The mechanism of tetraploidization in tree peony, and its implications for speciation and evolution of genus Paeonia L.

IntroductionPolyploidization is not only an important driving force for plant speciation and evolution, but also an effective approach for plant domestication and improvement. Polyploid taxa are quite common in Paeonia section Paeonia (herbaceous peonies), but very rare in section Moutan (tree peonies), which are known as the ‘king of flowers’.MethodsIn this paper, we studied the origination of a tetraploid tree peony, P. × lemoinei ‘Golden Era’ (‘GE’, AABB), by comparing its karyotype with its seed parent, P. × lemoinei ‘Golden Isles’ (‘GI’, AB), based on genomic in situ hybridization (GISH) and rDNA fluorescence in situ hybridization (FISH). The meiosis behaviors of ‘GI’ were observed to make clear the cytogenetic process of unreduced (2n) gamete generation.ResultsFour chromosomes with inter-genome translocations were identified in ‘GE’, two of which might be reciprocal translocations. The 2n female gametes via first division restitution (FDR) from ‘GI’ might play an important role in tetraploidization of ‘GE’.DisucssionThe distant hybridization between intersterile species from different subsections of section Moutan probably promotes the tetraploidization of tree peonies by facilitating 2n gamete production. The mechanism of tetraploidization in section Moutan is highly consistent with that in section Paeonia, but is inseparable with the assist from mankind. The divergence of life history between tree peonies and herbaceous peonies is speculated to contribute to the different level of polyploidization, and distinct tempo of speciation and evolution, between section Moutan and section Paeonia in genus Paeonia. These findings bring new insights to polyploid breeding, speciation and evolution in genus Paeonia

The Static and Dynamic Mechanical Properties of Magnetorheological Silly Putty

A novel magnetorheological material defined as magnetorheological Silly Putty (MRSP) is prepared by dispersing soft magnetic particles into Silly Putty matrix with shear stiffening property. Static mechanical properties including creep and stress relaxation and dynamic rheological properties of MRSPs are tested by rheometer. The experimental results indicate that the external magnetic field exerts significant influence on the creep and relaxation behaviors. Moreover, the storage modulus of MRSPs increases sharply in response to the external stimuli of increasing angular frequency automatically and can be enhanced by external magnetic field. Besides, temperature plays a key role in shear stiffening and magnetorheological effect of MRSPs. Furthermore, considering the obstruction to the particle chains formation induced by Silly Putty matrix, a nonperforative particle aggregated chains model is proposed. The model curve is in consistency with experimental data, which means it can describe magnetoinduced behavior of MRSPs well

Concurrent chemoradiotherapy was associated with a higher severe late toxicity rate in nasopharyngeal carcinoma patients compared with radiotherapy alone: a meta-analysis based on randomized controlled trials

BACKGROUND: To investigate the incidence and risk of severe late toxicity with concurrent chemoradiotherapy (CCRT) in nasopharyngeal carcinoma patients. METHODS: Eligible studies included prospective randomized controlled trials (RCTs) evaluating CCRT versus radiotherapy alone in patients with nasopharyngeal carcinoma and in which data on severe late toxicities were available. Random effects or fixed effect models were applied to obtain the summary incidence, relative risks (RRs) and 95% confidence intervals (CIs). RESULTS: Five RCTs with 1102 patients with NPC were included in this analysis. The summary incidence of overall severe late toxicities in patients receiving CCRT was 30.7% (95% CI, 18–47.2%) and the incidence of radiotherapy alone group was 21.7% (95% CI, 13.3–33.4%). The use of concurrent chemotherapy was associated with an increased risk of severe late toxicities, with a RR of 1.349 (95% CI, 1.108–1.643; P = 0.005). As for specific late toxicity, CCRT significantly increased the risk of ear deafness/otitis (RR = 1.567; 95% CI, 1.192–2.052), but other late toxicities were not significantly different. Patients receiving concurrent chemotherapy regimens with 3-week high-dose cisplatin (HC) have a higher risk of ear deafness/otitis (RR = 1.672; 95% CI, 1.174–2.382; P = 0.026). However, there was no significant increase in the RR of severe ear complication with the addition of non-3-week high-dose cisplatin (nonHC) regimens (RR = 1.433; 95% CI, 0.946–2.171; P = 0.095). CONCLUSION: With the present evidence, the addition of concurrent chemotherapy seems to increase the risk of severe late toxicities in patients with NPC, especially when using HC regimen for the occurrence of severe ototoxicity

