The abuse of fluoroquinolone antibiotics (FQs) has caused negative impact on ecological environment and public health. However, due to complex matrix interference from environmental samples and low content, developing a sensitive and accurate strategy for detecting residual FQs remains a challenge. Herein, amino-functionalized inverse opal photonic crystals (NH2-IOPCs) were successfully fabricated and employed as novel adsorbents for enrichment of FQs. The outstanding enrichment ability was ascribed to the special structure of IOPCs and the interaction of FQs with NH2 groups, as confirmed by theoretical calculation. Combined with the powerful qualitative and quantitative capabilities of ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS), the proposed detection strategy was established for six FQs. Satisfactory analytical performance was obtained with low detection limits (0.01-0.15 µg L-1), a wide linearity range (0.03-2000 µg L-1) with correlation coefficient (R2) ≥0.9967, and excellent reproducibility with relative standard deviations (RSDs) ≤5.2%. The strategy was successfully applied to detect FQs in the medical wastewater, the lake water and the pharmaceutical wastewater with recoveries ranging from 80.7% to 121.2%, confirming the reliability of the strategy. This work not only provides a feasible strategy for monitoring FQs in environmental samples, but also further indicates the potential of photonic crystal materials as adsorbents.

Over the past 20 years, researchers have used multi-omics techniques to study microbial diversity and metabolic function on tobacco leaves. The unique metabolic function of tobacco microorganisms has attracted extensive attention from researchers, which is an important research field in tobacco industry to improve the intrinsic quality of tobacco leaf with microbial agents. The microorganisms are particularly rich on the surface of tobacco leaf, and their metabolic function is closely related to the change of tobacco leaf chemical composition. Some microorganisms have important metabolic functions, such as: degrading macromolecular and harmful substances in tobacco leaves, and they have different degradation rates and pathways for the substances. At present, many functions of tobacco leaf microorganisms have not been fully verified and analyzed. In the future, more novel culture methods are needed to screen and isolate microorganisms on the surface of tobacco leaves, deeply tap their metabolic potential, explore the application value of microorganisms in the tobacco industry, and further promote the innovation and development of the industry.

We demonstrate a high energy nanosecond (ns) slab Yb:YAG master oscillator power-amplifier (MOPA) laser system with high beam quality, operating at room temperature. The MOPA system consists of a Q-switched Yb:YAG rod oscillator and a four-pass Yb:YAG slab amplifier. The oscillator, utilizing a Yb:YAG rod with medium doping concentration (2.0 at.%), delivers a near-diffraction-limited beam with an energy of 2.4 mJ, a repetition rate of 100 Hz, and a pulse duration of 52 ns. The Yb:YAG slab has a 10:1 large aspect ratio and is side-pumped by five laser diode bars via a microlens array shaping system to homogenize and focus the pump beam. The seed pulse energy is amplified to 49 mJ, achieving a laser gain of 20 times, and the experimental result is in fair agreement with the numerical simulation. The average beam quality factor M-2 is measured to be 1.35. The tabletop area of the laser setup is 0.2 m(2), which indicates this scheme has the potential for an application that needs high compactness.

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A new cembrane-type diterpenoid (1) and 9 known cembranoids (2-10) were isolated from the leaves of Nicotiana tabacum. The structure of the new metabolite was confirmed by extensive analyses of their spectroscopic data, including high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), 1D- and 2D nuclear magnetic resonance (NMR) spectroscopy, and infrared spectroscopy (IR). All of the isolated compounds were tested for their protective effects against oxygen-glucose deprivation (OGD)-induced neurotoxicity in SH-SY5Y cells. The new compound 1 exhibited a moderate protective effect against OGD-induced neurotoxicity at 10 μM.

Preservation of the intact cell morphology of bacteria is recognized as one important cause of bacterial drug resistance, and hence developing new antibacterial agents capable of fighting against bacteria via disrupting their cell envelope is highly desirable. Herein, by adopting a modified Stöber method, we developed a one-step approach to fabricate quaternized silica nanoparticles (NPs) using two commercially available molecules-a long alkyl chain-bearing quaternary ammonium silane compound, dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride (Si-QAC), and tetraethyl orthosilicate (TEOS). Specifically, small spherical quaternized silica NPs with an average size of ∼34 nm could be prepared at a TEOS/Si-QAC molar ratio of 4 : 1 with a very high yield (>90%), and the resultant NPs (termed TS4 NPs) possessed superb colloidal stability (at least 520 d) and good biocompatibility. In addition, we confirmed that the long alkyl chain (C18)-bearing quaternary ammonium group endowed the TS4 NPs with the capacity to efficiently kill negatively charged Gram-positive bacteria via both hydrophobic and electrostatic interactions. Specifically, the TS4 NPs could coat the Staphylococcus aureus (S. aureus) cells via densely binding to the bacterial surface and induce the formation of TS4-S. aureus aggregates to exert their membrane disruption and reactive oxygen species (ROS) production effects, leading to the breakage of intracellular DNA and bacterial death. Besides, we revealed that TS4 could eradicate the mature S. aureus biofilms and inhibit the formation of S. aureus biofilms. The present work proposes a simple one-step method to prepare quaternized silica NPs with excellent bacterial adhesion and aggregation properties, which will find practical applications to fight against infections caused by bacteria and their biofilms.

