Improved dispersion of attapulgite nanorods in polymer with graphene oxide nanosheets

To improve the dispersion stability of rod-like attapulgite (ATT) in polymers, a small amount of graphene oxide (GO) nanosheets were employed as a supporter to fix ATT before introducing into polymer. The ATT nanorods were found attached tightly and dispersed uniformly on the GO nanosheets from TEM images of GO-ATT hybrids. The dispersion stability of ATT in water was also improved after being attached on GO nanosheets due to the abundant hydrophilic groups of GO, which was paramount for introducing them into polymers through water blending method. Poly(vinyl alcohol) (PVA) was then chosen to be reinforced by these GO-supported ATT via water blending method. Compared to the heavy aggregation of neat ATT in PVA, a homogeneous distribution of ATT nanorods in the matrix was achieved by introducing them in the form of GO-ATT, indicating a favorable assisted dispersion effect of GO nanosheets for ATT. Furthermore, PVA/GO-ATT nanocomposites containing only 2 wt% GO-ATT exhibited a significantly increase of 41.4 and 83.6 % in tensile strength and storage modulus, respectively.     

Stability of pharmaceutical salts in solid oral dosage forms

Using pharmaceutical salts in solid dosage forms can raise stability concerns, especially salt dissociation which can adversely affect the product performance. Therefore, a thorough understanding of the salt instability encountered in solid-state formulations is imperative to ensure the product quality. The present article uses the fundamental theory of acid base, ionic equilibrium, relationship of pH and solubility as a starting point to illustrate and interpret the salt formation and salt disproportionation in pharmaceutical systems. The criteria of selecting the optimal salt form and the underlying theory of salt formation and disproportionation are reviewed in detail. Factors influencing salt stability in solid dosage forms are scrutinized and discussed with the case studies. In addition, both commonly used and innovative strategies for preventing salt dissociations in formulation, on storage and during manufacturing will be suggested herein. This article will provide formulation scientists and manufacturing engineers an insight into the mechanisms of salt disproportionation and salt formation, which can help them to avoid and solve the instability issues of pharmaceutical salts in the product design.     

Engineered Nanoplatelets for Targeted Delivery of Plasminogen Activators to Reverse Thrombus in Multiple Mouse Thrombosis Models

Rapid cut-off of blood supply in diseases involving thrombosis is a major cause of morbidity and mortality worldwide. However, the current thrombolysis strategies offer limited results due to the therapeutics' short half-lives, low targeting ability, and unexpected bleeding complications. Inspired by the innate roles of platelets in hemostasis and pathological thrombus, platelet membrane-camouflaged polymeric nanoparticles (nanoplatelets) are developed for targeting delivery of the thrombolytic drug, recombinant tissue plasminogen activator (rt-PA), to local thrombus sites. The tailor-designed nanoplatelets efficiently accumulate at the thrombi in pulmonary embolism and mesenteric arterial thrombosis model mice, eliciting a significantly enhanced thrombolysis activity compared to free rt-PA. In addition, the nanoplatelets exhibit improved therapeutic efficacy over free rt-PA in an ischemic stroke model. Analysis of in vivo coagulation indicators suggests the nanoplatelets might possess a low risk of bleeding complications. The hybrid biomimetic nanoplatelets described offer a promising solution to improve the efficacy and reduce the bleeding risk of thrombolytic therapy in a broad spectrum of thrombosis diseases.     

A Graphdiyne Oxide-Based Iron Sponge with Photothermally Enhanced Tumor-Specific Fenton Chemistry

Fenton reaction-mediated oncotherapy is an emerging strategy which uses iron ions to catalytically convert endogenous hydrogen peroxide into hydroxyl radicals, the most reactive oxygen species found in biology, for efficient cancer therapy. However, Fenton reaction efficiency in tumor tissue is typically limited due to restrictive conditions. One strategy to overcome this obstacle is to increase the temperature specifically at the tumor site. Herein, a tumor-targeting iron sponge (TTIS) nanocomposite based on graphdiyne oxide, which has a high affinity for iron is described. TTIS can accumulate in tumor tissue by decoration with a tumor-targeting polymer to enable tumor photoacoustic and magnetic resonance imaging. With its excellent photothermal conversion efficiency (37.5%), TTIS is an efficient photothermal therapy (PTT) agent. Moreover, the heat produced in the process of PTT can accelerate the release of iron ions from TTIS and simultaneously enhance the efficiency of the Fenton reaction, thus achieving a combined PTT and Fenton reaction-mediated cancer therapy. This work introduces a graphdiyne oxide-based iron sponge that exerts an enhanced antitumor effect through PTT and Fenton chemistry.     

An Antioxidant Enzyme Therapeutic for COVID-19

The COVID-19 pandemic has taken a significant toll on people worldwide, and there are currently no specific antivirus drugs or vaccines. Herein it is a therapeutic based on catalase, an antioxidant enzyme that can effectively breakdown hydrogen peroxide and minimize the downstream reactive oxygen species, which are excessively produced resulting from the infection and inflammatory process, is reported. Catalase assists to regulate production of cytokines, protect oxidative injury, and repress replication of SARS-CoV-2, as demonstrated in human leukocytes and alveolar epithelial cells, and rhesus macaques, without noticeable toxicity. Such a therapeutic can be readily manufactured at low cost as a potential treatment for COVID-19.     

甜菜碱改性聚乙烯胺在活性染料染色中的作用及影响

通过1-（3-二甲氨基丙基）-3-乙基碳二亚胺盐酸盐（EDC）/N-羟基琥珀酰亚胺（NHS）接枝法使用甜菜碱对聚乙烯胺进行化学接枝,并固定在棉纤维上使其阳离子化,解决了传统染色过程中大量使用无机盐造成的水污染问题。与传统使用无机盐上染法相比,由于棉纤维阳离子化增加了染料与纤维之间的亲和力,该方法上染率由40.8%提高至78.0%,匀染性和染色牢度均得到提升,染色废水的化学需氧量(COD_cr)由1267 mg/L降低至221 mg/L。方法操作简单效果优良,符合当前绿色生产的理念,可以被广泛应用于棉纤维材料的染色。     

不同种类颗粒物对切割器性能评价的影响研究

在切割器捕集效率评价过程中,选用不同种类的颗粒物可能会对切割器的评价结果产生不同的影响。通过搭建基于静态箱法的切割器评价系统,可测量并拟合得到切割器的捕集效率曲线。分别使用多分散的亚利桑那尘及不同粒径的单分散聚苯乙烯标准微球对国产及进口的PM_2.5切割器、进口的PM₁切割器进行评价,对比评价结果发现使用亚利桑那尘评价、拟合得到的切割器50%切割粒径与使用单分散聚苯乙烯微球得到的结果存在差异,并且根据空气动力学粒径谱仪的粒径识别原理对产生此结果的原因进行分析。该研究结果对于切割器的性能评价有一定的科学意义,可为环保监测数据准确性的提升提供参考。     

Effect of Tantalum ion doping on the structure and electrical properties of Bi3Ti1.5W0.5O9-Bi4Ti3O12 intergrowth bismuth-layered ceramics

Journal of Materials Science: Materials in Electronics - Bi7Ti4.5-xTaxW0.5O21 (BTW-BIT-xTa, x?=?0.00, 0.05, 0.10, 0.15, 0.20, 0.30) intergrowth bismuth-layered ceramics were fabricated...