Benefits of environmental information disclosure in managing water pollution: evidence from a quasi-natural experiment in China.

Environmental information disclosure (EID) is playing an increasingly important role in water pollution management. However, since EID is hard to measure and other endogeneity problems, it is difficult to capture the causal inference between the two. Using the difference-in-difference method, this paper takes advantage of the Pollution Source Regulatory Information Disclosure Index (PITI) program promulgated by China in 2008 as a quasi-natural experiment to empirically capture the net effect of EID on water pollution management and its impact mechanism. The results show that from the average treatment effects perspective, the PITI strongly promote water pollution management. However, the dynamic effects of PITI present a decreasing and weakening trend over time. Further mechanism analysis reveals that PITI improves water pollution management mainly through the technological innovation effect. Several robustness checks justify our findings. Heterogeneity analysis shows that the PITI has a greater positive impact on water pollution management in cities located in the southern areas and with high economic levels and with a larger population.

Computational Insights into the Catalytic Mechanism of Bacterial Carboxylic Acid Reductase.

Multidomain carboxylic acid reductases (CARs) can reduce a wide range of carboxylic acids to the corresponding aldehydes in the presence of ATP and NADPH. Recent X-ray structures of the individual (di)domains of Segniliparus rugosus CAR (SrCAR) shed light on the catalysis mechanism and revealed domain dynamics during the different states of the reaction. However, the details of the catalytic mechanism of each step operated by the corresponding domains are still elusive. Toward this end, several models based on the crystal structures were constructed, and molecular dynamics simulations along with density functional theory (DFT) calculations were employed to elucidate the conformational dynamics and catalytic mechanism of SrCAR concealed to static crystallography. We investigated the roles of the key residues in the substrate binding pocket involved in the adenylation and thiolation reactions and especially determined the roles played by a nonconserved Lys528 residue in the thiolation step, which were further verified by site-directed mutagenesis. The reduction mechanism of SrCAR, including the natures of the transition states for hydride and proton transfer, was also explored theoretically using the DFT method B3LYP. The information presented here is useful as a guide for the future rational design of CARs.

[Penetration acupuncture at Baxie(EX-UE 9) combined with rehabilitation for swelling hand of post-stroke shoulder-hand syndrome].

OBJECTIVE: To compare the effects between penetration acupuncture at Baxie (EX-UE 9) combined with rehabilitation and simple rehabilitation for swelling hand in post-stroke shoulder-hand syndrome. METHODS: Sixty patients were randomly assigned into an observation group and a control group,30 cases in each one. Penetration acupuncture at Baxie (EX-UE 9) combined with rehabilitation were used in the observation group,and the acupoints were the affected Baxie (EX-UE 9) and Wailaogong (EX-UE 8). Simple rehabilitation was used in the control group. All the treatment was given for 3 weeks,5 days a week with 2 days at the interval,once a day. The swelling degree and motor function of the affected hand were assessed before and after treatment in the two groups. Also,the effects were compared. RESULTS: The swelling and motor function scores after treatment were improved compared with those before treatment in the two groups(all P<0.01),with better effects in the observation group(both P<0.01). The total effective rate was 93.3%(28/30) in the observation group,which was better than 73.3%(22/30) in the control group(P<0.01). CONCLUSIONS: Penetration acupuncture at Baxie (EX-UE 9) combined with rehabilitation can effectively and timely alleviate the swelling hand and motor function of post-stroke shoulder-hand syndrome,which are better than simple rehabilitation.

Iron porphyrin carbenes as catalytic intermediates: structures, Mössbauer and NMR spectroscopic properties, and bonding.

Iron porphyrin carbenes (IPCs) are thought to be intermediates involved in the metabolism of various xenobiotics by cytochrome P450, as well as in chemical reactions catalyzed by metalloporphyrins and engineered P450s. While early work proposed IPCs to contain Fe(II), more recent work invokes a double-bond description of the iron-carbon bond, similar to that found in Fe(IV) porphyrin oxenes. Reported herein is the first quantum chemical investigation of IPC Mössbauer and NMR spectroscopic properties, as well as their electronic structures, together with comparisons to ferrous heme proteins and an Fe(IV) oxene model. The results provide the first accurate predictions of the experimental spectroscopic observables as well as the first theoretical explanation of their electrophilic nature, as deduced from experiment. The preferred resonance structure is Fe(II)←{:C(X)Y}(0) and not Fe(IV)={C(X)Y}(2-), a result that will facilitate research on IPC reactivities in various chemical and biochemical systems.

[Influence of acupuncture-drug compound anesthesia with different frequency electroacupuncture on immune function in patients undergoing pneumonectomy].