Objective: The pyrolysis transfer rate of aglycones from 7 kinds of glucosides added to cigarette paper in mainstream and sidestream smoke was studied. Methods: 5-methylfurfuryl alcohol glucoside, menthol glucoside, anisyl alcohol glucoside, leaf alcohol glucoside, phenylethanol glucoside, ethyl vanillin glucoside and vanillin glucoside were applied to the surface of cigarette paper and inject into cigarette according to the 0.01% of the weight of cut tobacco respectively. The transfer rates of aglycones in mainstream smoke and side stream smoke were determined under two kinds of flavoring methods. On this basis, the transfer rules of seven aglycones in mainstream smoke and sidestream smoke were studied when the concentration of 0.001%, 0.010% and 0.050% was applied to cigarette paper. Results: In mainstream smoke, the transfer rates of seven aglycones in cut tobacco were higher than those added to cigarette paper, but the opposite was true in sidestream smoke; 5-methylfurfuryl alcohol had the highest transfer rate of aglycones in mainstream smoke and sidestream smoke, and menthol had the lowest transfer rate, followed by leaf alcohol, anisyl alcohol, phenylethanol, ethyl vanillin and vanillin. Under the condition of 0.001% addition, the transfer rates of seven aglycones in mainstream and side stream smoke were 0.27%~1.24% and 0.42%~1.71% respectively, 0.010% addition were 0.38%~1.87% and 0.54%~2.52% respectively, 0.050% addition were 0.31%~1.56% and 0.47%~2.19% respectively. Conclusion: The transfer rates of seven aglycones in side stream smoke were higher than those in mainstream smoke at three additive gradients, the transfer rates of aglycones in mainstream and side stream smoke showed a trend of first increasing and then decreasing with the increase of addition.

We propose and experimentally demonstrate a novel spectral beam combing (SBC) method based on a single slab laser cavity. By establishing the quasi-three-level oscillator model of Yb:YAG crystal, the output characteristics and gain bandwidth of Yb:YAG crystal are investigated theoretically on the basis of the above theoretical model. In a proof-of-principle experiment, the SBC of seven beamlets in a wide-emission-spectrum Yb:YAG slab is realized with an architecture of 7 beamlets which are generated by seven pairs of mini-mirrors and mini-lens, a transform lens, and a multi-layer dielectric grating. Here, a maximum output power of 241 W is achieved, with a 4.1 horizontal beam quality (HBQ) and the output spectrum range spans from $1029.0~\sim ~1031.5$ nm. To the best of our knowledge, this is the first SBC demonstration of solid-state laser based a single slab.

Nanosecond (ns) pulsed laser with high average power and high pulse repetition rate above 50 kHz is a potential solution for laser cutting, laser welding, laser cleaning and many other industry processing scenarios. Although Nd:YAG is a widely used solid-state gain medium, it is difficult to obtain ns pulsed laser with repetition rate above 50 kHz due to its limited stimulated emission cross section and thermal distortion under high pump intensity. In this paper, a kilowatt-level 100 kHz high repetition rate ns Nd:YAG master oscillator power amplifier (MOPA) laser system is reported, and a general optimization method was used to obtain a 205 W seed laser with a high repetition rate of 100 kHz. After beam shaping elements, the seed laser was amplified to 1008 W by a two-rod Nd:YAG preamplifier and a two-rod Nd:YAG main amplifier. The pulse-to-pulse stability factor of the pulsed laser was 0.961 and the pulse width was measured as 142.8 ns. The beam parameter product in the horizontal axis and vertical axis were measured as BPPx = 2.81 mm∙mrad and BPPy = 2.78 mm∙mrad respectively. This is the first time to obtain a kilowatt-level average power ns pulsed laser with repetition rate above 50 kHz using Nd:YAG, and the compact MOPA system is also suitable for power scaling and other practical use.

