Heating K(4)Mo(2)Cl(8) and 2 equiv of Li[RC(NDipp)(2)](R = H, Ph; Dipp = 2,6-i-Pr(2)C(6)H(3)) in tetrahydrofuran (THF) at 60 degrees C gives two paddlewheel type quadruply bonded dimolybdenum complexes, Mo(2)(mu-Cl)[Cl(2)Li(OEt(2))][mu-eta(2)-RC(N-2,6-i-Pr(2)C(6)H(3))(2)](2)(R = H (1), Ph (2)). The Mo-Mo bond lengths of 1 and 2 are 2.0875(4) and 2.0756(8) A, respectively, indicating typical Mo-Mo quadruple bonds. Reduction of 1 and 2 by two electrons results in the isolation of their corresponding Mo-Mo quintuple bonded complexes, Mo(2)[mu-eta(2)-RC(N-2,6-i-Pr(2)C(6)H(3))(2)](2)(R = H (3), Ph (4)), and the Mo-Mo bond lengths dramatically decrease to 2.0187(9) A (3) and 2.0157(4) A (4), a consequence of the formation of the second delta bond and representing the shortest metal-metal bonds beyond the first row elements. The Mo-Mo quintuple bonding characters are corroborated by DFT calculations at the level of BP86/def2-TZVP and BP86/def2-TZVPP.

OBJECTIVE: To investigate the mechanism of increase of serum bilirubin after hepatic ischemia-reperfusion. METHODS: 104 SD rats were randomly divided into 2 groups: Group A (sham operation group) and Group B (undergoing 70% hepatic 35 min ischemia-reperfusion). Then the rats were subdivided into subgroups according the different time points (1 and 6 hours, and 1, 3, 5 days after reperfusion). Bile of the ischemic hepatic lobes and blood from the vena cava were collected to examine the conjugated bilirubin (CB) in the bile and serum, and total bilirubin (TB) and alanine aminotransferase (ALT) in serum, and the bile generation rate was calculated. Tissues of the left liver lobe were collected to undergo microscopy with hematoxilin and eosin staining. Real time fluorescence PCR was used to analyze the mRNA expression of multi-drug resistance-associated protein 2 (MRP2) and radixin, a cytoskeleton crossslinker protein. Laser confocal method was used to analyze the localization of MRP2 and radixin in canalicular membrane. RESULTS: Pathological examination showed that there was only a mild inflammation in the liver tissues that had undergone ischemia-reperfusion, and no necrosis of hepatocytes was seen. 1 h approximately 3 d after reperfusion, the bile generation rate and CB level in bile were significant decreased, and the serum TB and CB levels were significantly increased 1 h approximately 5 d after reperfusion. Radixin expression was significantly reduced 6 h approximately 1 d after reperfusion, but down-regulation of MRP2 only occurred 6 h after reperfusion. Localization of MRP2 in the canalicular membrane was absent when the expression of radixin was missing. CONCLUSION: Absence of MRP2 localization in canalicular membrane resulted from missing of radixin expression may be the mechanism of an increase of serum bilirubin after hepatic ischemia-reperfusion.

AIM: To prepare hybridoma cell lines were obtained by fusing Sp2/0 with spleen cells from BALB/c mice immunized with killed enterohemorrhagic E.coli O157:H7 EspA (EHEC O157:H7 EspA). METHODS: The subclass isotype and the specificity of monoclonal antibodies (mAb) were determined and identified by ELISA, Western blot and immune fluorescence staining. RESULTS: Isotype of 3 mAb was IgG1kappa, IgG1lambda, and IgG2kappa, respectively, and the affinity constant were 3.0x10(9), 2.8x10(9), 1.9x10(9). As demonstrated by Western blot, these 3 mAb specifically reacted with EspA protein and EHEC O157:H7. Useing immune fluorescence staining, EHEC O157:H7 could adhere to the membrace of Hela cell. CONCLUSION: Three hybridoma cell lines can stably secrete anti-EspA mAb with high-titer and high-specific have been established. It can be used to deeply study EHEC O157:H7 pathopoiesis mechanism.

