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The present study investigates the potential role of dioscin (DIO) in the lipopolysaccharide (LPS)‐induced kidney injury. For this purpose, DIO‐loaded zein nanoparticles (DIO‐ZNPs) were formulated and evaluated for physicochemical parameters. The DIO‐ZNPs exhibited a controlled release of drug compared with that of the free drug suspension. Results showed that the cell viability of NRK‐52E consistently decreased with the increase in LPS from 0.01 µg/ml to 2 µg/ml. When compared with LPS, DIO‐induced NPs showed 1.10‐, 1.32‐, 1.57‐ and 1.92‐fold increase in the cell viability for concentrations of 20 µg/ml, 50 µg/ml, 100 µg/ml and 200 µg/ml, respectively. DIO‐ZNPs exhibited the most remarkable recovery in the cell proliferation compared with free DIO as shown by the cellular morphology analysis. Furthermore, Annexin‐V staining analysis showed that the LPS‐treated cells possess the lowest green fluorescence indicating fewer viable cells, whereas DIO‐ZNPs exhibited the maximum green fluorescence comparable with that of the non‐treated cells indicating maximum cell viability. Furthermore, the results show that DIO‐ZNPs significantly increased the expression of miR‐let‐7i in the epithelial kidney cells, whereas the expression levels of TLR4 were significantly downregulated compared with that of the LPS‐treated cells. In conclusion, miR‐let‐7i could be an interesting therapeutic target and nanoparticle‐based DIO could be a potential candidate in the management of acute kidney injury

We provide an analysis of the pigment composition of reconstituted wild type CP29 complexes. The obtained stoichiometry of 9 +/- 0.6 Chls a and 3 +/- 0.6 Chls b per complex, with some possible heterogeneity in the carotenoid binding, is in agreement with 9 Chls a and 3.5 Chls b revealed by the modeling of low-temperature optical spectra. We find that similar to 50% of Chl b614 is lost during the reconstitution/purification procedure, whereas Chls a are almost fully retained. The excitonic structure and the nature of the low-energy (low-E) state(s) are addressed via simulations (using Redfield theory) of 5 K absorption and fluorescence/ nonresonant hole-burned (NRHB) spectra obtained at different excitation/burning conditions. We show that, depending on laser excitation frequency, reconstituted complexes display two (independent) low-E states (i.e., the A and B traps) with different NRHB and emission spectra. The red-shifted state A near 682.4 nm is assigned to a minor (similar to 10%) subpopulation (sub. II) that most likely originates from an imperfect local folding occurring during protein reconstitution. Its lowest energy state A (localized on Chl a604) is easily burned with lambda(B) = 488.0 nm and has a red-shifted fluorescence origin band near 683.7 nm that is not observed in native (isolated) complexes. Prolonged burning by 488.0 nm light reveals a second low-E trap at 680.2 nm (state B) with a fluorescence origin band at similar to 681 nm, which is also observed when using a direct low-fluence excitation near 650 nm. The latter state is mostly delocalized over the a611, a612, a615 Chl trimer and corresponds to the lowest energy state of the major (similar to 90%) subpopulation (sub. I) that exhibits a lower hole-burning quantum yield. Thus, we suggest that major sub. I correspond to the native folding of CP29, whereas the red shift of the Chl a604 site energy observed in the minor sub. II occurs only in reconstituted complexes.

In the photosynthetic green sulfur bacterium Chlorobaculum tepidum, the baseplate mediates excitation energy transfer from the light-harvesting chlorosome to the Fenna-Matthews-Olson (FMO) complex and subsequently toward the reaction center (RC). Literature data suggest that the baseplate is a 2D lattice of BChl a-CsmA dimers. However, recently, it has been proposed, using 2D electronic spectroscopy (2DES) at 77 K, that at least four excitonically coupled BChl a are in close contact within the baseplate structure [ Dostál , J. ; et al., J. Phys. Chem. Lett. 2014 , 5 , 1743 ]. This finding is tested via hole burning (HB) spectroscopy (5 K). Our results indicate that the four excitonic states identified by 2DES likely correspond to contamination of the baseplate with the FMO antenna and possibly the RC. In contrast, HB reveals a different excitonic structure of the baseplate chromophores, where excitation is transferred to a localized trap state near 818 nm via exciton hopping, which leads to emission near 826 nm.