Performance of Variable Negative Stiffness MRE Vibration Isolation System

Magnetorheological elastomer (MRE) vibration isolation devices can improve a system’s vibration response via adjustable stiffness and damping under different magnetic fields. Combined with negative stiffness design, these MRE devices can reduce a system’s stiffness and improve the vibration control effect significantly. This paper develops a variable negative stiffness MRE isolation device by combining an improved separable iron core with laminated MREs. The relationship between the negative stiffness and the performance of the device is obtained by mathematical transformation. Its vibration response under simple harmonic excitation at small amplitude and the impact of the volume fraction of soft magnetic particles on the isolation system are also analyzed. The results show that the negative stiffness produced by the magnetic force is a major factor affecting the capacity of the isolation system. Compared to devices of the same size, the isolation system equipped with low-particle volume fraction MREs demonstrates better performance

Outcomes and prognostic factors for patients with cervical esophageal cancer undergoing definitive radiotherapy or chemoradiotherapy

Cervical esophageal cancer (CEC) is uncommon, accounting for less than 5% of all esophageal cancers. The management of CEC is controversial. This study investigated treatment outcomes and prognostic factors of survival in CEC patients undergoing definitive radiotherapy or concurrent chemoradiotherapy (CCRT). Ninety-one CEC patients were treated by intensity-modulated radiation therapy (IMRT) and three-dimensional conformal radiation therapy (3DCRT) between July 2007 and September 2017. The mean prescription dose was 64 Gy (range 54-70 Gy) delivered as 1.8-2.2 Gy per fraction per day, 5 days a week. Out of 91 patients, 34 received concurrent cisplatin-based chemotherapy (CT) including 18 patients who also received neoadjuvant CT. Overall survival (OS), locoregional failure-free survival (LRFFS), and progression-free survival (PFS) were estimated by the Kaplan–Meier method. Prognostic factors of survival were determined in univariate (log-rank test) and multivariate (Cox proportional hazard model) analysis. Treatment-related toxicity was also assessed. Median follow-up time for all patients was 19 months. Two-year OS, LRFFS and PFS of all patients were 58.2%, 52.5% and 48.1%, respectively. Clinical stage was an independent prognostic factor for OS (HR = 2.35, 95% CI: 1.03-5.37, p = 0.042), LRFFS (HR = 3.84, 95% CI: 1.38-10.69, p = 0.011), and PFS (HR = 2.68, 95% CI: 1.11-6.45, p = 0.028). Hoarseness was an independent prognostic factor for OS (HR = 2.10, 95% CI: 1.05-4.19, p = 0.036). CCRT was independently associated with better LRFFS (HR = 0.33, 95% CI: 0.14-0.79, p = 0.012). 3DCRT and IMRT with concurrent CT is well-tolerated and may improve local tumor control in CEC patients. Advanced clinical stage and hoarseness are adverse prognostic factors for OS, LRFFS, and PFS in CEC

Novel Inhibitor Design for Hemagglutinin against H1N1 Influenza Virus by Core Hopping Method

The worldwide spread of H1N1 avian influenza and the increasing reports about its resistance to the current drugs have made a high priority for developing new anti-influenza drugs. Owing to its unique function in assisting viruses to bind the cellular surface, a key step for them to subsequently penetrate into the infected cell, hemagglutinin (HA) has become one of the main targets for drug design against influenza virus. To develop potent HA inhibitors, the ZINC fragment database was searched for finding the optimal compound with the core hopping technique. As a result, the Neo6 compound was obtained. It has been shown through the subsequent molecular docking studies and molecular dynamic simulations that Neo6 not only assumes more favorable conformation at the binding pocket of HA but also has stronger binding interaction with its receptor. Accordingly, Neo6 may become a promising candidate for developing new and more powerful drugs for treating influenza. Or at the very least, the findings reported here may provide useful insights to stimulate new strategy in this area

