Electromagnetically-induced transparency and slow light in room temperature <Superscript>4</Superscript>He*

Electromagnetically-induced transparency (EIT) in three-level Λ-systems is based on quantum interference effects involving coherence between the two lower levels, which allow propagation of a resonant probe light beam in the presence of a strong coupling field. We have observed transparency in ultra-narrow (<10 kHz) windows at the resonant 1.083 μm transition for purely electronic spins in gaseous ⁴He* at room temperature. Slow light is an interesting outcome of the EIT phenomenon due to extreme dispersion within the narrow transparency window. We have obtained group delays of about 4 μs in a 2.5 cm long He* cell. A complete theoretical analysis explains our observations emphasizing the positive role of collisions. Slow light with 1-GHz Doppler broadening opens the door to applications of controllable large-bandwidth delays in radars.     

Oxidative Stress and Antioxidative Therapy in Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is clinically characterized by a progressive increase in pulmonary artery pressure, followed by right ventricular hypertrophy and subsequently right heart failure. The underlying mechanism of PAH includes endothelial dysfunction and intimal smooth muscle proliferation. Numerous studies have shown that oxidative stress is critical in the pathophysiology of PAH and involves changes in reactive oxygen species (ROS), reactive nitrogen (RNS), and nitric oxide (NO) signaling pathways. Disrupted ROS and NO signaling pathways cause the proliferation of pulmonary arterial endothelial cells (PAECs) and pulmonary vascular smooth muscle cells (PASMCs), resulting in DNA damage, metabolic abnormalities, and vascular remodeling. Antioxidant treatment has become a main area of research for the treatment of PAH. This review mainly introduces oxidative stress in the pathogenesis of PAH and antioxidative therapies and explains why targeting oxidative stress is a valid strategy for PAH treatment.     

A rapid and sensitive UPLC–MS/MS method for the determination of zanubrutinib in beagle plasma and its application in pharmacokinetics

A reliable and sensitive ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) method was developed for the determination of zanubrutinib in the plasma of beagle dogs. The column used was an Acquity BEH C₁₈ column (2.1 mm × 50 mm, 1.7 μm), maintained at 40°C with an injection volume of 2 μl. The gradient elution program was as follows: 0–1 min, 10–10% A; 1–1.1 min, 10–90% A; 1.1–2.1 min, 90–90% A; 2.1–2.2 min, 90–10% A; 2.2–3.0 min, 10–10% A. Mobile phase A was 0.1% formic acid, B was acetonitrile, and the total analysis time was 3 min. The mass spectrometry was performed in positive ion mode, and the scanning mode was multi-reaction monitoring mode with electrospray ionization as the ion source; m/z 472.2 → 455.01 for zanubrutinib and m/z 441.03 → 137.99 for ibrutinib (internal standard). The plasma samples were processed by protein precipitation. The standard curve showed good linearity (r² = 0.999 8) in the range of 1.0–1,000 ng/ml (zanubrutinib) with a low limit of quantification of 1 ng/ml. Also, the intra-day and inter-day precision (RSD) was <5.88% and the accuracy (RE) ranged from −1.56 to 1.08%; the recoveries of zanubrutinib in beagle plasma ranged from 90.12 to 93.53% (RSD 1.67–6.42%) and the ME values of zanubrutinib were 98.70–101.06% (RSD 5.37–8.49%, n = 6). All values meet US Food and Drug Administration requirements. A rapid, highly selective and sensitive method for the determination of zanubrutinib concentration in plasma by UPLC–MS/MS was successfully developed. This method is suitable for pharmacokinetic studies in beagle dogs by following oral administration of zanubrutinib.     

Zn的高离化态光谱

用SGV-50型正入射式真空紫外谱仪拍摄了三电极触发火花光源的Zn的高离化光谱。在光谱分析方法研究基础上、对Zn光谱进行了分析。证实了ZnⅢ、ZnⅣ和ZnⅤ的3d~k4s和3d~k4p(k=9,8,7)组态现有光谱的分析结果。通过ZnⅣ3d~84d-3d~84p组态跃迁的分析导出了3d~84d组态的19条能级。     

Programming Super DNA-Enzyme Molecules for On-Demand Enzyme Activity Modulation**

Dynamic interactions of enzymes, including programmable configuration and cycling of enzymes, play important roles in the regulation of cellular metabolism. Here, we constructed a super DNA-enzymes molecule (SDEM) that comprises at least two cascade enzymes and multiple linked DNA strands to control and detect metabolism. We found that the programmable SDEM, which comprises glucose oxidase (GOx) and horseradish peroxidase (HRP), has a 20-fold lower detection limit and a 1.6-fold higher reaction rate than free enzymes. An SDEM can be assembled and disassembled using a hairpin structure and a displacement DNA strand to complete multiple cycles. An entropically driven catalytic assembly (catassembly) enables different SDEMs to switch from an SDEM with GOx and HRP cascades to an SDEM with sarcosine oxidase (SOX) and HRP cascades in over six orders of magnitude less time than without the catassembly to detect different metabolisms (GO and sarcosine) on demand.     

Authentication of Cyathulae Radix and Cyathulae Capitatae Radix based on the strength of the characteristic component achybidensaponin I

Because of the immense difficulty in identifying Cyathulae Capitatae Radix adulteration in Cyathulae Radix, this research aims at fortifying the quality control of Cyathulae Radix and its decoction pieces to guarantee the effectiveness and safety of its clinical use in terms of source material. A method was devised to identify Cyathulae Capitatae Radix adulteration in Cyathulae Radix and its decoction pieces. This research takes achybidensaponin I, that is, the characteristic component of Cyathulae Capitatae Radix, as reference substance and adopts HPLC for detection. The results revealed that, among all samples collected, no trace of achybidensaponin I was found in the 21 batches of Cyathulae Radix, whereas achybidensaponin I was found in all the 14 batches of Cyathulae Capitatae Radix. The research sets 5% as the adulteration limit, that is, 1.45 mg/g Cyathulae Capitatae Radix was detected in 57.14% of the 49 batches of market samples collected and the ratio was 51.02% in the case of 5% adulteration limit. The method is not only precise and reliable but can also be used as a supplement for provisions regarding quality control of Cyathulae Radix and its decoction pieces in Pharmacopoeia of the People's Republic of China, to effectively crack down on Cyathulae Capitatae Radix adulteration in the market.     

In situ synthesis of Bi3+-doped δ-MnO2 cathode to enhance the cycle stability for aqueous zinc-ion batteries

Journal of Solid State Electrochemistry - Bi3+-doped δ-MnO2 materials (BMX, X = 5, 10, 15) with long cycle life were obtained by an in situ electrochemical reaction using...