The evolution of a V-type three-level system is studied, whose two resonances are coherently excited and coupled by two ultrashort laser pump and probe pulses, separated by a varying time delay. We relate the quantum dynamics of the excited multilevel system to the absorption spectrum of the transmitted probe pulse. In particular, by analyzing the quantum evolution of the system, we interpret how atomic phases are differently encoded in the time-delay-dependent spectral absorption profiles when the pump pulse either precedes or follows the probe pulse. This scheme is experimentally applied to atomic Rb, whose fine-structure-split 5s  (2)S{1/2}→5p(2)P{1/2} and 5s(2)S_{1/2}→5p(2)P{3/2} transitions are driven by the combined action of a pump pulse of variable intensity and a delayed probe pulse. The provided understanding of the relationship between quantum phases and absorption spectra represents an important step towards full time-dependent phase reconstruction (quantum holography) of bound-state wave packets in strong-field light-matter interactions with atoms, molecules, and solids.

Abstract. The present study determined the ability of the Lactobacillus rhamnosus GG strain (LGG) to enhance the anticancer effects of geniposide on HSC-3 human oral squamous carcinoma cells.LGG (1.0x10 3 CFU/ml) on its own had no impact on human oral keratinocytes and HSC-3 cancer cells. Geniposide (25 or 50 µg/ml) had no impact on human oral keratinocytes, but exerted growth inhibitory effects on HSC-3 cancer cells, which were increased in the presence of LGG. Flow cytometric analysis and a nuclear staining assay with DAPI revealed that HSC-3 cancer cells treated with LGG-geniposide (1.0x10 3 CFU/ml LGG and 50 µg/ml geniposide) had a higher apoptotic rate than cells in other treatment groups, particularly that treated with geniposide (50 µg/ml) only. Geniposide also increased the mRNA and protein expression of caspase-3, -8 and -9 as well as B-cell lymphoma 2 (Bcl-2)-associated X protein, p53, p21, inhibitor of nuclear factor-κB (NF-κB) α, Fas and Fas ligand, while decreasing Bcl-2, Bcl extra large protein, inhibitor of apoptosis-1 and -2, NF-κB, cyclooxigenase-2 and inducible nitric oxide synthase in HSC-3 cells, which was increased in the presence of LGG. These results indicated that LGG enhanced the anticancer effects of geniposide in HSC-3 cells. IntroductionGardenia jasminoides Ellis belongs to the Rubiaceae family and Gardenia genus, and its dried ripe fruit can be used as a medicine, with bitter and cold taste, and nourishing the heart, lungs and San Juao meridian according to the principles of Chinese Medicine (1). Gardenia fruit mainly protects the liver and nourishes the gallbladder, and its active constituent is geniposide, which belongs to the iridoid glycosides (2). It is also rich in other constituents such as organic acids, pigments and volatile oils (3). A pharmacokinetic study has found that geniposide, the active constituent of Gardenia jasminoides Ellis, is hydrolyzed by β-glucosidase produced by intestinal microorganisms to generate genipin (4). Studies have proved that genipin also significantly reduces inflammation, lipid peroxidation and angiogenesis, with low cytotoxicity, sound biocompatibility and high anti-degradation ability (5,6). Gardenia jasminoides Ellis has a low genipin content, which only accounts for 0.005-0.01%, and mainly exists in the form of its precursor-geniposide, accounting for 3-5%. At present, geniposide is extracted with organic solvents, and 100 g gardenia fruit provide ~4 g geniposide. Therefore, it is of great significance to ferment Gardenia by microorganisms to produce genipin (7). In addition, the use of microorganisms and geniposide may achieve a better control of the concentration of active constituents, which may enhance the pharmacological effect. The transformation of geniposide contained in Gardenia jasminoides by fermentation with microorganisms is carried out by β-glucosidase produced by bacteria, which breaks chemical bonds in geniposide to produce genipin (8).In the present study, high-yield lactobacillus produced by β-glucosidase was used to react...

Controlling chemical reactions by light, i.e., the selective making and breaking of chemical bonds in a desired way with strong-field lasers, is a long-held dream in science. An essential step toward achieving this goal is to understand the interactions of atomic and molecular systems with intense laser light. The main focus of experiments that were performed thus far was on quantum-state population changes. Phase-shaped laser pulses were used to control the population of final states, also, by making use of quantum interference of different pathways. However, the quantum-mechanical phase of these final states, governing the system's response and thus the subsequent temporal evolution and dynamics of the system, was not systematically analyzed. Here, we demonstrate a generalized phase-control concept for complex systems in the liquid phase. In this scheme, the intensity of a control laser pulse acts as a control knob to manipulate the quantum-mechanical phase evolution of excited states. This control manifests itself in the phase of the molecule's dipole response accessible via its absorption spectrum. As reported here, the shape of a broad molecular absorption band is significantly modified for laser pulse intensities ranging from the weak perturbative to the strongfield regime. This generalized phase-control concept provides a powerful tool to interpret and understand the strong-field dynamics and control of large molecules in external pulsed laser fields. C an we find universal concepts to understand and control the response of atoms and molecules in interactions with strong laser fields? This question is at the heart of a vast number of experiments in time-resolved spectroscopy (1-30). The wide range of light sources spanning the spectral range from the X-ray (e.g., free-electron laser sources, synchrotrons) over the visible (conventional laser systems) to the far-infrared regime and covering the temporal range from nanosecond down to attosecond time scales created a wealth of new physics insight into quantum mechanisms, however mostly of simple systems in the gas phase (1-4). In chemistry, the generation of femtosecond laser pulses enabled the investigation of wave packet dynamics in molecules, as the induced vibrations occur on these time scales. Experiments focusing on, for instance, dissociation reactions, atom transfer, isomerization, or solvation dynamics have led to a deeper understanding of chemical bonds and their breakage dynamics and have opened and established the field of femtochemistry (5, 6). The aim is not only to study the light−matter interaction, but to use the obtained understanding of the processes to control the dynamics in complex molecules and, in the future, even to be able to control chemical reactions (7-10). Shaping the amplitude and phase of femtosecond laser pulses has been used, for example, to control the shape of wavefunctions in atomic systems (11) or to control and optimize the single-photon and multiphoton fluorescence in atoms such as cesium (12) and complex systems, e.g....