Synergistic Catalytic Removal of NOx and n-Butylamine via Spatially Separated Cooperative Sites.

Synergistic control of nitrogen oxides (NOx) and nitrogen-containing volatile organic compounds (NVOCs) from industrial furnaces is necessary. Generally, the elimination of n-butylamine (n-B), a typical pollutant of NVOCs, requires a catalyst with sufficient redox ability. This process induces the production of nitrogen-containing byproducts (NO, NO2, N2O), leading to lower N2 selectivity of NH3 selective catalytic reduction of NOx (NH3-SCR). Here, synergistic catalytic removal of NOx and n-B via spatially separated cooperative sites was originally demonstrated. Specifically, titania nanotubes supported CuOx-CeO2 (CuCe-TiO2 NTs) catalysts with spatially separated cooperative sites were creatively developed, which showed a broader active temperature window from 180 to 340 °C, with over 90% NOx conversion, 85% n-B conversion, and 90% N2 selectivity. A synergistic effect of the Cu and Ce sites was found. The catalytic oxidation of n-B mainly occurred at the Cu sites inside the tube, which ensured the regular occurrence of the NH3-SCR reaction on the outer Ce sites under the matching temperature window. In addition, the n-B oxidation would produce abundant intermediate NH2*, which could act as an extra reductant to promote NH3-SCR. Meanwhile, NH3-SCR could simultaneously remove the possible NOx byproducts of n-B decomposition. This novel strategy of constructing cooperative sites provides a distinct pathway for promoting the synergistic removal of n-B and NOx.

Phosphotungstic Acid as a Dechlorination Agent Collaborates with CeO2 for Synergistic Catalytic Elimination of NOx and Chlorobenzene.

The development of efficient technologies for the synergistic catalytic elimination of NOx and chlorinated volatile organic compounds (CVOCs) remains challenging. Chlorine species from CVOCs are prone to catalyst poisoning, which increases the degradation temperature of CVOCs and fails to balance the selective catalytic reduction of NOx with the NH3 (NH3-SCR) performance. Herein, synergistic catalytic elimination of NOx and chlorobenzene has been originally demonstrated by using phosphotungstic acid (HPW) as a dechlorination agent to collaborate with CeO2. The conversion of chlorobenzene was over 80% at 270 °C, and the NOx conversion and N2 selectivity reached over 95% at 270-420 °C. HPW not only allowed chlorine species to leave as inorganic chlorine but also enhanced the BroÌ·nsted acidity of CeO2. The NH4+ produced in the NH3-SCR process can effectively promote the dechlorination of chlorobenzene at low temperatures. HPW remained structurally stable in the synergistic reaction, resulting in good water resistance and long-term stability. This work provides a cheaper and more environmentally friendly strategy to address chlorine poisoning in the synergistic reaction and offers new guidance for multipollutant control.

Synergistic catalytic removal of NOx and chlorinated organics through the cooperation of different active sites.

The synergistic removal of NOx and chlorinated volatile organic compounds (CVOCs) has become the hot topic in the field of environmental catalysis. However, due to the trade-off effects between catalytic reduction of NOx and catalytic oxidation of CVOCs, it is indispensable to achieve well-matched redox property and acidity. Herein, synergistic catalytic removal of NOx and chlorobenzene (CB, as the model of CVOCs) has been originally demonstrated over a Co-doped SmMn2O5 mullite catalyst. Two kinds of Mn-Mn sites existed in Mn-O-Mn-Mn and Co-O-Mn-Mn sites were constructed, which owned gradient redox ability. It has been demonstrated that the cooperation of different active sites can achieve the balanced redox and acidic property of the SmMn2O5 catalyst. It is interesting that the d band center of Mn-Mn sites in two different sites was decreased by the introduction of Co, which inhibited the nitrate species deposition and significantly improved the N2 selectivity. The Co-O-Mn-Mn sites were beneficial to the oxidation of CB and it cooperates with Mn-O-Mn-Mn to promote the synergistic catalytic performance. This work paves the way for synergistic removal of NOx and CVOCs over cooperative active sites in catalysts.

Selective Synergistic Catalytic Elimination of NOx and CH3SH via Engineering Deep Oxidation Sites against Toxic Byproducts Formation.