The components concentrations in maize stover were analyzed with 67 samples selected from 380 samples of different provinces and varieties in order to serve the biomass utilization of our country. The technique of near infrared reflectance spectroscopy (NIRS) and partial least square (PLS) regression were used to establish the models. The results showed that the calibration models developed by the spectral data pretreatment of the first derivative+Karl Norris derivative filter were the best for ash, hemicellulose, cellulose, Klason lignin, acid unsolvable ash, and water in the spectral region of 4100-7500 cm(-1). The root mean square error of cross validation (RMSECV) for the above six components was 0.991, 1.27, 1.44, 0.599, 0.0903 and 0.547, respectively; the root mean square error of prediction (RMSEP) was 0.7746%, 1.8072%, 0.2569%, 2.5819%, 0.5158% and 1.0325%, respectively. The models can be used to measure various samples in biomass transformation industry.

OBJECTIVE: To observe induction of heat shock reaction by pretreatment of Doxorubicin (DXR) in long-term cold preservation-reperfusion injury of the rat liver. METHODS: The rats were administered intravenously by DXR at a dose of 1 mg/kg body weight in DXR group and by saline in control group. After 48 hours, the rat liver was perfused by using cold University of Wisconsin (UW) solutions and was preserved in UW solution at 4 degrees C for 48 hours. Recipient liver was perfused for 1 and 3 hours after orthotopic liver transplantation. Tumor necrosis factor-alpha (TNF-alpha) mRNA, cytokine-induced neutrophil chemoattractant (CINC) mRNA, macrophage inflammatory protein (MIP-2) mRNA was measured by RT-PCR and heat shock protein 72 (HSP72), nuclear factor-kappaB (NF-kappaB) by Western blot. The serum levels of TNF-alpha, CINC, MIP-2 by ELISA and AST were measured. The survival rate of 7 days was observed. RESULTS: The expression of TNF-alpha mRNA, CINC mRNA and MIP-2 mRNA was stronger in control group than in DXR group. HSP72 was expressed in SA group but not in control group and oppositely NF-kappaB was expressed in control group but not in DXR group. Serum AST, TNF-alpha, CINC and MIP-2 concentrations were significantly lower in DXR group than in control group (P < 0.05). The survival rate of 7 days was significantly higher in DXR group than in control group (50% vs. 0%, P < 0.05). CONCLUSIONS: These data suggested that long-term cold ischemia-reperfusion injury was attenuated in liver graft with pretreatment of DXR. The induction of HSP72 may offer protection to hepatocytes by restraining the activation of NF-kappaB and inflammation.

We studied the alteration of the maize straw apoplast proteins in the process of preservation, and analyzed the effects of apoplast proteins on Penicillum expansum cellulase activities. The results show that: the extractable apoplast proteins are gradually decreased during the preservation of maize straw. Meanwhile, their synergistic effects on P. expensum cellulose are also attenuated. The apoplast proteins extracted from fresh maize straw possess endogenous EG activities, which is unstable and completely vanished after 6 months preservation. The apoplast proteins from the preserved straw exhibit significant synergistic effect on FPA, cotton lyase and beta-glucosidase. The maximal synergistic values are 95.32%, 102.06% and 96.6%, respectively. But interestingly, they inhibit the CMCase activity (max. 49.52%). Apoplast proteins show distinctive synergy with betaG and EG, but have no effect on CBH activity. After eliminating the effect of endogenous EG, the apoplast proteins from fresh maize straw have enhanced synergistic or inhibiting effects on FPA, Cotton lyase, betaG and CMCase than those extracted from the preserved straw. Based on our observation, the apoplast proteins play important roles in regulating the cellulase activities. The detailed analysis of the related mechanisms will greatly benefit the studies of the natural biomaterials hydrolysis.

