Quality by design (QbD) in the formulation and optimization of liquid crystalline nanoparticles (LCNPs): A risk based industrial approach.

The intersection of lipid-based nanoparticles and lyotropic liquid crystals has provided a novel type of nanocarrier system known as 'lipid-based lyotropic liquid crystals' or 'liquid crystalline nanoparticles' (LCNPs). The unique advantages and immense popularity of LCNPs can be exploited in a better way if the formulation of LCNPs is done using the approach of quality by design (QbD). QbD is a systematic method that can be utilized in formulation development. When QbD is applied to LCNPs formulation, it will proffer many unique advantages, such as better product and process understanding, the flexibility of process within the design space, implementation of more effective and efficient control strategies, easy transfer from bench to bedside, and more robust product. In this work, the application of QbD in the formulation of LCNPs has been explored. The elements of QbD, viz. quality target product profile, critical quality attributes, critical material attributes, critical process parameters, quality risk management, design of experiments, and control strategy for the development of LCNPs have been explained in-depth with case studies. The present work will help the reader to understand the nitty-gritties in the application of QbD in the formulation of LCNPs, and provide a base for QbD-driven formulation of LCNPs with a regulatory perspective.

Contribución de Cuba y del Instituto de Medicina Tropical "Pedro Kourí" para evitar las muertes por dengue / Contribution of Cuba and Pedro Kouri Tropical Medicine Institute to preventing mortality from dengue

El dengue es una enfermedad viral transmitida por mosquitos que puede ser causa de gravedad y muerte. No existe droga antiviral reconocida como eficaz. Sin embargo, las regularidades de esta enfermedad han permitido la identificación de signos de alarma que anuncian extravasación de plasma e inminencia del choque. El inicio precoz del tratamiento de los pacientes mediante la reposición de líquidos cristaloides por vía intravenosa ha demostrado ser una medida efectiva y salvadora. Se necesita capacitación sistemática y acciones de reorganización de la atención médica en función de la epidemia. Se expone la contribución de los profesionales del Instituto de Medicina Tropical Pedro Kourí y otras instituciones cubanas a ese empeño(AU)

Dengue is a viral disease transmitted by mosquitoes which may be severe and cause death. No antiviral drug has been recognized as effective. However, the regularities of this condition have made it possible to identify warning signs announcing plasma leakage and the imminence of shock. Early start of treatment with intravenous crystalloid fluid replacement has proven to be an effective, life-saving measure. Systematic training actions and reorganization of medical care are required during an epidemic. The paper describes the contribution of professionals from Pedro Kouri Tropical Medicine Institute and other Cuban institutions to this effort(AU)

[Peculiarities of pilot's perception of flight information presented on on-board liquid crystal displays].

The article deals with results of experimental studies conducted on flight testing desk and covering peculiarities of pilot's perception of flight information presented on on-board liquid crystal display in dependence on changes speed and update rate of the screen. The authors determine frequency characteristics of information update rate, that achieve acceptable quality of the flight parameters perception in accordance with the changes speed. Vigorous maneuvering with high angular velocities of changed parameters of roll and pitch causes visual distortions that are connected with poor frequency of information update rate, deteriorate piloting quality and can cause flight unsafety.

The impact of computer display performance on the quality of digital radiographs: a review.

Radiography makes an essential contribution to the processes of examination, diagnosis and treatment planning in dentistry. While the use of film-based imaging still predominates in dentistry, digital imaging is gaining wider acceptance and the use of this modality is anticipated to expand in the future. Two concerns associated with this transition have been raised in the literature. The first of these is the dissatisfaction experienced by many dental professionals with quality of digital radiographs when compared to plain film. In addition, there are indications that practitioners feel limited in their understanding of those factors impacting on digital image quality. One key area highlighted in the literature as having a significant influence on digital radiographic quality and interpretation concerns the performance of the display device. Within the last decade, research derived from the fields of medical radiology and physics have demonstrated that suboptimally performing displays degrade image quality, thereby increasing the potential for compromised diagnostic outcomes. In the field of medicine, this has resulted in the establishment of standards applicable to computer displays used in diagnostic radiology. Conversely, limited guidelines exist in the field of dentistry. The aim of this review is to provide an outline of these standards and highlight the important relationship between computer display performance and digital image quality.