Estuarine wetlands undergoing rapid succession have high organic carbon accumulation rates due to their high primary productivity. A previous study indicated that organic carbon storage in soil differed among successional stages of the Chongming Dongtan tidal wetland due to differences in soil microbial respiration (SMR) and plant biomass. To investigate the mechanisms underlying the differences in SMR, variability in microbial and physicochemical characteristics of soil from different successional stages was studied. Bacterial community composition varied among the successional stages. Some dominant and site-specific bacteria inhabiting the tidal flat may have influenced SMR and soil carbon storage capability. Uncultured members of the Cytophagales and Pseudomonas genera, which include efficient degraders of complex organic compounds, were found primarily in the high tidal flat where the highest SMR and relatively low soil organic carbon storage were observed. Soil environment factors such as particle size, salinity, and total nitrogen (TN) may have affected microbial community composition, in particular the dominant bacterial species, and hence, SMR. The relatively small particle size, low salinity, and high TN in the high tidal flat provided suitable conditions for chemoorganotrophic bacteria such as Cytophagales and Pseudomonas species, which are specialized in the degradation of organic matter.

This work focuses on the low-temperature (5 K) photochemical (transient) hole-burned (HB) spectra within the P870 absorption band, and their theoretical analysis, for the (M)L214G mutant of the photosynthetic Rhodobacter sphaeroides bacterial reaction center (bRC). To provide insight into system-bath interactions of the bacteriochlorophyll a (BChl a) special pair, i.e., P870, in the mutated bRC, the optical line shape function for the P870 band is calculated numerically. On the basis of the modeling studies, we demonstrate that (M)L214G mutation leads to a heterogeneous population of bRCs with modified (increased) total electron-phonon coupling strength of the special pair BChl a and larger inhomogeneous broadening. Specifically, we show that after mutation in the (M)L214G bRC a large fraction (∼50%) of the bacteriopheophytin (HA) chromophores shifts red and the 800 nm absorption band broadens, while the remaining fraction of HA cofactors retains nearly the same site energy as HA in the wild-type bRC. Modeling using these two subpopulations allowed for fits of the absorption and nonresonant (transient) HB spectra of the mutant bRC in the charge neutral, oxidized, and charge-separated states using the Frenkel exciton Hamiltonian, providing new insight into the mutant's complex electronic structure. Although the average (M)L214G mutant quantum efficiency of P(+)QA(-) state formation seems to be altered in comparison with the wild-type bRC, the average electron transfer time (measured via resonant transient HB spectra within the P870 band) was not affected. Thus, mutation in the vicinity of the electron acceptor (HA) does not tune the charge separation dynamics. Finally, quenching of the (M)L214G mutant excited states by P(+) is addressed by persistent HB spectra burned within the B band in chemically oxidized samples.

The exotic species Spartina alterniflora has recently rapidly expanded in the Chongming Dongtan Nature Reserve. As a result, many technologies to control this organism have been developed. To clarify the effects of S. alterniflora invasion as well as the controlling technologies on the organic carbon reservation capability of the Chongming Dongtan Wetland, variations in soil microbial respiration (SMR) after S. alterniflora invasion and the implementation of different controlling technologies in Chongming Dongtan were analyzed, and their influencing mechanisms were studied by analyzing the soil and plant litter characteristics. The results showed that the SMR of S. alterniflora rhizosphere was 1.87 times ( P = 0.000 Phragmites communis rhizosphere, but that their annual organic matter input was almost identical. These findings implied that the organic carbon reservation capability of the S. alterniflora wetland was lower than that of the native P. communis wetland. S. alterniflora stalks more easily decayed into soil than P. communis stalks due to their lower lignin content and C/N ratio. This resulted in increased soil organic carbon (SOC) and TN content in soil of the S. alterniflora rhizosphere, which likely promoted microbial activities, thereby accelerating SMR and organic carbon output. In addition, three artificial measures for controlling the spread of S. alterniflora were found to generally improve the soil microbial activities, thereby increasing organic carbon output when compared to the control. However, when compared to other measures, the effects of mowing plus tillage and waterlogging (MTW) on soil microbial activities and SMR were relatively low owing to restriction by waterlogging. Overall, MTW was a relatively low carbon method for control of the spread of S. alterniflora .