NOx and CH3SH as two typical air pollutants widely coexist in various energy and industrial processes; hence, it is urgent to develop highly efficient catalysts to synergistically eliminate NOx and CH3SH. However, the catalytic system for synergistically eliminating NOx and CH3SH is seldom investigated to date. Meanwhile, the deactivation effects of CH3SH on catalysts and the formation mechanism of toxic byproducts emitted from the synergistic catalytic elimination reaction are still vague. Herein, selective synergistic catalytic elimination (SSCE) of NOx and CH3SH via engineering deep oxidation sites over Cu-modified Nb-Fe composite oxides supported on TiO2 catalyst against toxic CO and HCN byproducts formation has been originally demonstrated. Various spectroscopic and microscopic characterizations demonstrate that the sufficient chemisorbed oxygen species induced by the persistent electron transfer from Nb-Fe composite oxides to copper oxides can deeply oxidize HCOOH to CO2 for avoiding highly toxic byproducts formation. This work is of significance in designing superior catalysts employed in more complex working conditions and sheds light on the progress in the SSCE of NOx and sulfur-containing volatile organic compounds.

PtNi alloy nanoparticles grown in situ on nitrogen doped carbon for the efficient oxygen reduction reaction.

Currently, Pt based materials are still the most efficient oxygen reduction reaction (ORR) catalysts. However, their poor stability obstructs the commercial viability of fuel cells. To lower the reaction potential barrier and enhance the stability, we constructed alloy PtNi nanoparticles (NPs) with a Pt-rich surface supported on nitrogen-doped carbon (NC) via a simple one-step solvothermal method using easily accessible reagents. The synthesized PtNi/NC exhibits enhanced mass activity (MA), specific activity (SA), and positive onset potential compared with commercial Pt/C catalysts. Meanwhile, the half-wave potential shifted negatively to only 18 mV after 5000 cycles for PtNi/NC, indicating excellent stability. The enhanced ORR performance can be ascribed to the introduction of Ni into Pt optimizing the adsorption energy of Pt towards oxygen by adjusting the d band center of the Pt atom and stronger interaction between the metal NPs and support. Our work provides a potential synthesis strategy for developing a Pt-based catalyst with a low Pt loading and high ORR performance.

Expediting Toluene Combustion by Harmonizing the Ce-O Strength over Co-Doped CeZr Oxide Catalysts.

Low-temperature catalytic degradation of volatile organic compounds (VOCs) by enhancing the activity of non-precious metal catalysts has always been the focus of attention. The mineralization of aromatic VOCs requires the participation of a large number of oxygen atoms, so the activation of oxygen species is crucial in the degradation reaction. Herein, we originally adjust the Ce-O bond strength in CeZr oxide catalysts by cobalt doping to promote the activation of oxygen species, thus improving the toluene degradation performance while maintaining high stability. Subsequent characterizations and theoretical calculations demonstrate that the weakening of the Ce-O bond strength increases the oxygen vacancy content, promotes the activation of oxygen species, and enhances the redox ability of the catalysts. This strategy also promotes the activation of toluene and accelerates the depletion of intermediate species. This study will contribute a strategy to enhance the activation ability of oxygen species in non-noble metal oxide catalysts, thereby enhancing the degradation performance of VOCs.

Recent Advances in TiO2 -based Photoanodes for Photoelectrochemical Water Splitting.

Photoelectrochemical (PEC) water splitting has attracted great attention in the past several decades as it holds great promise to address global energy and environmental issues by converting solar energy into hydrogen. However, its low solar-to-hydrogen (STH) conversion efficiency remains a bottleneck for practical application. Developing efficient photoelectrocatalysts with high stability and high STH conversion efficiency is one of the key challenges. As a typical n-type semiconductor, titanium dioxide (TiO2 ) exhibits high PEC water splitting performance, especially high chemical and photo stability. But, TiO2 has also disadvantages such as wide band gap and fast electron-hole recombination rate, which seriously hinder its PEC performance. This review focuses on recent development in TiO2 -based photoanodes as well as some key fundamentals. The corresponding mechanisms and key factors for high STH, and controllable synthesis and modification strategies are highlighted in this review. We conclude finally with an outlook providing a critical perspective on future trends on TiO2 -based photoanodes for PEC water splitting.

