49 research outputs found
A Meet-in-the-Middle Attack on Round-Reduced mCrypton Using the Differential Enumeration Technique
This paper describes a meet-in-the-middle (MITM) attack against the round reduced versions of the block cipher mCrypton-64/96/128. We construct a 4-round distinguisher and lower the memory requirement from to using the differential enumeration technique. Based on the distinguisher, we launch a MITM attack on 7-round mCrypton-64/96/128 with complexities of 64-bit blocks and encryptions. Then we extend the basic attack to 8 rounds for mCrypton-128 by adding some key-bridging techniques. The 8-round attack on mCrypton-128 requires a time complexity and a memory complexity . Furthermore, we construct a 5-round distinguisher and propose a MITM attack on 9-round mCrypton-128 with a time complexity of encryptions and a memory complexity of 64-bit blocks
Cryptotanshinone Reverses Reproductive and Metabolic Disturbances in PCOS Model Rats via Regulating the Expression of CYP17 and AR
Objective. To explore the effect of Cryptotanshinone on reversing the reproductive and metabolic disturbances in polycystic ovary syndrome (PCOS) model rats and the possible regulatory mechanisms. Methods. PCOS model rats were induced by subcutaneous injection of dehydroepiandrosterone (DHEA) and verified by histological screening of vaginal exfoliated cells. After Cryptotanshinone intervention, the rats’ body weight and ovary morphological were observed; the serum biochemical assessments were analyzed by radioimmunoassay (RIA) and key genes and proteins related with anabolism of androgen and insulin were detected by Real-Time PCR and Immunohistochemical (IHC). Results. The estrous cyclicity of PCOS model rats was significantly recovered by Cryptotanshinone. The body weight, ovarian coefficient, and ovarian morphology had been improved and the serum biochemical indicators including testosterone (T), androstenedione (A2), luteinizing hormone (LH), LH/follicle stimulating hormone (FSH), sexual binding globulin (SHBG), low density cholesterol (LDL-C), fasting insulin (FINS) were reversed after Cryptotanshinone intervention. Specifically, the levels of Cytochrome P450, 17-a hydroxylase/17,20 lyase (CYP17), and androgen receptor (AR) were downregulated significantly. Conclusions. Our data suggest that Cryptotanshinone could rebalance reproductive and metabolic disturbances in PCOS model rats and could be a potential therapeutic agent for the treatment of PCOS
Vitamin D and cause-specific vascular disease and mortality:a Mendelian randomisation study involving 99,012 Chinese and 106,911 European adults
The United States COVID-19 Forecast Hub dataset
Academic researchers, government agencies, industry groups, and individuals have produced forecasts at an unprecedented scale during the COVID-19 pandemic. To leverage these forecasts, the United States Centers for Disease Control and Prevention (CDC) partnered with an academic research lab at the University of Massachusetts Amherst to create the US COVID-19 Forecast Hub. Launched in April 2020, the Forecast Hub is a dataset with point and probabilistic forecasts of incident cases, incident hospitalizations, incident deaths, and cumulative deaths due to COVID-19 at county, state, and national, levels in the United States. Included forecasts represent a variety of modeling approaches, data sources, and assumptions regarding the spread of COVID-19. The goal of this dataset is to establish a standardized and comparable set of short-term forecasts from modeling teams. These data can be used to develop ensemble models, communicate forecasts to the public, create visualizations, compare models, and inform policies regarding COVID-19 mitigation. These open-source data are available via download from GitHub, through an online API, and through R packages
A Hybrid Model for Air Quality Prediction Based on Data Decomposition
Accurate and reliable air quality predictions are critical to the ecological environment and public health. For the traditional model fails to make full use of the high and low frequency information obtained after wavelet decomposition, which easily leads to poor prediction performance of the model. This paper proposes a hybrid prediction model based on data decomposition, choosing wavelet decomposition (WD) to generate high-frequency detail sequences WD(D) and low-frequency approximate sequences WD(A), using sliding window high-frequency detail sequences WD(D) for reconstruction processing, and long short-term memory (LSTM) neural network and autoregressive moving average (ARMA) model for WD(D) and WD(A) sequences for prediction. The final prediction results of air quality can be obtained by accumulating the predicted values of each sub-sequence, which reduces the root mean square error (RMSE) by 52%, mean absolute error (MAE) by 47%, and increases the goodness of fit (R2) by 18% compared with the single prediction model. Compared with the mixed model, reduced the RMSE by 3%, reduced the MAE by 3%, and increased the R2 by 0.5%. The experimental verification found that the proposed prediction model solves the problem of lagging prediction results of single prediction model, which is a feasible air quality prediction method
Fabrication strategy for amphiphilic microcapsules with narrow size distribution by premix membrane emulsification