This study describes new recombinant water-soluble chlorophyll (Chl)-binding proteins (WSCP) from Lepidium virginicum (LvWSCP). This complex binds four Chls (i.e. two dimers of Chls) per protein tetramer. We show that absorption, emission, hole-burned (HB) spectra and the shape of the zero-phonon hole (ZPH) action spectrum are consistent with the presence of uncorrelated excitation energy transfer between two Chl dimers. Thus, there is no need to include slow protein relaxation within the lowest excited state (as suggested in a previous analysis of cauliflower WSCP [Schmitt, F.-J. et al. (2008) J. Phys. Chem. B, 112, 13951; Pieper, J. et al. (2011) J. Phys. Chem. B, 115, 4053]) in order to explain the large shift observed between the maxima of the ZPH action and emission spectra. Experimental evidence is provided which shows that electron exchange between lowest energy Chls and the protein may occur, i.e. electrons can be trapped at low temperature by nearby aromatic amino acids. The latter explains the shape of nonresonant HB spectra (i.e. the absence of antihole), demonstrating that the hole-burning process in LvWSCP is largely photochemical in nature, though a small contribution from nonphotochemical hole burning (in resonant holes) is also observed.

Doppler-free two-photon excitation spectra and the Zeeman effects for the 1021401 and 1011401 bands, whose vibrational excess energies are 3412 and 2492 cm−1, respectively, of the S1 1B2u ← S0 1A1g...

Numerous branch features in the (0,0) A 2Pi-X 2Sigma+ band system of calcium monohydride CaH have been studied by optical Stark spectroscopy. The Stark shifts, Stark splittings, and appearance of electric-field-induced transitions in the high resolution laser-induced fluorescence spectra are analyzed to produce values for the magnitude of the permanent electric dipole moments mid R:micromid R: of 2.94(16) D and 2.372(12) D for the X 2Sigma+(v=0) and A 2Pi(v=0) states, respectively. A comparison with values predicted from a semiempirical electrostatic model and previous ab initio calculations for mid R:micromid R: (X 2Sigma+) is presented. The change in mid R:micromid R: upon excitation from the X 2Sigma+ state to the A 2Pi state is rationalized using a simple molecular orbital description.

The high-resolution laser-induced fluorescence spectrum of a molecular beam sample of calcium monohydride (CaH) in the region of the strongly overlapped (1,0) A2Π – X2Σ+ and (0,0) B2Σ+ – X2Σ+ band systems near 630 nm and the (0,0) A2Π – X2Σ+ band system near 690 nm have been recorded and analyzed. The spectral features exhibit a small splitting that is attributed to proton magnetic hyperfine interaction in the X2Σ+ (v = 0) state. The energy levels of the A2Π(v = 0) vibronic state were modeled using a traditional "effective" Hamiltonian approach, whereas those for the interacting A2Π(v = 1)/B2Σ+(v = 0) vibronic levels were modeled by augmenting the traditional effective Hamiltonian with terms to account for local perturbations. An interpretation of the field-free parameters is presented.Key words: calcium monohydride, molecular beam, fluorescence.