Virulence adaption to environment promotes the age-dependent nasal colonization of Staphylococcus aureus.

Staphylococcus aureus is an important human commensal bacteria colonizing the human body, especially the nasal cavity. The nasal carriage can be a source of S. aureus bacteremia. However, the bacterial factors contributing to nasal colonization are not completely understood. By analysing S. aureus strains from the nasal cavity of the children, young adults, and seniors, we found that the low activity of the SaeRS two-component system (TCS) is an important determinant for S. aureus to colonize in seniors. The senior group isolates of S. aureus showed a rather distinct sequence type composition as compared with other age group isolates. The senior group isolates showed not only a lower gene carriage of enterotoxins a, c, and q but also lower hemolytic activity against human red blood cells. Of regulators affecting hemolysin production (i.e. agr, saeRS, rot, rsp, and sarS), only the SaeRS TCS showed an age-dependent decrease of activity. The decreased virulence and better colonization ability of the senior group isolates of S. aureus were confirmed in the mouse model. The senior group isolates showed the lowest survival and the best adhesion and colonizing ability. Also, the senior nasal secretions supported S. aureus survival better than the child and young adult nasal secretions. These results indicated that the senior nasal cavity favours colonization of S. aureus with higher adhesion and lower virulence, to which the reduced SaeRS TCS activity contributes. Taken together, our results illustrate an example of bacterial adaptation to the changing host environment.

Virulent Staphylococcus aureus colonizes pediatric nares by resisting killing of human antimicrobial peptides.

BACKGROUND: The nasal carriage of Staphylococcus aureus introduces risks for subsequent infections, the rate of which is particularly high in children. The colonization mechanisms of S. aureus are not fully understood. METHODS: The epidemiological characteristics of nasal colonizing strains from pediatric patients undergoing liver transplantation and healthy pre-school children were analyzed first. Phenotypes, including biofilm formation and hemolytic activity, were tested for all the isolates. Bacterial pathogenicity indicated by a mouse skin abscess model and resistance to antimicrobial peptides (AMPs) was compared between the predominant genotypes from each group. RESULTS: The ST188 clone dominated in healthy children, whereas ST59 was prevalent for the pediatric patients. Although ST22 was the second most abundant genotype in the patient group, it was rarely found in healthy children. Interestingly, the colonizing ST59 and ST22 genotypes were more virulent, as indicated by the increased ability for hemolysis in vitro and severe subcutaneous abscesses in the mouse model, compared with ST188. We observed that the virulent ST59 and ST22 displayed higher resistance to antibiotics compared with ST188. Most of the ST59 and ST22 were methicillin-resistant S. aureus (MRSA), and all of the ST188 strains were methicillin-susceptible (MSSA). Moreover, we observed that the virulent ST59 and ST22 can resist killing by human antimicrobial peptides (AMPs). Mechanically, upon stimulation by AMPs, the virulent S. aureus can induce high expression of a phenol-soluble modulin transporter (Pmt) system. CONCLUSION: Pediatric patients can be colonized by virulent S. aureus clones, which are able to resist AMPs' killing through the Pmt system. The residence of virulent strains necessitates the continuous monitoring of potential infections, as well as annealing, to take protective decolonization measures.

Lithium Storage Performance Boosted via Delocalizing Charge in Znx Co1- x PS3 /CoS2 of 2D/3D Heterostructure.

A promising anode material consisting of bimetallic thiophosphate Znx Co1- x PS3 and CoS2 with 2D/3D heterostructure is designed and prepared by an effective chemical transformation. Density functional theory calculations illustrate that the Zn2+ can effectively modulate the electrical ordering of Znx Co1- x PS3 on the nanoscale: the reduced charge distribution emerging around the Zn ions can enhance the local built-in electric field, which will accelerate the ions migration rate by Coulomb forces and provide tempting opportunities for manipulating Li+ storage behavior. Moreover, the merits of the large planar size enable Znx Co1- x PS3 to provide abundant anchoring sites for metallic CoS2 nanocubes, generating a 2D/3D heterostructure with a strong electric field. The resultant Znx Co1- x PS3 /CoS2 can offer the combined advantages of bimetallic alloying and heterostructure in lithium storage applications, leading to outstanding performance as an anode material for lithium-ion batteries. Consequently, a high capacity of 794 mA h g-1 can be retained after 100 cycles at 0.2 A g-1 . Even at 3.0 A g-1 , a satisfactory capacity of 465 mA h g-1 can be delivered. The appealing alloying-heterostructure and electrochemical performance of this bimetallic thiophosphate demonstrate its great promise for applications in practical rechargeable batteries.