An ultrafiltration membrane bioreactor consisted of 1 - 6 enzymatic vessel was used to increase the reducing sugar concentration. The effects of enzyme loading, the number of enzymatic vessel and the dilution rate on enzymatic hydrolysis of steam-exploded rice straw were studied. The results show that the best condition is: 20FPU/g, four enzymatic vessels and 0.075/h (D). Compared with traditional batch reaction, the conversion of substrate increased significantly from 18%- 21% to 39.5%. Compared with the ultrafiltration membrane bioreactor consisted of one enzymatic vessel, the production of reducing sugar increased from 0.25 g/ g to 0.4g/g, and the final reducing sugar concentration in the product stream increased from 4.56g/L to 27.23g/L.

AIM: To describe the significant over-expression of fibroblast growth factor receptor 3 (FGFR3), which is a signal transduction and cell proliferation related gene in hepatocellular carcinoma (HCC). METHODS: Following DNA microarray, Northern blot and quantitative real-time PCR were employed to confirm FGFR3 expression difference in HCC tissues and surrounding non-neoplastic liver tissue. FGFR3 expression levels were further determined by immunohistochemical study in 43 cases of HCC. RESULTS: Northern blot results showed the significant over-expression of FGFR3 in HCC tissues, which was consistent with that from DNA microarray. Quantitative real-time PCR demonstrated that the mean ratio of FGFR3 mRNA to glyceraldehyde-3-phosphate dehydrogenase (GADPH) mRNA in HCC tissue was 0.250, whereas the ratio in non-neoplastic liver tissue was 0.014. Statistical analyses of 43 cases of HCC revealed that HCC scored higher than the matched non-neoplastic liver tissues. Examination of clinicopathological features revealed a strong correlation of over-expression of FGFR3 with poor tumor differentiation and high nuclear grade. CONCLUSION: Over-expression of FGFR3 may play an important role in liver carcinogenesis. FGFR3 may be an ideal candidate as a molecular marker in the diagnosis of HCC and a potential therapeutic target.

The periodic change of environment factors in air pressure oscillation solid state fermentation bioreactor was studied. Based this research the effect of the periodic environment stimulations on Penicillium decumbens JUA10 cultured in solid state substrate was researched too. The research results showed that in this bioreactor air temperature and relative humidity had large amplitude periodic change drived by air pressure oscillation. The changes had same frequency with the air pressure Oscillation and had amplitude that increased with the air pressure increased. When the press lower limit and upper limit were 0.0MPa and 0.2MPa respectively, pulsating period was 20 min, contrast to the period gather breath solid state fermentation, the air press pulsating SSF had a 2.29 times total CO2 production increase, 3.2 times enzyme activity increase and 1.04 times biomass increase. The data suggested air press pulsating stimulation not only increased biomass but also the metabolic activity.

The objective of the study was to characterize and map changes in lignin during hydrothermal and wet explosion pre-treatments of wheat straw and corn stover. Chemical composition, microscopic (atomic force microscopy and scanning electron microscopy) and spectroscopic (attenuated total reflectance Fourier transform infrared spectroscopy, ATR-FTIR) analyses were performed. Results showed that both pre-treatments improved the cellulose and lignin content with substantial removal of hemicellulose in the pre-treated biomasses. These values were slightly higher for hydrothermal compared to wet explosion pre-treatment. ATR-FTIR analyses also confirmed these results. Microscopic analysis showed that pre-treatments affected the biomass by partial difibration. Lignin deposition on the surface of the hydrothermally pre-treated fibre was very distinct while severe loss of fibril integrity was noticed with wet exploded fibre. The present study thus revealed that the lignin cannot be removed by the studied pre-treatments. However, both pre-treatments improved the accessibility of the biomass towards enzymatic hydrolysis.