OBJECTIVE: To explore different frequency electroacupuncture in acupuncture-drug compound anesthesia on analgesic effect and immune function in the pulmonary resection patients in order to recommend the best electroacupuncture frequency in acupuncture-drug compound anesthesia. METHODS: One hundred and sixty-three patients scheduled for pneumonectomy were randomly divided into group A (n = 31), B (n = 34), C (n = 32), D (n = 34) and E (n = 32). Houxi (SI 3), Zhigou (TE 6), Neiguan (PC 6) and Hegu (LI 4) were selected in the five groups. Group A was treated with sham acupuncture by pasting needles without needle bodies at acupoints and electroacupuncture at the needle handle, and group B with 2 Hz electroacupuncture, and group C with 2 Hz/ 100 Hz electroacupuncture, and group D with 100 Hz electroacupuncture, and group E with 2 Hz/100 Hz transcetaneous acupoints electrical stimulation, and general anesthesia was produced in all the groups followed by 30 min electrical stimulation and the stimulation was lasted till the end of operation. The dosages of the anesthetics and the changes of surface antigen of leukomonocyte (CD3+ , CD4+ , CD8+ and CD4+/CD8+) and natural killer (NK) cell were observed at 1 day before surgery, intraoperative and 1 day after surgery. RESULTS: In comparison with group A, the dosages of Propofol in group B and D were decreased, Fentanyl in group B, D and E were decreased. CD3+ and CD4+ in 5 groups increased at first and then decreased over time (all P < 0.01), and group E and C could inhibit the decrease of CD3+ and CD4+ in postoperation in comparison with that in the other three groups (all P < 0.05). CD8+ in 5 groups has no change in different times (all P > 0.05), and group E and D could inhibit the decrease of CD8+ in postoperation in comparison with that in the other three groups (all P < 0.05). CD4+/CD8+ in 5 groups has no change in different times (all P > 0.05), and group E and C could inhibit the decrease of CD4+/CD8+ in postoperation in comparison with that in the other three groups (all P < 0.05). NK cells of 5 groups were increased gradually in different times (all P < 0.01), with the similar regulation of NK cells (all P > 0.05). CONCLUSION: Acupuncture-drug compound anesthesia with 2 Hz and 100 Hz electroacupuncture together with 2 Hz/100 Hz transcetaneous acupoints electrical stimulation have the best analgesic effect, and 2 Hz/100 Hz transcetaneous acupoints electrical stimulation and 2 Hz/100 Hz electroacupuncture have the best regulation of immune function. Acupuncture-drug compound anesthesia with 2 Hz/100 Hz transcetaneous acupoints electrical stimulation is recommended for that it can not only decrease the dosages of the anesthetics, but also significantly improve the immunosuppression in patients undergoing pneumonectomy.

Gradually accumulating beneficial mutations to improve the thermostability of N-carbamoyl-D-amino acid amidohydrolase by step-wise evolution.

To further enhance repeated batch reactions with immobilized N-carbamoyl-D-amino acid amidohydrolase (DCase), which can be used for the industrial production of D-amino acids, the stability of high soluble mutant DCase-M3 from Ralstonia pickettii CGMCC1596 was improved by step-wise evolution. In our previous report, six thermostability-related sites were identified by error-prone PCR. Based on the above result, an improved mutant B5 (Q12L/Q23L/H248Q/T262A/T263S) was obtained through two rounds of DNA shuffling, showing a 10°C increase in the T (50) (defined as the temperature at which heat treatment for 15 min reduced the initial activity by 50%) compared with the parental enzyme DCase-M3. Furthermore, several thermostability-related sites (Met(31), Asn(93), Gln(207), Asn(242), Glu(266), Thr(271), Ala(273)) on B5 were identified using amino acid consensus approach based on sequence alignment of homologous DCases. These sites were further investigated by iterative saturation mutagenesis (ISM), and a combinational mutant D1 (Q12L/Q23L/Q207E/N242G/H248Q/T262A/T263S/E266D/T271I/A273P) that enhanced the T(50) by about 16°C over DCase-M3 was obtained. Oxidative stability assay showed that the most heat-resisting mutant displayed only a slight increase in resistance to hydrogen peroxide. Comparative characterization showed that D1 not only maintained its characteristic high solubility but also shared similar k(cat) and K(m) values and optimum reaction pHs with the parental enzyme. The significantly improved mutants in the immobilized form are expected to be applied in the industrial production of D-p-hydroxyphenylglycine.

[Genome shuffling method of Bacillus subtilis].

Genome shuffling methods were explored for Bacillus subtilis strain molecular breeding. Recycling protoplast fusion, recycling transformation and recycling universal transduction were used for genome shuffling in B. subtilis. Four strains with different nutrition-deficiency markers were used as initial strains. After five rounds protoplast fusion, transformation or transduction, the descendant with 4 markers had not been detected, and the rate of descendant with 3 markers were 4.53 x 10(-4), 1.64 x 10(-4), 4.47 x 10(-3), respectively. A computer program was made to simulate the recycling fusion process. Based on simulation result and comparing the genome shuffling result of B. subtilis in this experiment and that of Streptomyces coelicolor reported in references, effective genome shuffling needs a high recombination rate of at least between 10(-3) and 10(-2).