Cubic Manganese Potassium Hexacyanoferrate Regulated by Controlling of the Water and Defects as a High-Capacity and Stable Cathode Material for Rechargeable Aqueous Zinc-Ion Batteries.

Aqueous zinc ion batteries (A-ZIBs) have been used as new alternative batteries for grid-scale electrochemical energy storage because of their low cost and environmental protection. Finding a suitable and economical cathode material, which is needed to achieve high energy density and long cycle stability, is one of the most important and arduous challenges at the present stage. Potassium manganese hexacyanoferrate (KMHCF) is a kind of Prussian blue analogue. It has the advantages of a large 3D frame structure that can accommodate the insertion/extraction of zinc ions, and is nontoxic, safe, and easy to prepare. However, regularly synthesized KMHCF has higher water and crystal defects, which reduce the possibility of zinc ions' insertion/extraction, and subsequently the discharge capacity and cycling stability. In this work, a KMHCF material with less water and low defects was obtained by adding polyvinylpyrrolidone during the synthesis process to control the reaction process. The KMHCF serves as the cathode of A-ZIBs and exhibits an excellent electrochemical performance providing a specific capacity of 140 mA h g-1 for the initial cycle at a current density of 100 mA g-1 (1 C). In particular, it can maintain a reversible capacity of 85 mA h g-1, even after 400 cycles at 1 C. Moreover, unlike the traditional zinc storage mechanism of A-ZIBs, we found that the KMHCF electrode undergoes a phase transition process when the KMHCF electrode was activated by a small current density, which is attributed to part of the Mn on the lattice site being replaced by Zn, thus forming a new stable phase to participate in the subsequent electrochemical reaction.

The cytoplasmic loops of AgrC contribute to the quorum-sensing activity of Staphylococcus aureus.

In Staphylococcus aureus, the accessory gene regulator (agr) quorum-sensing system is thought to play an important role in biofilm formation. The histidine kinase AgrC is one of the agr system components and activated by the self-generated auto-inducing peptide (AIP), which is released continuously into the extracellular environment during bacterial growth. The extracellular loops (Extra-loops) of AgrC are crucial for AIP binding. Here, we reported that the cytoplasmic loops (Cyto-loops) of AgrC are also involved in Agr activity. We identified S. aureus ST398 clinical isolates containing a naturally occurring single amino acid substitution (lysine to isoleucine) at position 73 of an AgrC Cyto-loop that exhibited significantly stronger biofilm formation and decreased Agr activity compared to the wild-type strain. A constructed strain containing the K73I point mutation in AgrC Cyto-loop continued to show a growth dependent induction of the agr system, although the growth dependent induction was delayed by about 6 h compared to the wild-type. In addition, a series of strains containing deletion mutants of the AgrC Cyto- and Extra-loops were constructed and revealed that the removal of the two Cyto-loops and Extra-loops 2 and 3 totally abolished the Agr activity and the growth-dependence on the agr system induction. Remarkably, the Extra-loop 1 deletion did not affect the Agr activity. In conclusion, the AgrC Cyto-loops play a crucial role in the S. aureus quorum-sensing activity.

Roles of the Site 2 Protease Eep in Staphylococcus aureus.