The fixation mechanism of CuAz preservatives in bamboo was studied with bamboo as the experimental material in the present paper. The purpose of the study is to understand the interaction between preservatives and bamboo, provide a theoretical basis for the design and optimization of preservatives formula and for improving preservative treatment. The chemical combination between preservatives and bamboo components was analysed by ATR Fourier transform infrared spectroscopy (ATR-FTIR), and the results show that the infrared spectra of lignin after treatment changed significantly. The lignin characteristic peaks (1,510 cm(-1)) changed obviously. Lignin phenolic hydroxyl was involved in the lignin-copper complex formation. Holocellulose's spectra after treatment changed little, with just a change in hemicellulose carboxyl and hemicellulose acyl-oxygen bond (CO-O) stretching vibration.

Bsi20310 exopolysaccharide (Bsi20310 EPS) was secreted by a bacteria named Pseudoalteromonas sp. Bsi20310, isolated from Antarctic Sea ice. Crude Bsi20310 EPS was prepared by precipitation of the culture solution with ethanol, with proteins removed by using chloroform and butanol preparatorily. The results showed that Bsi20310 EPS improved the FeCl3 coagulation performance on synthetic water-soluble dye reactive red X-3B dyeing wastewater, obviously. The optimum coagulation enhancement of Bsi20310 EPS expressed by decolorization rate is from 16% to 84%, at pH near 10, Fe(III) concentration of 0. 98 mmol x L(-1) and Bsi20310 EPS concentration of 150 mg x L(-1), respectively. Fourier transform infrared spectroscopy (FTIR) was used to investigate the functional groups of Bsi20310 EPS, Fe(III)-Bsi20310 EPS floc and Fe(III)-Bsi20310 EPS-reactive red X-3B floc. The spectra showed that Bsi20310 EPS contained a large number of functional groups such as -OH,-COOH and glycosidic bond. Some certain functional groups of Bsi20310 EPS changed being combined with Fe(III) hydrolysate. For instance, narrow peaks at 3429 and 1650 cm(-1) became wide; the peak at 2 921 cm(-1) weakened or disappeared; the peak at 1242 cm(-1) red-shifted slightly; peaks in the region of 1151-1038 cm(-1) became single and sharp, etc. The change in spectra indicated that -OH,-OOH and glycosidic bond might be the main functional groups. The study suggested a bright prospect of Bsi20310 EPS performing as an approach to safe and effective microbial coagulation enhancement.

