An improved LC–MS/MS method for determination of docetaxel and its application to population pharmacokinetic study in Chinese cancer patients

Because of its unpredictable side effects and efficacy, the anticancer drug docetaxel (DTX) requires improved characterisation of its pharmacokinetic profiles through population pharmacokinetic studies. A sensitive and rugged LC–MS/MS method for the detection of DTX in human plasma was developed and optimised using paclitaxel as an internal standard (IS). The plasma samples underwent rapid extraction using hybrid solid-phase extraction-protein precipitation. The analyte and IS were separated with an isocratic system on a Zorbax Eclipse Plus C₁₈ column using water containing 0.05% acetic acid along with 20 μM of sodium acetate and methanol (30/70, v/v) as the mobile phase. Quantification was performed using a triple quadrupole mass spectrometer through multiple reaction monitoring in positive mode, using the m/z 830.3 → 548.8 and m/z 876.3 → 307.7 transitions for DTX and paclitaxel, respectively. The range of the calibration curve was 1–500 ng/mL for DTX, and the linear correlation coefficient was >0.99. The accuracies ranged from −4.6 to 4.2%, and the precision was no higher than 7.0% for the analytes. No significant matrix effect was observed. Both DTX and the IS showed considerable recovery. This method was finally applied to the establishment of a population pharmacokinetic model to optimise the clinical use of DTX.     

Na原子链表面等离激元特性的含时密度泛函研究

本文用含时密度泛函理论研究了线性Na原子链的表面等离激元机理.主要在原子尺度下模拟计算了体系随着原子数增加及原子间距变化的集体激发过程.研究发现线性原子链有一个普遍的特性——存在一个纵模和两个横模.两个横模一般在实验上很难被观测到.纵模随着原子链长度增加,能量红移的同时,该纵模主峰的强度呈线性增长.随着原子个数的增加,端点模式(TE)开始蓝移,能量和偶极强度都逐渐趋向饱和.横模能量被劈裂的原因概括如下:(一)每个位置的电子受到的势不同,在两端的电子受到的势要比在中间的电子受到的势要高,因此两端的电荷积累也比中间多;(二)端点存在悬挂键,所以中间的电子-电子间相互作用与端点的不一样,这两方面又都与原子间距d有关.     

Transition‐Metal‐Free Trifluoromethylthiolation of N‐Heteroarenes

A general and efficient methodology for the direct transition metal free trifluoromethylthiolation of a broad range of biologically relevant N‐heteroarenes is reported employing abundant sodium chloride as the catalyst. This method is operationally simple, exhibits high functional group tolerance, and does not require protecting groups.     

Hybrid systems for oral delivery of a therapeutic neuropeptide

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CuI-catalyzed tandem synthesis of thioethers using aryl halides,electron-deficient alkenes,and sodium iso-propyl xanthogenate

A ligand-free, CuI-catalyzed protocol was developed for the one-step preparation of Michael adducts of aromatic thiols in high yields by reacting a mixture of an aryl halide and an electron-deficient alkene with sodium iso-propyl xanthogenate.     

Green synthesis of the 1-substituted 1H-1, 2, 3, 4-tetrazoles over bifunctional catalyst based on copper intercalated into Mg/Al hydrotalcite modified magnetite nanoparticles

An effective one-pot, convenient process for the synthesis of 1- substituted 1H-tetrazoles from triethyl orthoformate, amines, and sodium azide is described using copper (II) doped and immobilized on functionalized magnetic hydrotalcite (Fe₃O₄/HT-NH₂ Cu^II) as a novel recyclable catalyst. The application of this catalyst allows the synthesis of a variety of tetrazoles in good to excellent yields in water. The new catalyst was characterized using Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), thermogravimetric analysis (TGA), vibration sample magnetometry (VSM) and inductively coupled plasma analysis (ICP-OES). This new procedure offers several advantages such as short operational simplicity, practicability, and applicability to various substrates and the absence of any tedious workup or purification. The loading amount of Cu^II (doped and immobilized) on functionalized magnetic hydrotalcite was indicated to be 4.66 mmol g⁻¹, obtained from the ICP-OES analysis. Also, the excellent catalytic performance, thermal stability, and separation of the catalyst make it an excellent heterogeneous system and a useful alternative to other heterogeneous catalysts. Also, the catalyst could be magnetically separated and reused six times without significant loss of catalytic activity.     