In Enterococcus faecalis, the site 2 protease Eep generates sex pheromones, including cAM373. Intriguingly, in Staphylococcus aureus, a peptide similar to cAM373, named cAM373_SA, is produced from the camS gene. Here, we report that the staphylococcal Eep homolog is not only responsible for the production of cAM373_SA but also critical for staphylococcal virulence. As with other Eep proteins, the staphylococcal Eep protein has four transmembrane (TM) domains, with the predicted zinc metalloprotease active site (HEXXH) in the first TM domain. eep deletion reduced the cAM373_SA activity in the culture supernatant to the level of the camS deletion mutant. It also markedly decreased the cAM373 peptide peak in a high-performance liquid chromatography (HPLC) analysis. Proteomics analysis showed that Eep affects the production and/or the release of diverse proteins, including the signal peptidase subunit SpsB and the surface proteins SpA, SasG, and FnbA. eep deletion decreased the adherence of S. aureus to host epithelial cells; however, the adherence of the eep mutant was increased by overexpression of the surface proteins SpA, SasG, and FnbA. eep deletion reduced staphylococcal resistance to killing by human neutrophils as well as survival in a murine model of blood infection. The overexpression of the surface protein SpA in the eep mutant increased bacterial survival in the liver. Our study illustrates that in S. aureus, Eep not only generates cAM373_SA but also contributes to the survival of the bacterial pathogen in the host.IMPORTANCE The emergence of multidrug-resistant Staphylococcus aureus makes the treatment of staphylococcal infections much more difficult. S. aureus can acquire a drug resistance gene from other bacteria, such as Enterococcus faecalis Intriguingly, S. aureus produces a sex pheromone for the E. faecalis plasmid pAM373, raising the possibility that S. aureus actively promotes plasmid conjugation from E. faecalis In this study, we found that the staphylococcal Eep protein is responsible for sex pheromone processing and contributes to the survival of the bacteria in the host. These results will enhance future research on the drug resistance acquisition of S. aureus and can lead to the development of novel antivirulence drugs.

Gold nanorod@iron oxide core-shell heterostructures: synthesis, characterization, and photocatalytic performance.

Iron oxides are directly coated on the surface of cetyl-trimethylammonium bromide (CTAB)-capped gold nanorods (AuNRs) in aqueous solutions at room temperature, which results in AuNR@Fe2O3, AuNR@Fe3O4, and AuNR@Fe2O3@Fe3O4 core-shell heterostructures. The iron oxide shells are uniform, smooth, with characteristic porous structure, and their thickness can be readily tuned. The shell formation is highly dependent on the reaction parameters including pH and CTAB concentration. The Fe2O3 shell is amorphous and exhibits nearly zero remanence and coercivity, while the Fe3O4 shell is ferromagnetic with a low saturation magnetization of about 0.5 emu g-1 due to its low crystallinity and the porous structure. At elevated temperatures achieved by plasmonic heating of the Au core, the Fe2O3 shell transforms from amorphous to γ-Fe2O3 and α-Fe2O3 phases, while the Fe3O4 phase disappears because of the oxidation of Fe2+. A 1.4-fold increase of photocatalytic performance is observed due to the plasmonic resonance provided by the Au core. The photocatalytic efficiency of Fe3O4 is about 1.7-fold higher than Fe2O3 as more surface defects are present on the Fe3O4 shell, promoting the adsorption and activation of reagents on the surface during the catalytic reactions. This approach can be readily extended to other nanostructures including Au spherical nanoparticles and nanostars. These highly uniform and multifunctional core-shell heterostructures can be of great potential in a variety of energy, magnetic, and environment applications.

Research on fuzi based on animal thermotropism behavior to discover if it has fewer "hot" characteristics without Ganjiang.

OBJECTIVE: To investigate whether fuzi (Radix Aconiti Praeparata) has fewer "hot" characteristics when administered without Ganjiang (Rhizoma Zingiberis). METHODS: Differences in the thermotropism behaviors of mice treated either with fuzi (Radix Aconiti Praeparata), Ganjiang (Rhizoma Zingiberis) or the combination of the two given intragastrically were investigated using the Animal Thermotropism Behavior Surveillance System. The water intake volume, oxygen consumption volume, adenosine triphosphatase (ATPase) activity, total antioxidant capacity (T-AOC) and total superoxide dismutase (T-SOD) activity were determined during the investigation. RESULTS: When fuzi and ganjiang were administered together, the rate at which mice remained on a warm plate ("remaining rate") and the times and distances of their movement were all significantly reduced (P < 0.05). Compared with the Normal group, the reduction was 55.1%, 48.3% and 44.8%, while compared with the Fuzi group, the reduction was 57.6%, 34.3% and 36.0%, indicating that "cold" tropism was significantly increased. Compared with the normal and fuzi groups, the ATPase activity and the respiratory oxygen consumption volume of the fuzi + ganjiang group were significantly increased (P < 0.05), suggesting an improvement in energy metabolism and showing a "hot" characteristic when Fuzi and Ganjiang are present together. Additionally, the T-AOC and T-SOD activity were significantly enhanced (P < 0.05). CONCLUSION: The behavior of mice tending toward "cold" tropism can be regarded as a quantitative reflection of Fuzi having fewer characteristics consistent with a "hot" nature when not used with Ganjiang, the functional mechanism of which may be a change in the ATPase activity in liver tissue.