On the basis of available data with regard to the chemical and physical properties of the "substrate" luciferin (LH(2)) and enzyme, luciferase (A), and of kinetic data derived both from the reaction in extracts of Cypridina, and from the luminescence of intact bacteria, the fundamental reactions involved in the phenomenon of bioluminescence have been schematized. These reactions provide a satisfactory basis for interpreting the known characteristics of the system, as well as the theoretical chemistry with regard to the control of its over-all velocity in relation to various factors. These factors, here studied experimentally wholly with bacteria, Photobacterium phosphoreum in particular, include pH, temperature, pressure, and the drugs sulfanilamide, urethane, and alcohol, separately and in relation to each other. Under steady state conditions of bacterial luminescence, with excess of oxidizable substrate and with oxygen not limiting, the data indicate that the chief effects of these agents center around the pace setting reactions, which may be designated by the equation: A + LH(2)--> ALH(2) following which light emission is assumed proportional to the amount of the excited molecule, AL*. The relation between pH and luminescence intensity varies with (a), the buffer mixture and concentration,(b), the temperature, and (c), the hydrostatic pressure. At an optimum temperature for luminescence of about 22 degrees C. in P. phosphoreum, the effects of increasing or decreasing the hydrogen ion concentration are largely reversible over the range between pH 3.6 and pH 8.8. The relation between luminescence intensity and pH, under the experimental conditions employed, is given by the following equation, in which I(1) represents the maximum intensity, occurring about pH 6.5; I(2) the intensity at any other given pH; K(5) the equilibrium constant between hydrogen ions and the AL(-); and K(6) the corresponding constant with respect to hydroxyl ions: See PDF for Equation The value of K(5), as indicated by the data, amounts to 4.84 x 10(4), while that of K(6) amounts to 4.8 x 10(5). Beyond the range between approximately pH 3.8 and 8.8, destructive effects of the hydrogen and hydroxyl ions, respectively, were increasingly apparent. By raising the temperature above the optimum, the destructive effects were apparent at all pH, and the intensity of the luminescence diminished logarithmically with time. With respect to pH, the rate of destruction of the light-emitting system at temperatures above the optimum was slowest between pH 6.5 and 7.0, and increased rapidly with more acid or more alkaline reactions of the medium. The reversible effects of slightly acid pH vary with the temperature in the manner of an inhibitor (Type I) that acts independently of the normal, reversible denaturation equilibrium (K(1)) of the enzyme. The per cent inhibition caused by a given acid pH in relation to the luminescence intensity at optimum pH, is much greater at low temperatures, and decreases as the temperature is raised towards the optimum temperature. The observed maximum intensity of luminescence is thus shifted to slightly higher temperatures by increase in (H(+)). The apparent activation energy of luminescence is increased by a decrease in pH. The value of DeltaHdouble dagger at pH 5.05 was calculated to be 40,900 calories, in comparison with 20,700 at a pH of 6.92. The difference of 20,200 is taken to represent an estimate of the heat of ionization of ALH in the activation process, and compares roughtly with the 14,000 calories estimated for the same process, by analyzing the data from the point of view of hydrogen ions as an inhibitor. The decreasing temperature coefficient for luminescence in proceeding from low temperatures towards the optimum is accounted for in part by the greater degree of ionization of ALH. At the optimum temperature and acid reactions, pressures up to about 500 atmospheres retard the velocity of the luminescent oxidation. At the same temperature, with decrease in hydrogen ion concentration, the pressure effect is much less, indicating a considerable volume increase in the process of ionization and activation. In the extremely alkaline range, beyond pH 9, luminescence is greatly reduced, as compared with the intensity at neutrality, and under these conditions pressure causes a pronounced increase in intensity, presumably by acting upon the reversible denaturation equilibrium of the protein enzyme, A. Sulfanilamide, in neutral solutions, acts on luminescence in a manner very much resembling that of hydrogen ions at acidities between pH 4.0 and pH 6.5. Like the hydrogen ion equilibrium, the sulfanilamide equilibrium involves a ratio of approximately one inhibitor molecule to one enzyme molecule. The heat of reaction amounts to about 11,600 calories or more in a reversible combination that evidently evolves heat. Like the action of H ions, sulfanilamide causes a slight shifting of maximum luminescence intensity in the direction of higher temperatures, and an increase in the energy of activation. The effect of sulfanilamide on the growth of broth cultures of eight species of luminous bacteria indicates that there is no regular relationship among the different organisms between the concentration of the drug that prevents growth, and that which prevents luminescence in the cells which develop in the presence of sulfanilamide. p-Aminobenzoic acid (PAB) antagonizes the sulfanilamide inhibition of growth in luminous bacteria, and the cultures that develop are luminous. When (PAB) is added to cells from fully developed cultures, it has no effect on luminescence, or causes a slight inhibition, depending on the concentration. With luminescence partly inhibited by sulfanilamide, the addition of PAB has no effect, or has an inhibitory effect which adds to that caused by sulfanilamide. Two different, though possibly related, enzyme systems thus appear to limit growth and luminescence, respectively. The possible mechanism through which both the inhibitions and the antagonism take place is discussed. The irreversible destruction of the luminescent system at temperatures above that of the maximum luminescence, in a medium of favorable pH to which no inhibitors have been added, proceeds logarithmically with time at both normal and increased hydrostatic pressures. Pressure retards the rate of the destruction, and the analysis of the data indicates that a volume increase of roughly 71 cc. per gm. molecule at 32 degrees C. takes place in going from the normal to the activated state in this reaction. At normal pressure, the rate of destruction has a temperature coefficient of approximately 90,000 calories, or about 20,000 calories more than the heat of reaction in the reversible denaturation equilibrium. The data indicate that the equilibrium and the rate process are two distinct reactions. The equation for luminescence intensity, taking into account both the reversible and irreversible phases of the reaction is given below. In the equation b is a proportionality constant; k' the rate constant of the luminescent reaction; A(0) the total luciferase; A(0i) the total initial luciferase at time t equals 0; k(n) the rate constant for the destruction of the native, active form of the enzyme; k(d) the rate constant for the destruction of the reversibly denatured, inactive form; t the time; and the other symbols are as indicated above: See PDF for Equation For reasons cited in the text, k(n) evidently equals k(d). Urethane and alcohol, respectively, act in a manner (Type II) that promotes the breaking of the type of bonds broken in both the reversible and irreversible reactions and so promotes the irreversible denaturation. This result is in contrast to the effects of sulfanilamide, which at appropriate concentrations may give rise to the same initial inhibition as that caused by urethane, but remains constant with time. The inhibition caused by urethane and alcohol, respectively, increases as the temperature is raised. As a result, the apparent optimum is shifted to lower temperatures, and the activation energy for the over-all process of luminescence diminishes. An analysis for the approximate heat of reaction in the equilibrium between these drugs and the enzyme, indicates 65,000 calories for urethane, and 37,000 for alcohol. A similar analysis with respect to the effect of hydroxyl ions as the inhibitor gives 60,300 calories. The effects of alcohol and urethane are sensitive to hydrostatic pressure. Moderate inhibitions at optimum temperature and pH, caused by relatively small concentrations of either drug, are completely abolished by pressures of 3,000 to 4,000 pounds per square inch. At optimum temperature and pH, increasing concentrations of alcohol caused the apparent optimum pressure for luminescence to shift markedly in the direction of higher pressures. Analysis of the data with respect to concentration of alcohol at different pressures indicated that the ratio of alcohol to enzyme molecules amounted to approximately 4, at 7,000 pounds, but only about 2.8 at normal pressures. This phenomenon was taken to indicate that more than one equilibrium is established between the alcohol and the protein. A similar interpretation was suggested in connection with the fact that analysis of the relation between concentration of urethane and amount of inhibition at different temperatures also indicated a ratio of urethane to enzyme molecules that increased with temperature in the equilibria involved. Analysis of the data with respect to pressure and the inhibition caused by a given concentration of alcohol at different temperatures indicated that the volume change involved in the combination of alcohol with the enzyme must be very small, while the actual effect of pressure is apparently mediated through the reversible denaturation of the protein enzyme, which is promoted by alcohol, urethane, and drugs of similar type.