A laser spectrometer based on difference frequency generation (DFG) was deployed for real-time long-term monitoring of HCHO concentrations at an environmental monitoring site located at Deer Park, Texas, in the Greater Houston area. Three HCHO concentration measurements were made during the periods of July 20-31 (period I), August 2-14 (period II), and August 24-September 25 (period III), 2002. In periods I and II, differences in HCHO concentrations are apparent between day and night measurements, with elevated concentrations during daylight hours. Most of the HCHO peak values are less than 20 ppbV except for two intense peaks on August 02 (approximately 25 ppbV) and August 04 (approximately 30 ppbV). The formaldehyde concentration levels in ambient air at the measurement site are produced mainly by the photochemical oxidation of volatile organic compounds (VOCs) caused by intense sunlight during periods I and II. This observation was made based on a comparison with the ozone concentration, solar radiation, temperature, relative humidity, and wind speed data obtained from the Texas Commission on Environmental Quality (TCEQ). During period III, data collected by a time-integrating wet-chemical technique are compared to the data collected by the spectroscopic instrument.

We evaluate low-temperature (low-T) emission spectra of photosystem II core complexes (PSII-cc) previously reported in the literature, which are compared with emission spectra of PSII-cc obtained in this work from spinach and for dissolved PSII crystals from Thermosynechococcus (T.) elongatus. This new spectral dataset is used to interpret data published on membrane PSII (PSII-m) fragments from spinach and Chlamydomonas reinhardtii, as well as PSII-cc from T. vulcanus and intentionally damaged PSII-cc from spinach. This study offers new insight into the assignment of emission spectra reported on PSII-cc from different organisms. Previously reported spectra are also compared with data obtained at different saturation levels of the lowest energy state(s) of spinach and T. elongatus PSII-cc via hole burning in order to provide more insight into emission from bleached and/or photodamaged complexes. We show that typical low-T emission spectra of PSII-cc (with closed RCs), in addition to the 695 nm fluorescence band assigned to the intact CP47 complex (Reppert et al. J Phys Chem B 114:11884–11898, 2010), can be contributed to by several emission bands, depending on sample quality. Possible contributions include (i) a band near 690–691 nm that is largely reversible upon temperature annealing, proving that the band originates from CP47 with a bleached low-energy state near 693 nm (Neupane et al. J Am Chem Soc 132:4214–4229, 2010; Reppert et al. J Phys Chem B 114:11884–11898, 2010); (ii) CP43 emission at 683.3 nm (not at 685 nm, i.e., the F685 band, as reported in the literature) (Dang et al. J Phys Chem B 112:9921–9933, 2008; Reppert et al. J Phys Chem B 112:9934–9947, 2008); (iii) trap emission from destabilized CP47 complexes near 691 nm (FT1) and 685 nm (FT2) (Neupane et al. J Am Chem Soc 132:4214–4229, 2010); and (iv) emission from the RC pigments near 686–687 nm. We suggest that recently reported emission of single PSII-cc complexes from T. elongatus may not represent intact complexes, while those obtained for T. elongatus presented in this work most likely represent intact PSII-cc, since they are nearly indistinguishable from emission spectra obtained for various PSII-m fragments.

The optical Stark effect in the B 2 Δ 5/2 ← X 2 Δ 5/2 (1–0)Q e/f (5/2) and P e/f (7/2) lines of nickel monohydride, 58 NiH, was recorded and analyzed to produce values for the permanent electric dipole moment, μ , of 2.44 ± 0.02 D and 0.36 ± 0.02 D for the X 2 Δ 5/2 and B 2 Δ 5/2 states, respectively. The values are in agreement with the previously determined values [J.A. Gray, S.F. Rice, R.W. Field, J. Chem. Phys. 82 (1985) 4717] and with the experimental error approximately a factor of five smaller. A comparison with theoretical predictions and other first-row transition metal monohydrides is given.

A continuous tungsten carbide (WC) molecular beam is being developed to probe for the existence of a possible permanent electric dipole moment (EDM) of the electron. The flux and divergence of the beam are characterized.