Amphiphilic co-polymer, which can maintain the stability of proteins and increase the protein loading efficiency, is considered as an exploring-worthy biodegrade polymer for drug delivery. However, amphiphilic microcapsules prepared by conventional methods, such like mechanical stirring and spray-drying methods, exhibit broad size distributions due to its hydrophilic sequences, leading to poor reproducibility. In this study, we employed poly(monomethoxypoly ethylene glycol-co-D,L-lactide) (mPEG-PLA, PELA), one of common amphiphilic polymers, as model to focus on investigating the process parameters and mechanisms to prepare PELA microcapsules with narrow size distribution and regular sphericity by combining premix membrane emulsification and double emulsion technique. The coarse double emulsion with broad size distribution was repeatedly pressed through Shirasu Porous Glass (SPG) membrane with relatively high pressure to form the fine emulsion with narrow size distribution. Then, the microcapsules with narrow size distribution can be obtained by solvent extraction method. It was found that it was more difficult to obtain PELA microcapsules with narrow size distribution and smooth surface due to its amphiphilic property, compared with the cases of PLA and PLGA. The smooth surface morphology was found to be related to several factors including internal water phase with less volume, slower stirring rate during solidification and using ethyl acetate as oil phase. It was also found that mass ratio of hydrophilic mPEG, stabilizer PVA concentration in external water phase and transmembrane pressure played important role on the distribution of microcapsules size. The suitable preparation conditions were determined as follows: for the membrane with pore size of 2.8 mu m, the mass ratio of PLA/mPEG was 19:1. volume ratio of W(1)/O was 1:10 and O/W(2) was 1:5. PVA concentration (w/v) was 1.0%, magnetic stirring rate during solidification was 60 rpm and 300 kPa was chosen as transmembrane pressure. There was a linear relationship between the diameter of microcapsules and the pore size of the membranes. Finally, by manipulating the process parameters, PELA microcapsules with narrow size distributions (coefficient of variation was less than 15%), smooth morphology and various sizes, were obtained. Most importantly, the key factors affecting fabrication have been revealed and mechanisms were illustrated in detail, which would shed light on the research of amphiphilic polymer formulation. (C) 2011 Elsevier B.V. All rights reserved
Chitosan-based mucosal adjuvants: Sunrise on the ocean
Mucosal vaccination, which is shown to elicit systemic and mucosal immune responses, serves as a non-invasive and convenient alternative to parenteral administration, with stronger capability in combatting diseases at the site of entry. The exploration of potent mucosal adjuvants is emerging as a significant area, based on the continued necessity to amplify the immune responses to a wide array of antigens that are poorly immunogenic at the mucosal sites. As one of the inspirations from the ocean, chitosan-based mucosal adjuvants have been developed with unique advantages, such as, ability of mucosal adhesion, distinct trait of opening the junctions to allow the paracellular transport of antigen, good tolerability and biocompatibility, which guaranteed the great potential in capitalizing on their application in human clinical trials. In this review, the state of art of chitosan and its derivatives as mucosal adjuvants, including thermo-sensitive chitosan system as mucosal adjuvant that were newly developed by author's group, was described, as well as the clinical application perspective. After a brief introduction of mucosal adjuvants, chitosan and its derivatives as robust immune potentiator were discussed in detail and depth, in regard to the metabolism, safety profile, mode of actions and preclinical and clinical applications, which may shed light on the massive clinical application of chitosan as mucosal adjuvant. (C) 2015 Elsevier Ltd. All rights reserved
Facile one-pot emulsion/sol-gel method for preparing wrinkled silica microspheres
The present manuscript describes a facile and versatile method for preparing uniform wrinkled silica microspheres with diameters of tens of microns. The method comprises a one-pot emulsion/sol-gel method using silica precursors of organosilane and tetraethoxysilane. By controlling the sol-to-gel transition of the silica precursors, a series of silica microspheres based on uniform emulsion droplets was synthesized by membrane emulsification. The silica microspheres had a variety of surface morphologies ranging from smooth, maze-like wrinkles to polygon-like ravines. It was possible to alter the surface morphologies of the microspheres by controlling the amount of organosilane in the dispersed phase and the amount of ammonia catalyst in the continuous phase of the emulsion. The grooves on the wrinkled microspheres were able to trap polymer nanoparticles of matching size, thereby demonstrating the potential usefulness of the microspheres in separation science and drug delivery. (C) 2021 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V
Comparison of covalent and physical immobilization of lipase in gigaporous polymeric microspheres
Lipase (EC 3.1.1.3) is a versatile enzyme which has been widely used in ester-reaction industries. We have previously discovered that gigaporous polystyrene (PST) microspheres can be used as a novel immobilization carrier for lipase. In this work, a series of gigaporous microspheres with different densities of epoxy group including poly(glycidyl methacrylate) (PGMA) and poly(styrene-co-glycidyl methacrylate) [P(ST-GMA)] were evaluated as lipase immobilization carriers, which were also compared with gigaporous PST microspheres and the commercial immobilized lipase Novozym 435. Lipase immobilized in gigaporous PGMA microspheres showed the highest activity yield, reusability, and stability as well as the best affinity for the substrate. The characterizations of adsorption curves, the change of epoxy group amounts, and hydrophobic-hydrophilic properties of the microspheres were carried out to investigate the interaction between lipase molecules and carriers. It was found that covalent binding played a key role in improving the properties of lipase immobilized in gigaporous PGMA microspheres