1. It has been shown in this paper that while non-ionized gelatin may exist in gelatin solutions on both sides of the isoelectric point (which lies for gelatin at a hydrogen ion concentration of C(H)= 2.10(-5) or pH = 4.7), gelatin, when it ionizes, can only exist as an anion on the less acid side of its isoelectric point (pH > 4.7), as a cation only on the more acid side of its isoelectric point (pH < 4.7). At the isoelectric point gelatin can dissociate practically neither as anion nor as cation. 2. When gelatin has been transformed into sodium gelatinate by treating it for some time with M/32 NaOH, and when it is subsequently treated with HCl, the gelatin shows on the more acid side of the isoelectric point effects of the acid treatment only; while the effects of the alkali treatment disappear completely, showing that the negative gelatin ions formed by the previous treatment with alkali can no longer exist in a solution with a pH < 4.7. When gelatin is first treated with acid and afterwards with alkali on the alkaline side of the isoelectric point only the effects of the alkali treatment are noticeable. 3. On the acid side of the isoelectric point amphoteric electrolytes can only combine with the anions of neutral salts, on the less acid side of their isoelectric point only with cations; and at the isoelectric point neither with the anion nor cation of a neutral salt. This harmonizes with the statement made in the first paragraph, and the experimental results on the effect of neutral salts on gelatin published in the writer's previous papers. 4. The reason for this influence of the hydrogen ion concentration on the stability of the two forms of ionization possible for an amphoteric electrolyte is at present unknown. We might think of the possibility of changes in the configuration or constitution of the gelatin molecule whereby ionized gelatin can exist only as an anion on the alkaline side and as a cation on the acid side of its isoelectric point. 5. The literature of colloid chemistry contains numerous statements which if true would mean that the anions of neutral salts act on gelatin on the alkaline side of the isoelectric point, e.g. the alleged effect of the Hofmeister series of anions on the swelling and osmotic pressure of common gelatin in neutral solutions, and the statement that both ions of a neutral salt influence a protein simultaneously. The writer has shown in previous publications that these statements are contrary to fact and based on erroneous methods of work. Our present paper shows that these claims of colloid chemists are also theoretically impossible. 6. In addition to other physical properties the conductivity of gelatin previously treated with acids has been investigated and plotted, and it was found that this conductivity is a minimum in the region of the isoelectric point, thus confirming the conclusion that gelatin can apparently not exist in ionized condition at that point. The conductivity rises on either side of the isoelectric point, but not symmetrically for reasons given in the paper. It is shown that the curves for osmotic pressure, viscosity, swelling, and alcohol number run parallel to the curve of the conductivity of gelatin when the gelatin has been treated with acid, supporting the view that these physical properties are in this case mainly or exclusively a function of the degree of ionization of the gelatin or gelatin salt formed. It is pointed out, however, that certain constitutional factors, e.g. the valency of the ion in combination with the gelatin, may alter the physical properties of the gelatin (osmotic pressure, etc.) without apparently altering its conductivity. This point is still under investigation and will be further discussed in a following publication. 7. It is shown that the isoelectric point of an amphoteric electrolyte is not only a point where the physical properties of an ampholyte experience a sharp drop and become a minimum, but that it is also a turning point for the mode of chemical reactions of the ampholyte. It may turn out that this chemical influence of the isoelectric point upon life phenomena overshadows its physical influence. 8. These experiments suggest that the theory of amphoteric colloids is in its general features identical with the theory of inorganic hydroxides (e.g. aluminum hydroxide), whose behavior is adequately understood on the basis of the laws of general chemistry.