A high-efficiency and high-power vertical-cavity surface-emitting laser (VCSEL) side-pumped rod Nd:YAG laser with temperature adaptability are demonstrated. The VCSEL side-pumped laser module is designed and optimized. Five VCSEL arrays are symmetrically located around the laser rod and a large size diffused reflection chamber is designed to ensure a uniform pump distribution. Furthermore, the absorbed pump power distribution of the rod is simulated to verify the uniformity of the pump absorption. Finally, a proof-of-principle experiment is performed in short linear cavity laser with single laser module. A continuous-wave output power of 658 W at 1064 nm is obtained, the corresponding optical-to-optical efficiency is 52.6%, and the power variations are ±0.7% over 400 s and ±3.1% over the temperature range from 16 °C to 26 °C. To the best of our knowledge, this is the highest output power and the highest optical-to-optical efficiency ever reported for VCSEL pumped solid-state lasers. By inserting a telescopic module into the cavity and optimizing the TEM 00 mode volume, the average beam quality is measured to be M 2 = 1.34 under an output power of 102 W. The experimental results reveal that such a high power rod laser module with temperature stability is appropriate for field applications.

Due to their strong bacterial binding and bacterial toxicity, cationic liposomes have been utilized as effective antibacterial materials in many studies. However, few researchers have systematically compared their antibacterial activity with their mammalian cell cytotoxicity or have deeply explored their antibacterial and cytotoxicity mechanisms. Here, we prepared a series of cationic liposomes (termed CLs) using dimethyldioctadecylammonium chloride (DODAC) and lecithin at different molar ratios. CLs have the ability to effectively bind with Gram-positive and Gram-negative bacteria through electrostatic and hydrophobic interactions. Further, the CLs with high molar ratios of DODAC (30 and 40 mol%) can disrupt the bacterial wall/membrane, efficiently inducing the production of reactive oxygen species (ROS). More importantly, we carefully compared the antibacterial activity and the mammalian cell cytotoxicity of various CLs differing in DODAC contents and liposomal concentrations and revealed that, whether they are bacterial or mammalian cells, an increasing DODAC content in CLs can lead to an elevated cytotoxicity level. Further, there exists a critical DODAC contents (>20 mol%) in CLs to endow them with effective antibacterial ability. However, the variation in the DODAC content and liposomal concentration of CLs has different degrees of influence on the antibacterial activity or cytotoxicity. For example, CLs at high DODAC content (i.e., CL0.3 and CL0.4) could effectively kill both types of bacterial cells but only cause negligible toxicity to mammalian cells. We believe that a systematic comparison between the antibacterial activity and the cytotoxicity of CLs with different DODAC contents will provide an important reference for the potential clinical applications of cationic liposomes.

Creating an efficient antimicrobial photodynamic therapy (PDT) method while reducing the difficulty of preparation and operation is much anticipated but challenging. In this research, we facilely developed glycol chitosan (GC)/protoporphyrin IX (PpIX) nano-micelles for effective photodynamic inactivation of Gram-positive bacteria. The mixture of glycol chitosan (GC) and protoporphyrin IX (PpIX) self-assembled into positively charged GC/PpIX nano-micelles through hydrophobic interaction and electrostatic interaction. GC/PpIX nano-micelles significantly improved singlet oxygen generation, and notably enhanced the antibacterial PDT effect toward Gram-positive bacteria in a preincubation-free manner without developing drug resistance. Upon binding to the bacterial cells through electrostatic interaction, GC/PpIX nano-micelles were disassembled, leaving GC on the bacterial surface, inducing bacterial cell aggregation and acting like a glue to coat the bacterial surface and release PpIX into the cells, generating singlet oxygen under light irradiation to impair DNA. Collectively, the easy construction of GC/PpIX nano-micelles offers a modality for effective antibacterial PDT with simple operation and without drug resistance development, benefiting the treatment of Gram-positive bacterial infections in clinic.

A new cembrane-type diterpenoid ( 1 ) and 9 known cembranoids ( 2 - 10 ) were isolated from the leaves of Nicotiana tabacum . The structure of the new metabolite was confirmed by extensive analyses of their spectroscopic data, including high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), 1D- and 2D nuclear magnetic resonance (NMR) spectroscopy, and infrared spectroscopy (IR). All of the isolated compounds were tested for their protective effects against oxygen-glucose deprivation (OGD)-induced neurotoxicity in SH-SY5Y cells. The new compound 1 exhibited a moderate protective effect against OGD-induced neurotoxicity at 10 μM.

针对同层工序数量较多的多品种单件或小批量复杂产品的综合调度问题,以优化产品加工的时间成本和提高设备利用率为目标,提出了考虑层级调度次序的资源协同综合调度算法.算法设计了三级调度策略,首先是优先级调度策略,提高了工序间纵向加工的紧密度;其次是叶节点调度策略,实现了横向工序的并行优化;最后是短用时调度策略,充分利用了设备的空闲时间,提高了设备利用率.利用基于Petri网的生产过程模型进行调度仿真,实验结果表明了算法的有效性和可行性.

