The incorporation of low-substituted hydroxypropyl cellulose into solid dispersion systems

While the use of amorphous solid dispersions to improve aqueous solubility is well documented, little consideration has traditionally been given to the finished dosage form. The objective of this study was to evaluate the dissolution performance of amorphous solid dispersions containing a dispersed superdisintegrant with binding properties. KinetiSol® dispersing was used to thermally process hypromellose acetate succinate-based compositions containing the drug substance nifedipine (NIF) and a highly compressible grade of low-substituted hydroxypropyl cellulose (New Binder Disintegrants; NBD-grade). Solid-state analysis demonstrated that compositions were rendered amorphous during processing. Tablets containing intra-dispersion NBD were found to exhibit non-sink dissolution performance similar to milled intermediate, demonstrating excellent disintegration characteristics. Conversely, tablets without intra-dispersion NBD were found to release significantly less NIF during dissolution analysis due to particle agglomeration. It was determined that compressibility and particle wetting increased as the level of intra-dispersion NBD increased.     

Effect of dielectrophoresis on spermatozoa

Application of ultrasound to biological tissues has been identified as a promising cancer treatment technique relying on temporal enhancement of biological membrane permeability via shock wave impact. In the present study, the effects of ultrasonic waves on a 1,2-dipalmitoyl-sn-phosphatidylcholine biological membrane are examined through molecular dynamics simulations. Molecular dynamics methods traditionally employ periodic boundary conditions which, however, restrict the total simulation time to the time required for the shock wave crossing the domain, thus limiting the evaluation of the effects of shock waves on the diffusion properties of the membrane. A novel method that allows capturing both the initial shock wave transit as well as the subsequent longer-timescale diffusion phenomena has been successfully developed, validated and verified via convergence studies. Numerical simulations have been carried out with ultrasonic impulses varying from 0.0 to 0.6 mPa s leading to the conclusion that for impulses ≥0.45 mPa s, no self-recovery of the bilayer is observed and, hence, ultrasound could be applied to the destruction of localized tumor cells. However, for impulses ≤0.3 mPa s, an increase in the transversal diffusivity of the lipids, indicating a consequent enhancement of drug absorption across the membrane, is initially observed followed by a progressive recovery of the initial values, thereby suggesting the advantageous effects of ultrasound on enhancing the chemotherapy efficiency.     

In Vivo Studies of Nanostructure‐Based Photosensitizers for Photodynamic Cancer Therapy

Animal models, particularly rodents, are major translational models for evaluating novel anticancer therapeutics. In this review, different types of nanostructure‐based photosensitizers that have advanced into the in vivo evaluation stage for the photodynamic therapy (PDT) of cancer are described. This article focuses on the in vivo efficacies of the nanostructures as delivery agents and as energy transducers for photosensitizers in animal models. These materials are useful in overcoming solubility issues, lack of tumor specificity, and access to tumors deep in healthy tissue. At the end of this article, the opportunities made possible by these multiplexed nanostructure‐based systems are summarized, as well as the considerable challenges associated with obtaining regulatory approval for such materials. The following questions are also addressed: (1) Is there a pressing demand for more nanoparticle materials? (2) What is the prognosis for regulatory approval of nanoparticles to be used in the clinic?     

Feasibility study of large-scale mass customization 3D printing framework system with a case study on Nanjing Happy Valley East Gate

At present, the development and implementation of digital transformation are the keys to promoting high-quality industry development. The new digital fabrication method of robotic 3D printing is a research area being studied by many to tackle the issue of the declining productivity of traditional construction methods. Although many studies have been done, most of the current 3D printing projects are facing limitations in terms of scale. In order to bridge the gap, this article proposed a mass customization 3D printing framework system for large-scale projects. This article discusses how mass customization is made possible through the joint operation of the FUROBOT software and 3D printing hardware. By taking the east gate of Nanjing Happy Valley Plaza as a case study, the article demonstrates and studies the feasibility of the large-scale mass customization 3D printing framework system.     

Prediction of analyte retention for ion chromatography separations performed using elution profiles comprising multiple isocratic and gradient steps

This study addresses the simulation of ion chromatographic (IC) separations performed under conditions where the elution profile consists of a sequence of isocratic and gradient elution steps (referred to as "complex elution profiles"). First, models for prediction of retention under gradient elution conditions in IC were evaluated using an extensive database of gradient elution retention data. It is shown that one such model is preferred on the basis that it can be used to predict gradient retention times on the basis of isocratic input data. A method is then proposed for using this model for complex elution profiles whereby each step of the elution profile is treated separately and analyte movement through the column is mapped. An empirically based algorithm for predicting peak width under complex elution conditions is also proposed. Evaluation of the suggested approaches was undertaken on a set of 24 analyte anions and 13 analyte cations on 5 different Dionex columns using a range of 5-step complex elution profiles that gave R2 values for correlations between predicted and observed retention times of 0.987 for anions and 0.997 for cations. The simulation of separations of anions and cations using a 3-step complex elution profile is demonstrated, with good correlation between observed and predicted chromatograms. The proposed approach is useful for the rapid development of separations when complex elution profiles are used in IC.     

多层次构成的新加坡公共空间

新加坡城市的历史不到200年,自1972年以来,这座城市经历了由不同优先级和城市议程造成的重大变革。现状的城市结构可以解析为不同的城市图层,由政府谨慎地规划设计和管理整个城市的公共空间由不同的图层交叠构成,对这些公共空间的图层进行总结并分析其动因,力求提供一个理解新加坡城市结构的独特视角。     

Early-life maternal separation and social isolation produce an increase in impulsive action but not impulsive choice.

Early life environment, events, and context, such as mother–offspring relationship, can have profound effects on future behavior and physiology. We investigated the effects of long-term maternal and social separation, through artificial rearing, on adult impulsivity. Rats were maternally reared (MR) or artificially reared (AR) and half of the AR rats were provided with replacement somatosensory stimulation intended to simulate maternal licking. There are at least 2 forms of impulsivity and we compared rats on 1 test of impulsive action (differential reinforcement of low rates of responding—DRL-20s) and 2 tests of impulsive choice (delay discounting and fixed consecutive number schedule—FCN). We found that AR rats are more action impulsive; however, this effect can be reduced by maternal licking-like stimulation. In contrast, AR rats did not display an increase in impulsive choice. Overall, these experiments show that early life maternal and social separation have different effects on the 2 forms of impulsivity. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Validation of left–right method for scattering by a rough surface

Abstract

The method of left-right splitting is studied for the calculation of electromagnetic fields on a finite, perfectly conducting, corrugated rough surface. Surface currents are evaluated for TE and TM polarizations, both on the rough surface and on an extended surface with a rough patch, and these are compared with results from a finite element time-domain calculation. Very good agreement is obtained with one or two terms in the series. The effect of surface truncation is studied for the two polarizations, together with the reflected and transmitted components to the left and right of the rough surface patch, and the TM polarization is found to be relatively insensitive to the surface truncation.