Stark spectra of the [16.5]2-X(1)2 and [16.5]2-X(2)3 transitions of cerium monoxide (CeO) have been obtained at a resolution of approximately 50 MHz. Analysis of the Stark spectra yielded permanent electric dipole moments, mu(el), of 3.119(8), 3.115(7), and 2.119(8) D for the X(1)2, X(2)3, and [16.5]2 states, respectively. The ground X(1)2 state dipole moment is shown to follow the trend shown by other lanthanide oxides. While most ab initio calculations tend to overestimate the ground state dipole moment, the value calculated by using pseudopotentials in which the 4f orbital participates in the chemical bonding (Dolg,M.; Stoll, H.; Preuss, H. THEOCHEM 1991, 231, 243] is in very good agreement with our experimental value.

High resolution optical spectroscopy has been used to study a molecular beam of molybdenum monocarbide (MoC). The Stark effect of the R(e)(0) and Q(fe)(1) branch features of the [18.6] (3)Pi(1)-X (3)Sigma(-)(0,0) band system of (98)MoC were analyzed to determine the permanent electric dipole moments mu(e) of 2.68(2) and 6.07(18) D for the [18.6] (3)Pi(1)(nu=0) and X (3)Sigma(-)(nu=0) states, respectively. The dipole moments are compared with the experimental value for ruthenium monocarbide [T. C. Steimle et al., J. Chem. Phys. 118, 2620 (2003)] and with theoretical predictions. A molecular orbital correlation diagram is used to interpret the observed and predicted trends of ground state mu(e) values for the 4d-metal monocarbides series.

Undisturbed natural wetlands are important carbon sinks due to their low soil respiration. When compared with inland alpine wetlands, estuarine wetlands in densely populated areas are subjected to great pressure associated with environmental pollution. However, the effects of water pollution and eutrophication on soil respiration of estuarine and their mechanism have still not been thoroughly investigated. In this study, two representative zones of a tidal wetland located in the upstream and downstream were investigated to determine the effects of water organic pollution and eutrophication on soil respiration of estuarine wetlands and its mechanism. The results showed that eutrophication, which is a result of there being an excess of nutrients including nitrogen and phosphorus, and organic pollutants in the water near Shang shoal located upstream were higher than in downstream Xia shoal. Due to the absorption and interception function of shoals, there to be more nitrogen, phosphorus and organic matter in Shang shoal soil than in Xia shoal. Abundant nitrogen, phosphorus and organic carbon input to soil of Shang shoal promoted reproduction and growth of some highly heterotrophic metabolic microorganisms such as β-Proteobacteria, γ-Proteobacteria and Acidobacteria which is not conducive to carbon sequestration. These results imply that the performance of pollutant interception and purification function of estuarine wetlands may weaken their carbon sequestration function to some extent.

The Zeeman effect in the ground and low-lying excited electronic states of calcium monohydride CaH has been experimentally investigated using optical Zeeman spectroscopy of the (0,0) band of the B{sup 2}{sigma}{sup +}-X{sup 2}{sigma}{sup +} and the (0,0) band of the A{sup 2}{pi}-X{sup 2}{sigma}{sup +} systems. The observed Zeeman-induced shifts and splittings of numerous branch features recorded near the natural linewidth limit were successfully modeled using a traditional effective Hamiltonian approach to account for the interaction between the (v=0) A{sup 2}{pi} and (v=0) B{sup 2}{sigma}{sup +} states and explicit inclusion of the interaction matrix elements for the heterogeneous perturbations between the (v=1) A{sup 2}{pi} and (v=0) B{sup 2}{sigma}{sup +} states. The determined magnetic g factors for the X{sup 2}{sigma}{sup +}, B{sup 2}{sigma}{sup +}, and A{sup 2}{pi} states are compared with previously assumed values and those predicted by perturbation theory.

