Helical structures with switchable and hierarchical chirality

Chirality is present as a trend of research in biological and chemical communities for it has a significant effect on physiological properties and pharmacological effects. Further, manipulating specific morphological chirality recently has emerged as a promising approach to design metamaterials with tailored mechanical, optical, or electromagnetic properties. However, the realization of many properties found in nature, such as switchable and hierarchical chirality, which allows electromagnetic control of the polarization of light and enhancement of mechanical properties, in man-made structures has remained a challenge. Here, we present helical structures with switchable and hierarchical chirality inspired by origami techniques. We propose eggbox-based chiral units for constructing homogeneous and heterogeneous chiral structures and demonstrate a theoretical approach for tuning the chirality of these structures by modulating their geometrical parameters and for achieving chirality switching through mechanism bifurcation. Finally, by introducing a helical tessellation between the chiral units, we design hierarchical structures with chirality transferring from construction elements to the morphological level and discover a helix with two zero-height configurations during the unwinding process. We anticipate that our design and analysis approach could facilitate the development of man-made metamaterials with chiral features, which may serve in engineering applications, including switchable electromagnetic metamaterials, morphing structures, and bionic robots

Antenna array calibration methods based on simultaneous perturbation

Antenna arrays have gained significant interest in millimetre-wave communication systems as an enabling technology to achieve higher capacity and mitigate the high propagation loss. Such arrays with a large bandwidth need to be efficiently calibrated to maximise their performance. An antenna array calibration method based on a stochastic approximation algorithm and simultaneous perturbation has been developed and the procedures to implement it in both frequency and time domains have been presented. The approaches to define objective functions and establish gradient approximations to fulfill a successful convergence for acquiring calibration coefficients in both domains have been explored. In the time domain implementation, only a fraction of the measurement time was required to calibrate an antenna array of ultrawide bandwidth compared with other methods using a perturbation technique. The effectiveness of the proposed method has been validated via numerical experiments in both domains

Production of Powerful Antioxidant Supplements via Solid-State Fermentation of Wheat (Triticum aestivum Linn.) by Cordyceps militaris

U radu su ispitana antioksidativna svojstva fermentirane pšenice (Triticum aestivum Linn.), ekstrahirane pomoću zakiseljene vode, 70 %-tnog acetona i 70 %-tnog etanola, u usporedbi s kontrolnim uzorkom. Antioksidativna aktivnost fermentirane pšenice, tj. njezina sposobnost uklanjanja 1,1-difenil-2-pikrilhidrazilnih i hidroksilnih radikala, reducirajuća snaga te sposobnost keliranja iona željeza, bila je veća od aktivnosti nefermentirane pšenice. Prinos ekstrakcije, ukupni udjel fenola, flavonoida i slobodnih fenolnih kiselina bili su kudikamo veći u fermentiranoj pšenici. Najveći udjel antioksidativnih spojeva, i to 66,37 mg/g polifenola, izraženih kao ekvivalent galne kiseline, i 32,27 mg/g flavonoida, izraženih kao ekvivalent rutina, te najmanju EC50 vrijednost imao je acetonski ekstrakt fermentirane pšenice. Stoga je zaključeno da se fermentacijom s pomoću gljive Cordyceps militaris može proizvesti zdrava hrana ili sastojak multifunkcionalnih svojstava, što se može upotrijebiti kao prirodni antioksidans u prehrambenoj industriji.The present study has been conducted to evaluate the antioxidant properties of fermented wheat (Triticum aestivum Linn.) extracted using acidified water, 70 % acetone and 70 % ethanol as compared to uninoculated control. Antioxidant activity, measured by the scavenging ability against 1,1-diphenyl-2-picrylhydrazyl radicals and hydroxyl radicals, reducing power and ferrous ion chelating ability was more effective in fermented than unfermented wheat. Furthermore, the extraction yield, total phenolic, total flavonoid and free phenolic acid content were significantly enhanced in fermented wheat. Among the various extracts examined, the acetone extract of the fermented wheat had the highest content of antioxidant compounds (66.37 mg/g as gallic acid equivalent per mass of the extract for polyphenols and 32.27 mg/g as rutin equivalent per mass of flavonoid extract) and antioxidant activity with the lowest EC50 values. Thus, fermentation with Cordyceps militaris can be used as a tool to develop wheat as a health food or ingredient with multi-functional properties which can be used in the food industry as a natural antioxidant

