다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

Over the last two decades, fluorine substitution has become one of the essential structural traits in modern pharmaceuticals. Thus, about half of the most successful drugs (blockbuster drugs) contain fluorine atoms. In this review, we profile 17 fluorine-containing drugs approved by the food and drug administration (FDA) in 2018. The newly approved pharmaceuticals feature several types of aromatic F and CF3 , as well as aliphatic (CF2 ) substitution, offering advances in the treatment of various diseases, including cancer, HIV, malarial and smallpox infections.

Fluorine-Containing Drugs Approved by the FDA in 2018

Luminescence nanothermometry enables accurate, remote, and all-optically-based thermal sensing. Notwithstanding its fast development, there are serious obstacles hindering reproducibility and reliable quantitative assessment of nanothermometers, which impede the intentional design, optimization and use of these sensors. These issues include ambiguities or absence of established universal rules for quantitative evaluation, incorrect assumptions about the mechanisms behind the thermal response of the sensors as well as the dependence of the nanothermometers readout on external conditions and host materials themselves. In this perspective article, we discuss these problems and propose a series of standardization guidelines to be followed. This critical discourse constitutes the first required step towards the ubiquitous acceptance, by the scientific community, of luminescence thermometry as a reliable tool for remote temperature determination in numerous practical biomedical implementations.

Standardizing luminescence nanothermometry for biomedical applications

In 1883 Kjeldahl devised a method for the determination of nitrogen, which has become a classical measurement in analytical chemistry and has been used extensively over the past 130 years. In the original method, sulfuric acid alone was used as a digestion medium. The use of a catalyst in Kjeldahl digestion accelerates oxidation and completes the digestion to allow the subsequent determination of nitrogen. Mercury (its use being in decline because of environmental concerns), selenium, and copper are the catalysts of choice, though for certain applications titanium has found some usage. Short digestion times in association with maximum nitrogen recovery may be achieved by using a methodology based on experimental design and response surfaces, with microwave digestion processes, and with the aid of the couple sulfuric acid-hydrogen peroxide without catalyst. The quantification of distilled ammonia is generally achieved by titration; the ammonia is absorbed in an excess of boric acid, followed by titration w...

An Overview of the Kjeldahl Method of Nitrogen Determination. Part I. Early History, Chemistry of the Procedure, and Titrimetric Finish

Lanthanide (Ln3+)-based nanoparticles (NPs) with light emission in the ultraviolet (UV), visible, and near-infrared (NIR) region under NIR excitation are emerging multifunctional players in the biomedical field. Excitation and emission wavelengths matching the NIR biological transparency windows (700-1870 nm) set the basis for deeper penetration depth into biological tissues due to less absorption, higher resolution as a result of reduced scattering, and improved imaging contrast due to tissue autofluorescence minimization; all being inevitable requirements for optical in vivo bioimaging. Moreover, frequency-conversion in Ln3+-based NPs is sensitive to their thermal environment, thus allowing for application as optical temperature sensors. Additional heating capability opens the pathway to self-monitored optical agents with potential for photothermal therapies (PTTs). UV-visible emitting upconverting nanoparticles (UCNPs) are of particular interest for applications in photodynamic therapies (PDTs) owing to their capability to trigger various photochemical processes upon NIR excitation. It is the aim of this review to highlight the most recent achievements and advances in the field of Ln3+-based NPs as frequency-converting materials for biomedical applications and to identify current trends as well as remaining challenges. Special focus will be set on the most recently presented Ln3+-based systems whose potential has been evaluated in vitro and in vivo as NIR-to-NIR bioimaging probes, NIR-operating nanothermometers and -heaters as well as photochemical agents.

Optical nanoprobes for biomedical applications: shining a light on upconverting and near-infrared emitting nanoparticles for imaging, thermal sensing, and photodynamic therapy

Over the last 100-120 years, due to the ever-increasing importance of fluorine-containing compounds in modern technology and daily life, the explosive development of the fluorochemical industry led to an enormous increase of emission of fluoride ions into the biosphere. This made it more and more important to understand the biological activities, metabolism, degradation, and possible environmental hazards of such substances. This comprehensive and critical review focuses on the effects of fluoride ions and organofluorine compounds (mainly pharmaceuticals and agrochemicals) on human health and the environment. To give a better overview, various connected topics are also discussed: reasons and trends of the advance of fluorine-containing pharmaceuticals and agrochemicals, metabolism of fluorinated drugs, withdrawn fluorinated drugs, natural sources of organic and inorganic fluorine compounds in the environment (including the biosphere), sources of fluoride intake, and finally biomarkers of fluoride exposure.

Chemical Aspects of Human and Environmental Overload with Fluorine

Fluoride in teas of different types and forms and the exposure of humans to fluoride with tea and diet

In a proof-of-concept study, we assessed different analytical and spectroscopic parameters for stability screening of differently sized β-NaYF4:20 mol % Yb3+, 2 mol % Tm3+ upconversion nanoparticles (UCNPs) exemplarily in the bioanalytically relevant buffer phosphate buffered saline (PBS; pH 7.4) at 37 and 50 °C. This included the potentiometric determination of the amount of released fluoride ions, surface analysis with X-ray photoelectron spectroscopy (XPS), and steady-state and time-resolved fluorescence measurements. Based on these results, the luminescence lifetime of the 800 nm upconversion emission was identified as an optimum parameter for stability screening of UCNPs and changes in particle surface chemistry.

Optically Detected Degradation of NaYF4:Yb,Tm-Based Upconversion Nanoparticles in Phosphate Buffered Saline Solution.

The dissolution of upconverting AYF4:Yb,Tm (A = Na or K) nanoparticles (UCNPs) in aqueous media was systematically studied. UCNPs with a cubic structure and sizes of between 10 and 33 nm were synthesized solvothermally in ethylene glycol at 200 °C. The UCNPs of both compositions showed an upconversion fluorescence emission characteristic of Tm3+. The effects of the A cation, the particle size, the temperature, the pH, and the composition of the aqueous medium on the dissolution of the UCNPs were evaluated. The degree of dissolution was determined from the fraction of dissolved fluoride (F–) using potentiometry. Unexpectedly, the composition of aqueous media had the most significant effect on the dissolution of the UCNPs. The highest degree of dissolution and rate were measured for the phosphate-buffered saline (PBS), which can be explained by the formation of stable lanthanide compounds with phosphates. The degree of dissolution was much lower in water and in the phthalate buffer, which was attributed to ...

Dissolution Mechanism of Upconverting AYF4:Yb,Tm (A = Na or K) Nanoparticles in Aqueous Media

The chemical stability of upconverting, lanthanide-doped, fluoride nanoparticles in aqueous media, which shows great potential in bioimaging, was studied. The partial dissolution of selected nanoparticles (NaYF4, LaF3 and GdF3) co-doped with Yb3+ and Tm3+ was detected and compared with respect to their size, chemical composition and structure.

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Maja Ponikvar-Svet

Papers

Chemical Aspects of Human and Environmental Overload with Fluorine

Fluoride in teas of different types and forms and the exposure of humans to fluoride with tea and diet

Optically Detected Degradation of NaYF4:Yb,Tm-Based Upconversion Nanoparticles in Phosphate Buffered Saline Solution.

Dissolution Mechanism of Upconverting AYF4:Yb,Tm (A = Na or K) Nanoparticles in Aqueous Media

Dissolution of upconverting fluoride nanoparticles in aqueous suspensions