Afterglow Implant for Arterial Embolization and Intraoperative Imaging

Transcatheter arterial embolization (TAE) is wildly used in clinical treatments. However, the online monitoring of the thrombosis formation is limited due to the challenges of the direct visualization of embolic agents and the real-time monitoring of dynamic blood flow. Thus, we developed a photochemical afterglow implant with strong afterglow intensity and a long lifetime for embolization and imaging. The liquid pre-implant injected into the abdominal aorta of mice was rapidly transformed into a hydrogel in situ to embolize the blood vessel. The vascular embolism position can be observed by the enhanced afterglow of the fixed implant, and the long lifetime of afterglow can also be used to monitor the effect of embolization. This provides an excellent candidate in bio-imaging to avoid the autofluorescence interference from continuous light excitation. The study suggests the potential usefulness of the implant as an embolic agent in TAE and artery imaging during a surgical procedure.     

Addition of SiO2 to the operation of a polyimide cathode in a sodium battery

The effect of the addition of SiO₂ nanoparticles on the properties of a polyimide cathode was explored by CV, XPS, and galvanostatic cycling methods. The capacity and average cycling potential of the cell increased in the presence of SiO₂. By quantum chemical modeling, it was shown that SiO₂ nanoparticles served as a framework for polyimide, which retained its fixed structure upon metalation with sodium.     

Biosynthesis of Pd/MnO2 nanocomposite using Solanum melongena plant extract and its application for the one‐pot synthesis of 5‐substituted 1H‐tetrazoles from aryl halides

In this work, for the first time, Solanum melongena plant extract was used for the green synthesis of Pd/MnO₂ nanocomposite via reduction osf Pd(II) ions to Pd(0) and their immobilization on the surface of manganese dioxide (MnO₂) nanoparticles (NPs) as an effective support. The synthesized nanocomposite were characterized by various analytical techniques such as Fourier transform infrared (FT‐IR), X‐ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), energy dispersive X‐ray spectroscopy (EDS) and UV–Vis spectroscopy. The catalytic activity of Pd/MnO₂ nanocomposite was used as a heterogeneous catalyst for the one‐pot synthesis of 5‐substituted 1H‐tetrazoles from aryl halides containing various electron‐donating or electron‐withdrawing groups in the presence of K ₄ [Fe (CN) ₆ ] as non‐toxic cyanide source and sodium azide. The products were obtained in good yields via a simple methodology and easy work‐up. The nanocatalyst can be recycled and reused several times with no remarkable loss of activity.     

Co3+-Rich Na1.95CoP2O7 Phosphates as Efficient Bifunctional Catalysts for Oxygen Evolution and Reduction Reactions in Alkaline Solution

Implementing sustainable energy conversion and storage technologies is highly reliant on crucial oxygen electrocatalysis, such as the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). However, the pursuit of low cost, energetic efficient and robust bifunctional catalysts for OER and ORR remains a great challenge. Herein, the novel Na-ion-deficient Na_2−xCoP₂O₇ catalysts are proposed to efficiently electrocatalyze OER and ORR in alkaline solution. The engineering of Na-ion deficiency can tune the electronic structure of Co, and thus tailor the intrinsically electrocatalytic performance. Among the sodium cobalt phosphate catalysts, the Na_1.95CoP₂O₇ (NCPO5) catalyst exhibits the lowest ΔE (E_J10,OER−E_J−1,ORR) of only 0.86 V, which favorably outperforms most of the reported non-noble metal catalysts. Moreover, the Na-ion deficiency can stabilize the phase structure and morphology of NCPO5 during the OER and ORR processes. This study highlights the Na-ion deficient Na_2−xCoP₂O₇ as a promising class of low-cost, highly active and robust bifunctional catalysts for OER and ORR.