小分子糖负载血小板+冻干保护剂混合悬液的相变点测定与屏蔽实验研究

目的测定冻干血小板长期保存预冻程序和所依据的制品相变点温度并摸索相应屏蔽相变点的最佳冷冻曲线。方法研制出小分子糖负载血小板+冻干保护剂混合悬液,使用速率程序降温仪分析测定该混合悬液样品的相变点温度;根据测得的相变点温度,设计屏蔽相变点的预冻程序,根据温度变化曲线,判断相变点屏蔽结果。结论该混合悬液样品的相变点温度为(-13.56±2.05)℃;据此相变点温度所设计的3种相应的屏蔽相变点的预冻程序中,程序3为最佳冷冻曲线。结果获得了小分子糖负载血小板+冻干保护剂混合悬液的相变点温度及相应的屏蔽相变点的最佳预冻程序。     

健康理念的发展与现代研究之悖论

健康理念随不同历史时期的文化观念而改变。以观察和推理为基本认知手段的中医学形成了真人、至人、圣人、贤人的健康理念。虽然同样是观察自然，以自然哲学作为原理进行论述，但由于构建理论体系的不同，西方医学传统的健康理念就是身体不生病。文艺复兴之后，生物医学模式形成，身体不生病即是健康这一理念得到了强化。自20世纪70年代开始，西医学的医学模式开始转变，WHO也修定了健康的定义，同时循证医学也开始崛起。这些新出现的健康理念，是向中医学健康理念的靠拢。然而，在实际研究及应用，尤其是对于循证医学所制定的分级标准，有些人片面强调“金标准”，违背了循证医学创始者的初衷，而且所谓的“金标准”也小适应于医学的新模式和健康的新理念。这此都严重阻碍了医学新模式下医学科学研究的进步。     

Pseudo‐extravasation rate constant of dynamic susceptibility contrast‐MRI determined from pharmacokinetic first principles

Dynamic susceptibility contrast‐magnetic resonance imaging (DSC‐MRI) is widely used to obtain informative perfusion imaging biomarkers, such as the relative cerebral blood volume (rCBV). The related post‐processing software packages for DSC‐MRI are available from major MRI instrument manufacturers and third‐party vendors. One unique aspect of DSC‐MRI with low‐molecular‐weight gadolinium (Gd)‐based contrast reagent (CR) is that CR molecules leak into the interstitium space and therefore confound the DSC signal detected. Several approaches to correct this leakage effect have been proposed throughout the years. Amongst the most popular is the Boxerman–Schmainda–Weisskoff (BSW) K₂ leakage correction approach, in which the K₂ pseudo‐first‐order rate constant quantifies the leakage. In this work, we propose a new method for the BSW leakage correction approach. Based on the pharmacokinetic interpretation of the data, the commonly adopted R₂* expression accounting for contributions from both intravascular and extravasating CR components is transformed using a method mathematically similar to Gjedde–Patlak linearization. Then, the leakage rate constant (K_L) can be determined as the slope of the linear portion of a plot of the transformed data. Using the DSC data of high‐molecular‐weight (~750 kDa), iron‐based, intravascular Ferumoxytol (FeO), the pharmacokinetic interpretation of the new paradigm is empirically validated. The primary objective of this work is to empirically demonstrate that a linear portion often exists in the graph of the transformed data. This linear portion provides a clear definition of the Gd CR pseudo‐leakage rate constant, which equals the slope derived from the linear segment. A secondary objective is to demonstrate that transformed points from the initial transient period during the CR wash‐in often deviate from the linear trend of the linearized graph. The inclusion of these points will have a negative impact on the accuracy of the leakage rate constant, and even make it time dependent.     

Nanogold-Based Sensing of Environmental Toxins: Excitement and Challenges

There have been tremendous advances in the past ten years on the development of various nanomaterials-based sensors for detection of environmental toxins. Nanogold is of special interest because of its unique shape- and size-dependent optical properties, hyper-quenching ability, super surface-enhanced Raman and dynamic light scattering, and surface-modifiability by small organic molecules and biomolecules. These unique optical properties of nanogold have been explored for ultra-sensitive detection, while its surface-modifiability has been explored for selectivity. In general, the nanogold-based sensors are highly selective and sensitive along with simple sample preparation and sensor design. In this review article, we intend to capture some of the recent advances in nanogold-based sensor development and mechanistic studies, especially for bacteria, heavy metals, and nitroaromatic compounds. Undoubtedly, these developments will generate a lot of excitement for environmental scientists and toxicologists as well as the general public.     