Study on drug property differences of shexiang (moschus) and bingpian (borneolum synthcticum) based on analysis of biothermodynamics.

OBJECTIVE: To study the drug property differences of Shexiang (Moschus) and Bingpian (Borneolum Synthcticum) with biothermodynamics, and to verify the objectivity and authenticity of the drug property. METHODS: The growth-thermogram curves of Escherichia coli (E. coli) affected by Shexiang (Moschus) and Bingpian (Borneolum Synthcticum) at different concentrations were determined with microcalorimetry, and the power-time curves (thermogram curves) of E. coli metabolism and characteristic parameters, such as growth rate constant (k), maximum output power (P(m)), peak time (t(p)), total heat-output (Q(t)), etc. were analyzed with the principal component analysis (PCA) to find the close correlative parameters, so as to objectively reflect the drug property differences of Shexiang (Moschus) and Bingpian (Borneolum Synthcticum). RESULTS: The values of P2 in the second exponential growth phase increased with the increase of the concentrations of Shexiang (Moschus) and Bingpian (Borneolum Synthcticum), and the P2 of Shexiang (Moschus) was larger than that of Bingpian (Borneolum Synthcticum); Q2 increased with the increase of the concentrations of Shexiang (Moschus), but for Bingpian (Borneolum Synthcticum) it was opposite. It is indicated that they have different effects on P2 and Q2 of E. coli in the second exponential growth phase, and have differences in warm and cold natures. CONCLUSION: The microcalorimetry can accurately and objectively appraise differences of the drug property of Shexiang (Moschus) and Bingpian (Borneolum Synthcticum) and verify the objectivity and authenticity of the drug property, so as to provide a new and useful method for studies of the drug property of Chinese drugs.

Study on the complex prescription compatibility law of the cold and hot nature of Mahuang Decoction and its categorized formulae based on the cold-hot pad differentiating assay.

OBJECTIVE: To explore the complex prescription compatibility law of the cold and hot nature of Mahuang Decoction (, MHD) and Maxing Shigan Decoction (, MXSGD), both categorized both categorized MHD) and Maxing Shigan Decoction (both categorized MXSGD), both categorized formulas but with different hot/cold natures. METHODS: Oxygen consumption of mice was determined among three groups: MHD, MXSGD and the control; a cold-hot pad differentiating assay was used to observe the variability of temperature tropism among the groups of mice which was treated with MHD, MXSGD, and their compositions. Meanwhile, the total anti-oxidant capability (T-AOC) activity were detected. RESULTS: After administration of MHD, the mice showed increased oxygen consumption (P<0.01). Compared with MHD group, the remaining rate of MXSGD mice on the hot pad was found to be significantly increased with the cold-hot pad differentiating assay (P<0.05). There was no significant difference (P>0.05) among the remaining rates of MXSGD, MXSGD with high dose Gypsum Fibrosum (MXHGF) group, and MXSGD with low dose Gypsum Fibrosum (MXLGF) group mice. Compared with the MHD group, T-AOC activity of the mice in the Consensus Compositons group was significantly decreased (P=0.0494). Compared with the MXSGD group, T-AOC activity of Gypsum Fibrosum (GF) group was increased significantly (P=0.0013). CONCLUSIONS: The differences in cold and hot nature could be represented objectively between MHD with a hot nature and MXSGD with a cold nature. The reason may be the Gypsum Fibrosum which decreased the efficacy of the consensus compositions. However, increasing or decreasing the dose of Gypsum Fibrosum will not change the cold and hot nature of MXSGD.