Study of Histopathological and Molecular Changes of Rat Kidney under Simulated Weightlessness and Resistance Training Protective Effect

To explore the effects of long-term weightlessness on the renal tissue, we used the two months tail suspension model to simulate microgravity and investigated the simulated microgravity on the renal morphological damages and related molecular mechanisms. The microscopic examination of tissue structure and ultrastructure was carried out for histopathological changes of renal tissue morphology. The immunohistochemistry, real-time PCR and Western blot were performed to explore the molecular mechanisms associated the observations. Hematoxylin and eosin (HE) staining showed severe pathological kidney lesions including glomerular atrophy, degeneration and necrosis of renal tubular epithelial cells in two months tail-suspended rats. Ultrastructural studies of the renal tubular epithelial cells demonstrated that basal laminas of renal tubules were rough and incrassate with mitochondria swelling and vacuolation. Cell apoptosis in kidney monitored by the expression of Bax/Bcl-2 and caspase-3 accompanied these pathological damages caused by long-term microgravity. Analysis of the HSP70 protein expression illustrated that overexpression of HSP70 might play a crucial role in inducing those pathological damages. Glucose regulated protein 78 (GRP78), one of the endoplasmic reticulum (ER) chaperones, was up-regulated significantly in the kidney of tail suspension rat, which implied that ER-stress was associated with apoptosis. Furthermore, CHOP and caspase-12 pathways were activated in ER-stress induced apoptosis. Resistance training not only reduced kidney cell apoptosis and expression of HSP70 protein, it also can attenuate the kidney impairment imposed by weightlessness. The appropriate optimization might be needed for the long term application for space exploration

Napredak u istraživanju polisaharida izoliranih iz gljive vrste Cordyceps

Cordyceps sinensis (Berk.) Sacc. is one of the well-described fungi that has been used in traditional Chinese medicine for over 700 years. Fungal mycelia contain some polysaccharides that are responsible for their biological activity. C. sinensis has traditionally been cultivated on the high Tibetan plateau as a parasitic fungus growing on caterpillars. However, currently it is being cultivated on some insects and in artificial media. This article deals with the advances in the production, isolation and purification of Cordyceps polysaccharide (CP) in recent years, as well as the structure elucidation and pharmacological action. The article also aims to provide some references for further application and exploitation in the future.Cordyceps sinensis (Berk.) Sacc. jedna je od dobro poznatih gljiva što se više od 700 godina koristi u tradicionalnoj kineskoj medicini. Micelij gljive sadrži polisaharide koji utječu na njezinu biološku aktivnost. C. sinensis se tradicionalno uzgaja na Tibetanskom platou kao parazitska gljiva na gusjenicama leptira, a može se uzgajati i na ličinkama drugih insekata ili na umjetnoj podlozi. U radu se istražuje napredak postignut posljednjih godina u proizvodnji, izolaciji, pročišćavanju, strukturnoj analizi i procjeni farmakološkog djelovanja polisaharida iz gljive Cordyceps. Također je prikazan pregled referencija potrebnih za buduća istraživanja i primjenu tih polisaharida

Interface-engineered paclitaxel-based hollow mesoporous organosilica nanoplatforms for photothermal-enhanced chemotherapy of tumor