In the present article, the authors mensurated the infrared spectra of 22 conifer and broadleaf trees such as ginkgo biloba L., cycas revoluta thunb., Populus tomentosa Carr and so on using FTIR, analyzed the difference of a number of absorb peaks in fingerprint area, the characteristic absorb peak position of cellulose and lignin of these trees and their alternation regulations of relative intensity, then discussed the evolutional issue of ginkgo biloba. The results show that ginkgo biloba is different from cycas in the infrared spectra of wood but similar to the conifer trees, which illustrates the ginkgo biloba. is more evolutional than cycas in the timber's chemical composition but with similar affiliation to conifer trees. The content of lignin in the ginkgo biloba wood is more than that in other conifer trees, which may be a original character of ginkgo biloba. Meanwhile, the ginkgo biloba has some syringyl lignins in addition to guaiacyl, and it has the evolutional tendency for broadleaf trees.

The photodegradation process of bamboo involves very complex chemical reactions. In the present study, surface deterioration of Moso bamboo (Phyllostachys pubescens Mazel) was carried out by a xenon fade meter which can simulate sunlight irradiation, and Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopic (XPS) techniques were used to characterize the resulting changes in the chemical structure and composition of bamboo surface. XPS results showed that light irradiation resulted in significant increases in oxygen (O) content and O/C ratio. Besides, changes were also identified from the detailed C(ls) spectra, with a remarkable decrease in C1 component (C-C) and simultaneous increases in the components of C2 (C-O), C3 (C = O) and C4 (O-C = O), suggesting that the carbon atoms at bamboo surface were highly oxidized. FTIR results showed that lignin was susceptible to light irradiation and was significant degraded after treatment, as indicated by remarkable decreases in the intensity of lignin associated bands (e. g. 1 604, 1 512 and 1 462 cm(-1)). This was accompanied by the formation of new carbonyl compounds as shown by an obvious increase in the intensity of non-conjugated carbonyl group at 1 735 cm(-1), which further indicated the photo-oxidation of bamboo surface. The polysaccharides (cellulose and hemicellulose) components, however, were less influenced by light irradiation, and their relative content at bamboo surface increased significantly due to lignin degradation.