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Clopidogrel Plus Aspirin vs Aspirin Alone in Patients With Acute Mild to Moderate Stroke

Importance Dual antiplatelet therapy has been demonstrated to be superior to single antiplatelet in reducing recurrent stroke among patients with transient ischemic attack or minor stroke, but robust evidence for its effect in patients with mild to moderate ischemic stroke is lacking. Objective To evaluate whether dual antiplatelet therapy is superior to single antiplatelet among patients with mild to moderate ischemic stroke. Design, Setting, and Participants This was a multicenter, open-label, blinded end point, randomized clinical trial conducted at 66 hospitals in China from December 20, 2016, through August 9, 2022. The date of final follow-up was October 30, 2022. The analysis was reported on March 12, 2023. Of 3065 patients with ischemic stroke, 3000 patients with acute mild to moderate stroke within 48 hours of symptom onset were enrolled, after excluding 65 patients who did not meet eligibility criteria or had no randomization outcome. Interventions Within 48 hours after symptom onset, patients were randomly assigned to receive clopidogrel plus aspirin (n = 1541) or aspirin alone (n = 1459) in a 1:1 ratio. Main Outcomes and Measures The primary end point was early neurologic deterioration at 7 days, defined as an increase of 2 or more points in National Institutes of Health Stroke Scale (NIHSS) score, but not as a result of cerebral hemorrhage, compared with baseline. The superiority of clopidogrel plus aspirin to aspirin alone was assessed based on a modified intention-to-treat population, which included all randomized participants with at least 1 efficacy evaluation regardless of treatment allocation. Bleeding events were safety end points. Results Of the 3000 randomized patients, 1942 (64.6%) were men, the mean (SD) age was 65.9 (10.6) years, median (IQR) NIHSS score at admission was 5 (4-6), and 1830 (61.0%) had a stroke of undetermined cause. A total of 2915 patients were included in the modified intention-to-treat analysis. Early neurologic deterioration occurred in 72 of 1502 (4.8%) in the dual antiplatelet therapy group vs 95 of 1413 (6.7%) in the aspirin alone group (risk difference −1.9%; 95% CI, −3.6 to −0.2; P = .03). Similar bleeding events were found between 2 groups. Conclusions and Relevance Among Chinese patients with acute mild to moderate ischemic stroke, clopidogrel plus aspirin was superior to aspirin alone with regard to reducing early neurologic deterioration at 7 days with similar safety profile. These findings indicate that dual antiplatelet therapy may be a superior choice to aspirin alone in treating patients with acute mild to moderate stroke.Trial RegistrationClinicalTrials.gov Identifier: NCT0286900

An improved proportional topology optimization method combining a polarized material interpolation scheme and Heaviside threshold function

An improved proportional topology optimization (IPTO) method is proposed in this work. The main improvement of this method is that the conventional solid isotropic material with penalization (SIMP)-based material interpolation scheme is replaced by a polarized material interpolation scheme, and the Heaviside threshold function is adopted based on the original proportional topology optimization (PTO) method. By using this approach, the minimum compliance problem can be solved without requiring the numerical derivation of the sensitivity function. To verify the feasibility and effectiveness of the proposed method, two-dimensional (2D) and three-dimensional (3D) cantilevers and L-bracket beams are used as examples. The 2D results obtained by the IPTO method are compared with those obtained by the PTO and SIMP methods. Numerical examples demonstrate that IPTO can acquire better objective function values and more ideal topology structures compared to PTO and SIMP. Furthermore, IPTO offers significant advantages over PTO and SIMP in terms of convergence speed and the ability to suppress intermediate density elements. Additionally, this method enables topology optimization design under multiple working conditions. Therefore, it provides an effective approach for structural topology optimization in research and engineering applications. With appropriate adjustment, this method can also be applied to composite material design and heat conduction design