Achieving precise display timing in visual neuroscience experiments.

In experimental visual neuroscience brief presentations of visual stimuli are often required. Accurate knowledge of the durations of visual stimuli and their signal shapes is important in psychophysical experiments with humans and in neuronal recordings with animals. In this study we measure and analyze the changes in luminance of visual stimuli on standard computer monitors. Signal properties of the two most frequently used monitor technologies, cathode ray tube (CRT) and liquid crystal display (LCD) monitors, are compared, and the effects of the signal shapes on the stated durations of visual stimuli are analyzed. The fundamental differences between CRT and LCD signals require different methods for the specification of durations, especially for brief stimulus presentations. In addition, stimulus durations on LCD monitors vary over different monitor models and are not even homogeneous with respect to different luminance levels on a single monitor. The use of LCD technology for brief stimulus presentation requires extensive display measurements prior to the experiment.

Visual evoked potentials with CRT and LCD monitors: when newer is not better.

BACKGROUND: The stimulus for pattern reversal visual evoked potentials (PRVEP) has traditionally been delivered by a cathode ray tube (CRT) monitor. Liquid crystal display (LCD) monitors have become more affordable and are being used instead of CRT monitors for many applications. We tested the hypothesis that LCD monitors were equivalent to CRT monitors when used for PRVEP. METHODS: Monocular, full field PRVEP with a 32' check size were obtained in six normal subjects with a CRT monitor and LCD monitors having 2 msec, 8 msec, and 30 msec response times. The average P100 latency with the CRT screen was compared to the latencies with the LCD screens. RESULTS: The mean P100 latency of the CRT monitor was 107.7 (+/-6.6) ms, for the LCD 2 msec monitor was 115.7 (+/-6.9; p < 0.0001) ms, for the LCD 8 msec monitor was 118.5 (+/-6.5; p < 0.0001) ms, and the LCD 30 msec monitor was 156.8 (+/-6.8; p < 0.0001) ms. CONCLUSIONS: Currently available liquid crystal display (LCD) monitors do not provide data comparable to cathode ray tube (CRT) monitors. LCD monitors cannot replace CRT monitors for pattern reversal visual evoked potentials unless new normative data are obtained.

A comparison of the suitability of cathode ray tube (CRT) and liquid crystal display (LCD) monitors as visual stimulators in mfERG diagnostics.

The aim of this study was to determine up to which extent the specific characteristics of cathode ray tube (CRT) and liquid crystal display (LCD) monitors influence the retinal biosignal when used as stimulators in ocular electrophysiology. In a conventional CRT monitor, each pixel lights up only for a duration of a few milliseconds during each frame. In contrast, liquid crystal displays are quasi-static, i.e. each pixel has a constant luminance during the whole length of the frame, but lights up only with a certain delay after the trigger. These different display characteristics may affect the mfERG signal. The temporal and spatial luminance distributions of a CRT and an LCD monitor were measured in white flashes. The total amount of emitted light was calculated by integration of the intensity versus time curves. By means of an mfERG recording system (RETIsystem, Roland Consult, Brandenburg, Germany) first-order kernel (FOK) mfERG signals were computed and then analysed using customized MATLAB (TheMathWorks, Natick, MA, USA) software. With the two stimulator monitors, differences in the mfERG signal were observed. The latencies of mfERG responses recorded with the LCD monitor were significantly increased by 7.1 ms for N1 and 9.5 ms for P1 compared to the CRT. Due to a higher luminance, the N1 amplitude was significantly higher by approx. 2 dB in measurements with the LCD monitor while no significant difference could be detected with regard to the more contrast sensitive P1 amplitude. When using LCD monitors as stimulators the increase in latencies and differences in the luminance versus time profile must be taken into account. Prior to clinical application, the establishment of guidelines for the use of LCD monitors is recommended.