An alkalophilic and halotolerant laccase from gamma-proteobacterium JB catalyzed in high concentrations of organic solvents and various salts. The enzyme retained 80-100% activity in 10% concentration of dimethylsulfoxide (DMSO), ethanol, acetone or methanol; 100, 85 and 50% activity in 20 mM MgCl(2), 5.0 mM MnCl(2) and 0.1 mM CuCl(2); 140, 120 and 110% activity in 5.0 mM MnSO(4), 10 mM MgSO(4) and 1mM CaSO(4), respectively. Sodium halides inhibited the enzyme in the order: F(-)> Br(-)> I(-)> Cl(-). In 0.5 M NaCl, pH 6.0, laccase was approximately 60% active. Decolorization of indigo carmine by laccase at pH 9.0 was not inhibited even in the presence of 0.5 M NaCl. Release of chromophoric, reducing and hydrophobic compounds during biobleaching of straw rich-soda pulp by laccase was not inhibited when the enzyme was applied in the presence of 1 M NaCl at pH 8.0. Laccase retained 50% residual activity even when incubated with 5% calcium hypochlorite for 30 min.

In this work we compared the efficiency of a laccase treatment performed on steam-exploded wheat straw pretreated under soft conditions (water impregnation) or harsh conditions (impregnation with diluted acid). The effect of several enzymatic treatment parameters (pH, time of incubation, laccase origin and loading) was analysed. The results obtained indicated that severity conditions applied during steam explosion have an influence on the efficiency of detoxification. A reduction of the toxic effect of phenolic compounds by laccase polymerization of free phenols was demonstrated. Laccase treatment of steam-exploded wheat straw reduced sugar recovery after enzymatic hydrolysis, and it should be better performed after hydrolysis with cellulases. The fermentability of hydrolysates was greatly improved by the laccase treatment in all the samples. Our results demonstrate the action of phenolic compounds as fermentation inhibitors, and the advantages of a laccase treatment to increase the ethanol production from steam-exploded wheat straw.

Milled wood lignin (MWL) and acetic and formic acid lignin (AL and FL) from Miscanthus x giganteus bark were produced, respectively, before and after organosolv fractionations under optimal conditions, in terms of organic and hydrochloric acid concentrations, liquid/wood ratio, and reaction time. In order to study the M. x giganteus native lignin structure and its modifications during the fractionation process, the lignins were studied by two-dimensional heteronuclear single quantum coherence (2D-(HSQC)),(13)C- and (31)P nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared (FTIR), size-exclusion chromatography (SEC) both before and after thioacidolysis, and elemental analysis. In addition, chemical composition analysis was performed on ash, Klason lignin, and carbohydrate content. The analyses demonstrated that M. x giganteus native lignin (MWL) is highly acylated at the C(gamma) of the lignin side chain (46%), possibly with p-coumarate and/or acetate groups. This is newsworthy since several earlier studies showed that acylation at the gamma-carbon commonly occurs in C(3) and CAM grasses, whereas M. x giganteus is a C(4) grass. Furthermore, M. x giganteus showed a low S/G ratio (0.7) and a predominance of beta-O-4' linkages (up to 93% of all linkages). AL and FL lose part of these linkages during organosolv fractionation (up to 21 and 32%, respectively). The p-coumarate groups resist fractionation processes and are still present in high quantities in AL and FL. During the fractionation process, lignin is acetylated (acetic acid process) and condensed, with the G units condensing more than S units. M. x giganteus MWL contains a high content of carbohydrates (22.8%), suggesting that it is a lignin-carbohydrate complex (LCC). AL and FL showed low carbohydrate contents because of the breaking down of the LCC structures. AL and FL have high molecular weights and low polydispersities, and are high in phenolic content, qualities that make these suitable for different applications. These results suggest that refinement of M. x giganteus via organosolv processes could potentially turn this grass into a valuable source of both fiber and lignin.