Having benefited from the combination of different therapeutic modalities, functionalized nanoplatforms with synergistic strategies have aroused great interest in anticancer treatment. Herein, an engineered, a biodegradable hollow mesoporous organosilica nanoparticle (HMON)-based nanoplatform was fabricated for photothermal-enhanced chemotherapy of tumor. For the first time, we demonstrated that HMONs could serve as nanocarriers for co-delivering of both the paclitaxel and photothermal agent new indocyanine green (IR820), denoted as Paclitaxel/IR820@ HMONs-PEG. The as-prepared nanosystem exhibited a high paclitaxel-loading capacity of 28.4%, much higher than most paclitaxel-loaded nanoformulations. Furthermore, incorporating thioether bonds (S-S) into the HMONs’ framework endowed them with GSH-responsive biodegradation behavior, leading to the controllable release of drugs under a tumor reducing microenvironment, and hindered the premature release of paclitaxel. Upon being irradiated with an NIR laser, the obtained co-delivery nanosystem exhibited great photothermal properties generated from IR820. The fabricated nanocomposites could significantly suppress tumor growth under NIR laser irradiation, as validated by in vitro and in vivo assessments. Combined with outstanding biocompatibility, the constructed nanosystem holds great potential in combinational antitumor therapy

Factors affecting HPV infection in U.S. and Beijing females: A modeling study

BackgroundHuman papillomavirus (HPV) infection is an important carcinogenic infection highly prevalent among many populations. However, independent influencing factors and predictive models for HPV infection in both U.S. and Beijing females are rarely confirmed. In this study, our first objective was to explore the overlapping HPV infection-related factors in U.S. and Beijing females. Secondly, we aimed to develop an R package for identifying the top-performing prediction models and build the predictive models for HPV infection using this R package.MethodsThis cross-sectional study used data from the 2009–2016 NHANES (a national population-based study) and the 2019 data on Beijing female union workers from various industries. Prevalence, potential influencing factors, and predictive models for HPV infection in both cohorts were explored.ResultsThere were 2,259 (NHANES cohort, age: 20–59 years) and 1,593 (Beijing female cohort, age: 20–70 years) participants included in analyses. The HPV infection rate of U.S. NHANES and Beijing females were, respectively 45.73 and 8.22%. The number of male sex partners, marital status, and history of HPV infection were the predominant factors that influenced HPV infection in both NHANES and Beijing female cohorts. However, condom application was not an independent influencing factor for HPV infection in both cohorts. R package Modelbest was established. The nomogram developed based on Modelbest package showed better performance than the nomogram which only included significant factors in multivariate regression analysis.ConclusionCollectively, despite the widespread availability of HPV vaccines, HPV infection is still prevalent. Compared with condom promotion, avoidance of multiple sexual partners seems to be more effective for preventing HPV infection. Nomograms developed based on Modelbest can provide improved personalized risk assessment for HPV infection. Our R package Modelbest has potential to be a powerful tool for future predictive model studies

Identification of Novel Biallelic TLE6 Variants in Female Infertility With Preimplantation Embryonic Lethality

Preimplantation embryonic lethality is a rare cause of primary female infertility. It has been reported that variants in the transducin-like enhancer of split 6 (TLE6) gene can lead to preimplantation embryonic lethality. However, the incidence of TLE6 variants in patients with preimplantation embryonic lethality is not fully understood. In this study, we identified four patients carrying novel biallelic TLE6 variants in a cohort of 28 patients with preimplantation embryonic lethality by whole-exome sequencing and bioinformatics analysis, accounting for 14.29% (4/28) of the cohort. Immunofluorescence showed that the TLE6 levels in oocytes from patients were much lower than in normal control oocytes, suggesting that the variants result in the lower expression of the TLE6 protein in oocytes. In addition, a retrospective analysis showed that the four patients underwent a total of nine failures of in vitro fertilization and intracytoplasmic sperm injection attempts, and one of them became pregnant on the first attempt using donated oocytes. Our study extends the genetic spectrum of female infertility caused by variants in TLE6 and further confirms previously reported findings that TLE6 plays an essential role in early embryonic development. In such case, oocyte donation may be the preferred treatment