The electrochemistry and spectroelectrochemistry of [Cl(2)FeS(2)MS(2)FeCl(2)](n)()(-) clusters (where n = 2 for M = Mo and W and n = 3 for M = V; Ia,Ib, and Ic, respectively) and the dimetal complex [Cl(2)FeS(2)MoS(2)](2)(-) (IIIa) were examined in order to characterize the structures and properties of the one-electron-reduced complexes. A stable reduction product for Ia was observed spectroelectrochemically at -1.05 V, which could be oxidized back to the starting complex. Reduction at more negative potentials caused complete bleaching of the spectrum, and the starting complex could not be obtained by reoxidation. Similar behavior was observed for the tungsten complex, Ib, but the dimetal complex [Cl(2)FeS(2)WS(2)](2)(-) was formed upon reoxidation. Chemical and electrochemical reduction of Ia and Ib both led to the same products (IIa and IIb), but by different mechanisms. Borohydride reduction of Ia and Ib led to the initial formation of the dimetal complex, while the electrochemical reduction of Ia proceeded by way of the formation of [Cl(2)FeS(2)MoS(2)FeCl(2)](3)(-). Spectral changes were observed in the reduction of Ic, but they were not reversible. Resonance Raman spectroscopy of the reduced complexes was carried out in order to characterize the reduction product. Two polarized bands in the sulfur bridging region were observed in the resonance Raman spectra of electrochemically and chemically generated IIa and IIb. The relative intensities of these bands were dependent upon the excitation frequency. Reduction of Ic led to the loss of all resonance Raman bands. Reduction of IIIa gave rise to a complex (IVa) that was spectrally quite similar to IIa. These results, along with the previously reported result that the reduction complex was diamagnetic, indicate that the complex IIa is a dimeric species. The most likely structure consistent with these data is a Mo(2)Fe(2)S(4) cubane structure.

Isotope shifts and hyperfine structure of tungsten were studied in the near UV range. We have used laser induced fluorescence spectroscopy on a pulsed supersonic beam to probe the 5D0 -> 5F1 transition at 384.9 nm, 7S3 -> 7P4 transition at 400.9 nm, and 7S3 -> 7P3 transition at 407.4 nm. Three new magnetic hyperfine constants are reported for 7P3,7P4, and 5F1 states. The isotope shifts of the 384.9 nm transition are presented for the first time, and the isotope shifts of 400.9 nm and 407.4 nm transition are measured with an order of magnitude higher precision compared to the previous measurements. As a result, the nuclear parameters lambda and lambda_{rel} are extracted from the isotope shifts with an improved precision., 15 pages, 8 figures

The sub-Doppler laser induced fluorescence spectra of numerous branch features in the B 2Sigma+ -X 2Sigma+(0,0) band of calcium monodeuteride were recorded field-free and in the presence of a static electric field of up to 7 kV/cm. The field-free spectra were analyzed to produce an improved set of fine structure parameters for the B 2Sigma+(v=0) state. The observed electric field induced splittings and shifts were analyzed to produce permanent electric dipole moments of 2.57(3) and 2.51(3) D for B 2Sigma+(v=0) and X 2Sigma+(v=0) states, respectively. The permanent electric dipole moment for the X 2Sigma+(v=0) state of CaH is estimated to be 2.53(3) D.

A number of low-N lines of the X (6)Sigma(+)

A supersonic molecular beam of iron monohydride, FeH, has been generated using a laser ablation/chemical reaction scheme and probed at near-natural linewidth resolution by optical Stark spectroscopy utilizing laser-induced fluorescence detection. The observed Stark splitting in Q(3.5) and R(3.5) lines of the F4Δ7/2← X4Δ7/2 (1,0) transition were analyzed to determine values for the magnitudes of the permanent electric dipole moments, |μ|, which were found to be 2.63(3) and 1.29(3) D for the X4Δ (υ=0) and F4Δ (υ=1) states, respectively. A comparison with ab initio theoretical predictions is made. The Λ doubling in the low-J levels of the F4Δ7/2(υ=1) state is also modeled.