Mercuric Chloride Poisoning Due to Ingestion of a Stool Fixative

Abstract

We present a case of ingestion of a commonly used stool fixative containing 675?mg of mercuric chloride per 15 mL vial. Early chelator therapy with dimercaprol and aggressive hydration were initiated and the patient remained asymptomatic. Safety packaging of this product is recommended.     

Single-step green synthesis of gold conjugated polyphenol nanoparticle using extracts of Saudi’s myrrh: Their characterization,molecular docking and essential biological applications

The progress in the innovative nanocrystal synthesis process by using environmentally benign and low-priced nontoxic chemicals, solvents, and renewable sources remains a challenging task for researchers worldwide. The majority of the existing synthesis techniques engage in the potentially dangerous, for either human health or the environment. Current investigation has been centered on green synthesis processes to create novel nanomaterials, which are eco-friendly as well as safer for sustainable marketable feasibility. The current work provides the green synthesis method for gold nanoparticle (GNPs) synthesis using Commiphora myrrh (C.myrrh) extract. This simple method includes 6 ml of HAuCl₄·3H₂O treated with 4 ml C.myrrh extract having pH 4.5 after 80 min at 25 °C temperature. In this novel method, green synthesized GNPs characterized by UV–Vis, X^_ray diffraction spectroscopy (XRD), zeta potential, fourier transform infrared (FT^_IR), high^_resolution transmission electron microscopy (HR^_TEM), energy dispersive X^_ray spectroscopy (EDXA), and dynamic light scattering (DLS). During the development successful antioxidant assay, the DPPH assay was applied. The cell toxicity of green synthesized GNPs was evaluated following an MTT assay against HCT-116 (colon cancer) and MCF-7 (breast cancer).Besides molecular docking in the δ-elemene for inhibitor to VEGFR‐2 domain revealed more negative docking score (?3.976) which is an excellent binding affinity to the C.myrrh@GNP. The synthesized GNPs showed antidiabetic, antibiotic, and antibacterial properties and anti^_inflammatory inhibition against inhibiting COX-1, and COX-2 enzymes. In addition, molecular docking by Lindestrene (?3.806) and Furanoeudesma-1,3-dien (?3.912) against COX1 and COX2 respectively showed strong binding affinity. The molecular docking study evidenced the anti-inflammatory and cell toxicity study.     

On the mechanism of AuCl3-catalyzed synthesis of highly substituted furans from 2-(1-alkynyl)-2-alken-1-ones with nucleophiles: A DFT study

The mechanism of AuCl₃-catalyzed synthesis of highly substituted furans from 2-(1-alkynyl)-2-alken-1-ones with nucleophiles have been investigated using density functional theory calculations done at the BHandHLYP/6-31G(d, p) (lanl2dz for Au) level of theory. Our calculations suggest that the first step of the cycle is the cyclization of the carbonyl oxygen onto the triple bond to form a new and stable five-membered resonance structure of an oxonium ion and a carbocation intermediate. Furthermore, the six-membered carbocation intermediate proposed by Larock et al. was found and characterized as a transition structure on the potential energy surface. The attack of the carbonyl oxygen to the gold coordinated alkynes results in the formation of a resonance structure intermediate which upon subsequent trapping with alcohols followed by migration of hydrogen atom results in the formation of the final products and regeneration of the catalyst. Our computational results are in consistent with the experimental observations of Larock et al. for the AuCl₃-catalyzed synthesis of highly substituted furans from 2-(1-alkynyl)-2-alken-1-ones with nucleophiles.     

ACCESS化学发光仪残余回收试剂临床应用价值评价

目的:对ACCESS化学发光仪残余回收试剂进行临床应用评价.方法:收集残余试剂并按要求储存,对50例患者样本在同等条件下分别用ACCESS2化学发光仪原装试剂和ACCESS化学发光仪回收试剂进行AFP、CEA、SF、T3、T4、FT3、FT4、TSH等项目的检测,并对回收试剂与原装试剂进行可比性分析评价.结果:回收试剂...     

复方甘草甜素氯化钠注射液的细菌内毒素检查

目的探讨复方甘草甜素氯化钠注射液中细菌内毒素的检查方法。方法选择一定灵敏度的鲎试剂考察复方甘草甜素氯化钠注射液对细菌内毒素检查的干扰作用。结果复方甘草甜素氯化钠注射液对细菌内毒素反应有干扰,将其稀释成1∶8的浓度可消除其干扰作用。结论在1∶8的稀释度下,可用灵敏度为0.25EU.mL-1的鲎试剂进行细菌内毒素检查,从而控制细菌内毒素的限量。