Detailed chemical constituents of essential oil from the Pterocephalus hookeri leaves and its antimicrobial activities were investigated in this study. The essential oil, obtained by hydrodistillation, was characterized by gas chromatography-flame ionization detection and gas chromatography-mass spectrometry analyses. Among the 90 identified compounds, hexadecanoic acid (21.27%), phytol (8.03%), furfural (7.08%), oleic acid (5.25%), and phytone (4.56%) were the major components. In the antimicrobial assay, the essential oil showed strong inhibitory activities against Escherichia coli, Candida albicans, and Staphylococcus aureus with minimum inhibitory concentration values of 31.3, 62.5, and 125 µg/mL, respectively. To our knowledge, this is the first report concerning chemical composition and antimicrobial activities of the essential oil from Pterocephalus hookeri.

对多种全固态激光中的光谱合成技术进行了探讨和研究,包括光纤激光、Yb:YAG板条激光和半导体激光.对于光纤激光,探讨了基于单个多层介质膜(MLD)光栅、一对MLD光栅、多个体布拉格光栅三种衍射光学元件的光谱合成技术中色散造成的光束质量退化问题,指出子束光谱线型的二阶矩全宽决定了光束质量的退化量,但所允许的光谱宽度又依赖于具体的技术选择途径.进而比较了三种光谱合成方案的优缺点.对于固体激光,实验演示了基于Yb:YAG晶体的板条激光实现光谱合成的原理可行性.通过设计一个基于MLD光栅的振荡器内的光谱合成装置,实现了7束子激光最高241 W的光谱合成输出,合成后光束质量β因子约4.1,表明大功率Yb:YAG板条激光具有通过光谱合束技术实现功率进一步提升的潜力.对于半导体激光,提出并设计了大模场外腔半导体激光+快轴光谱合成的技术.实验演示了9个1 mm宽LD芯片沿快轴方向的光谱合成,用β因子评价合成后的光束质量,在慢轴方向β≈6.3,在快轴方向β≈1.6,表明快轴光谱合成造成的光束质量退化是完全可控的.

以方酸二甲酯及N-酰基-L-脯氨醛为原料,合成了4种新型方酰胺-N-酰基吡咯烷双功能手性催化剂,利用1 H NMR,13 CNMR,HR-MS,IR对催化剂结构进了表征.将该类催化剂应用于2,4-戊二酮对硝基烯烃的不对称Michael加成反应中,考察了溶剂、温度和催化剂用量对反应的影响,得到的最优反应条件为:甲苯为溶剂,催化剂用量为0.5 mol％,室温下反应.在最优反应条件下,以3a为催化剂,合成了12个具有光学活性的3位取代的2,4-戊二酮,最高产率达到97％,最高ee值达到95％.该催化体系能够适合含有吸电子和供电子基团的各种硝基烯烃的不对称加成.

为了改进糖苷化反应的合成工艺,以D-葡萄糖为原料,合成了溴代四乙酰葡萄糖(Ⅱ),化合物Ⅱ与麦芽酚(Ⅰ)分别经相转移催化和Koenigs-Knorr糖苷化反应合成了麦芽酚-2,3,4,6-四-O-乙酰基-β-D-葡萄糖苷(Ⅲ),化合物Ⅲ脱乙酰基得到目标产物麦芽酚-β-D-葡萄糖苷(Ⅳ).产物结构经1HNMR、13CNMR、IR、HRMS确证.考察了糖苷Ⅳ的热裂解和加香评吸效果.结果表明,对于糖苷化反应,相转移催化法优于Koenigs-Knorr法.相转移催化法的反应条件为:丙酮为溶剂,无水K2CO3为缚酸剂,四丁基溴化铵(TBAB)为相转移催化剂,n(麦芽酚):n(溴代四乙酰葡萄糖)=1.0:1.2,室温反应4 h,化合物Ⅲ的产率为75.6％.化合物Ⅲ在甲醇钠/甲醇体系进行水解得到化合物Ⅳ.糖苷Ⅳ受热裂解能释放出麦芽酚等特征香味成分,将其添加于卷烟中能够改善香气品质.

A new pterocarpan, named davidicarpan A (1), together with 9 known flavonoids, including 3 pterocarpans (2-4) and 6 isoflavones (5-10), were isolated from the flowers of Sophora davidii (France.) Pavol. Their structures were confirmed by high-resolution electrospray ionization-mass spectrometry, one-dimensional (1D) and 2D nuclear magnetic resonance spectroscopy, and comparison with reported literature values. Compounds 1 and 4 exhibited anti-tobacco mosaic virus (anti-TMV) activities with inhibition rates of 27.4% and 26.2%, which was higher than that of the positive control, ningnamycin.