and vaccination from Taiwan's official website and estimated the popularity of searches using Google Trends. We indirectly collected news from 26 digital media sources, using the news database of the Islander system. This system crawls the internet in real time, analyzes the news, and stores it. The incitement and suspicion scores of the Islander system were used to objectively judge news, and a fake news percentage variable was produced. We used multivariable linear regression, chi-square tests, and the Johnson-Neyman procedure to analyze this relationship, using weekly data. ResultsA total of 791,183 news items were obtained over 43 weeks in 2021. There was a significant increase in the proportion of fake news in 11 of the 26 media sources during the public vaccination stage. The regression model revealed a positive adjusted coefficient (β=0.98, P=.002) of vaccine availability on the following week's vaccination doses, and a negative adjusted coefficient (β=–3.21, P=.04) of the interaction term on the fake news percentage with the Google Trends level. The Johnson-Neiman plot of the adjusted effect for the interaction term showed that the Google Trends level had a significant negative adjustment effect on vaccination doses for the following week when the proportion of fake news exceeded 39.3%. ConclusionsThere was a significant relationship between the amount of fake news to which the population was exposed and the number of vaccination doses administered. Reducing the amount of fake news and increasing public immunity to misinformation will be critical to maintain public health in the internet age

Two-dimensional superconductivity and magnetotransport from topological surface states in AuSn4 semimetal

Surface states of topological semimetals may give rise to unusual transport properties and topological superconductivity. Here, the H-T phase diagram of AuSn4 is experimentally established, displaying 2D superconductivity, Bose metal behavior, and normal-state magnetotransport driven by surface states

Results of Conversion from Failed Austin-Moore Hemiarthroplasty to Cementless Total Hip Arthroplasty in Octogenarian Patients with Advanced Acetabular Erosion: A Minimum of 5 Years of Follow-Up

Austin-Moore hemiarthroplasty (HA) had been selectively used for elderly patients with femoral neck fractures. With increasing life span and activity, the sequela of Austin-Moore HA make the implant no longer favorable. The treatment of failed Austin-Moore HA with advanced acetabular erosion is challenging; however, little has been published regarding this topic. The aim of this study was to evaluate the mid-term results of using cementless total hip arthroplasty (THA) in octogenarians. Between 2008 and 2011, 47 patients (32 women and 15 men) with an average age of 86 years (range 83-89 years) were enrolled in this retrospective study. After an average follow-up period of 6.2 years (range 5.0-7.8 years), no migration or loosening of the cup or femoral stem was found. Harris hip scores improved from 36 (range 15-42) preoperatively to 87 (range 80-90). There were no complications directly associated with the procedure except for superficial infections in two patients. Our results suggest that using cementless THA can result in favorable radiographic and clinical outcomes in octogenarian patients

Nephroprotective Role of Chrysophanol in Hypoxia/Reoxygenation-Induced Renal Cell Damage via Apoptosis, ER Stress, and Ferroptosis

Acute kidney injury (AKI) is caused by hypoxia-reoxygenation (H/R), which is a kidney injury produced by a variety of causes, resulting in the remaining portion of the kidney function being unable to maintain the balance for performing the tasks of waste excretion metabolism, and electrolyte and acid-base balance. Many studies have reported the use of Chinese medicine to slow down the progression and alleviate the complications of chronic renal failure. Chrysophanol is a component of Rheum officinale Baill, a traditional Chinese medicine that has been clinically used to treat renal disease. We aimed to study the nephroprotective effect of chrysophanol on hypoxia/ reoxygenation (H/R)-induced cell damage. The results showed that chrysophanol prevented H/R-induced apoptosis via downregulation of cleaved Caspase-3, p-JNK, and Bax but upregulation of Bcl-2 expression. In contrast, chrysophanol attenuated H/R-induced endoplasmic reticulum (ER) stress via the downregulation of CHOP and p-IRE1α expression. Our data demonstrated that chrysophanol alleviated H/R-induced lipid ROS accumulation and ferroptosis. Therefore, we propose that chrysophanol may have a protective effect against AKI by regulating apoptosis, ER stress, and ferroptosis