[Effect of zuojin pill and fanzuojin pill on the growth metabolism of enterobacteria by microcalorimetry].

OBJECTIVE: To study the effects of Zuojin Pill and Fanzuojin Pill (ZJP and FZJP) on the growth metabolism of enterobacteria from the biothermodynamic viewpoint, and to objectively validate the difference between the two drugs for investigating a new way in congener Chinese drugs research. METHODS: The growth metabolism power-time curves of enterobacteria affected by ZJP and FZJP in different concentrations were obtained by microcalorimetry. And the activities of the two drugs were assessed depending some related characteristic parameters, including growth rate constant (k), maximum output power (P(max)), peak time (T(p)) , maximum heat-output (Q1), and bacteria inhibition rate (I). RESULTS: With the drugs' concentration increasing, T(p) was prolonged, k value reduced in enterobacteria, i.e. , the two drugs both inhibited the growth of enterobacteria in different extents. Comparison of inhibiting rates showed that the bacteriostasis activity of ZJP was greater than that of FZJP. CONCLUSIONS: There was objective difference in activities of inhibiting enterobacteria between ZJP and FZJP. Microcalorimetry could express the features at real-time, on-line and sensitively. It was able to determine the activity of drugs accurately and quickly in appraising congener Chinese drugs, like ZJP and FZJP, by microcalorimetry.

Microcalorimetric study of the effect of Benzoinum and Styrax on the growth of Escherichia coli.

In this study, the effects of Benzoinum and Styrax on Escherichia coli (E. coli) growth were investigated by microcalorimetry. Using a TAM Air Isothermal Calorimeter, ampoule method, the power-time curves of E. coli growth at 37°C affected by Benzoinum and Styrax were measured. By analysing some quantitative thermokinetic parameters, such as growth rate constants k, the maximum heat-out power Pm, the time of the maximum heat-out power tm, the total heat production Qt and inhibitory ratio I, one could find that low concentrations (0-3.9 mg mL(-1)) of Benzoinum and Styrax had stimulation effects on E. coli growth, and high concentrations (7.8-125.0 mg mL(-1)) of these two drugs would inhibit the growth of the bacteria. The antibacterial effects of Benzoinum and Styrax can also be expressed as half inhibitory concentration IC50. The IC50 values for Benzoinum and Styrax are 78.5 and 88.0 mg mL(-1), respectively, which suggests that the antibacterial effect of Benzoinum on E. coli was much stronger than that of Styrax. This study provides a useful method to investigate the effects of herbal medicines on microbes. It also supplies some references for the application of Benzoinum and Styrax in clinical treatment.

[COLD or HOT natural attribute of Zuojinwan and Fanzuojinwan based on temperature tropism of mice].

This study is to investigate the authenticity between COLD and HOT natural attribute in the famous Chinese medicine formulas--Zuojinwan (Coptis-Evodia 6 : 1) and Fanzuojinwan (Coptis-Evodia 1 : 6) based on mice temperature tropism, and establish an objective method to estimate the difference of two natural attribute by using a cold/hot plate differentiating technology. The results indicated that the COLD nature Zuojinwan could decrease significantly the remaining rate of HOT-symptom rat on warm pad (P < 0.05). That was not notable to COLD-symptom rat. The interference result of COLD-HOT temperature tropism to COLD/HOT symptom rat in Fanzuojinwan was the reverse with the COLD nature Zuojinwan. Meanwhile, biochemical indicators which are relative to energy metabolism such as ATPase enzyme activity and total anti-oxidant capability (T-AOC), had corresponding change in the organism. In the study, the COLD and HOT natural tendency in Zuojinwan and Fanzuojinwan which were composed by the same herbs with different proportion could be expressed qualitatively, quantitatively, objectively and directly with applying animal temperature tropism, and be verified to philosophical idea of treating disease theory with "expelling heat with cold herbs and cryopathy requiring warm prescription", not "expelling heat with heat herbs and cryopathy requiring cold prescription" in ancient traditional Chinese medicine, which brings a new approach in investigation of the nature theory of traditional Chinese medicine.