The effects of reaction temperature, ethanol concentration and weight hourly space velocity (WHSV) on the ethylene production from ethanol dehydration using zinc, manganese and cobalt modified HZSM-5 catalyst were investigated by response surface methodology (RSM). The results showed that the most significant effect among factors was reaction temperature and the factors had interaction. The optimum conditions were found as 34.4% ethanol concentration, 261.3 0 degrees C of reaction temperature and 1.18 h(-1) of WHSV, under these conditions the yield of ethylene achieved 98.69%.
Catalysis ; Cobalt ; chemistry ; Dehydration ; Ethanol ; chemistry ; Ethylenes ; chemistry ; metabolism ; Manganese ; chemistry ; Zeolites ; chemistry ; Zinc ; chemistry

Animals ; Manganese ; chemistry ; Molecular Structure ; Organometallic Compounds ; chemical synthesis ; chemistry ; Superoxide Dismutase ; chemistry ; metabolism

OBJECTIVETo explore the biomarker of manganese exposure by analyzing the relationship between manganese exposure and concentration in some biomaterials.

METHODSThe air samples were collected through the individual air sample. According to the manganese levels in the air, workers were assigned to control group, low concentration group and high concentration group, and manganese in the hair, urine, serum, blood cell and saliva from different group were measured respectively. The correlations between concentration of external manganese exposure and manganese concentrations in biomaterials, and years of employment and concentrations in biomaterials were analyzed.

RESULTSIn the high concentration group, saliva manganese was 32.17 µg/L, hair manganese was 37.39 mg/kg, urine manganese was 2.50 µg/L, plasma manganese was 29.61 µg/L, blood manganese was 14.49 µg/L, were higher than those in the control group (10.40 µg/L, 1.60 mg/kg, 0.77 µg/L, 10.30 µg/L, 4.56 µg/L respectively) (P < 0.01). The manganese concentration in the saliva was significantly correlated with airborne manganese concentration (r = 0.649, P < 0.01), with the years of employment (r = 0.404, P < 0.01), with the total exposure of manganese (r = 0.342, P < 0.01), with the manganese concentration of plasma (r = 0.303, P < 0.01) and with the manganese concentration in blood cells (r = 0.359, P < 0.01), respectively.

CONCLUSIONSThe concentration of manganese in saliva could work as a biomarker of manganese internal exposure.

Adult ; Air Pollutants, Occupational ; analysis ; Biomarkers ; analysis ; Hair ; chemistry ; Humans ; Manganese ; analysis ; blood ; urine ; Manganese Poisoning ; prevention & control ; Middle Aged ; Occupational Exposure ; prevention & control ; Saliva ; chemistry ; Young Adult

Variation in pH value of oral cavity circumstance causes decayed tooth. In this paper, corrosions of Ti-Fe-Mo-Mn-Nb-Zr dental alloys in various pH lactic acids were studied by immersion test. In the case of pH=4, which is an acidity slightly larger than that causes decayed tooth, Ti-Fe-Mo-Mn-Nb-Zr alloys are entirely corrosion-resistant, and the corrosion type is pitting. With the increase in acidity, the corrosion-resistance of Ti-Fe-Mo-Mn-Nb-Zr alloys deteriorates, and the corrosion type changes from pitting to intergranular corrosion. Fe ion is the most dissolved substance in impregnation, which means Fe goes against the corrosion-resistance of Ti alloys. Both results of thermodynamics calculation and X-ray photoelectron spectroscopy have shown that Mn2O3, Nb2O5 and TiO2 form oxide film on the surface of Ti-Fe-Mo-Mn-Nb-Zr alloys.
Corrosion ; Dental Alloys ; chemistry ; Humans ; Hydrogen-Ion Concentration ; Iron ; chemistry ; Lactic Acid ; chemistry ; Manganese ; chemistry ; Molybdenum ; chemistry ; Niobium ; chemistry ; Surface Properties ; Titanium ; chemistry ; Zirconium ; chemistry

OBJECTIVES: In order to evaluate the degree of manganese exposure and its health hazards effect on welders in manufacturing industry. METHODS: The author measured airborne, blood and urine concentrations of manganese and blood chemistry, and also observed clinical symptoms and signs on 60 welders for case an.d 60 non-welders for control working in manufacturing industry by age maching method. RESULTS: The geometric means of blood and urine concentrations of manganese were 1.13 +/- 1.38 microgram /dI and 2.52 +/- 1.37 microgram /I for Welders group, 1.09 +/- 1.68 microgram /dl and 1.86 +/- 1.34 microgram / I for Non-welders group. Airborne concentration of manganese was 0. 15 +/- 1.66 mg/m3 for exposured group, and the urinary mean concentration of manganese was statistically significant difference between exposured and non-welders group (P < 0.05). Clinical signs in welders group were palmomentle reflex (23.3%), tremor (20.0%) and grabellar sign (5.0%). Symptoms in welders group were fatigue (66.7%), amnesia (66.7%), excessive sweating (51.7%), nervousness (51.7%), general weakness (48. 3%) and arthralgia (46.7%) and so on, and there was statistically significant difference compared to non-welders group (P<0.05). Manganese exposure effects on blood chemistry were not observed. There were statistically significant correlation between manganese concent- ration in blood and urine (r=0. 269), airborne and urine (r=0. 601) and airborne and blood (r=0. 268). CONCLUSION: The author suggest that further studies are followed to evaluate the health status of welders whose blood and urine manganese concentrations were below normal reference level, and to establish the questionnaire and the diagnostic tools for early detecting the chronic manganese poisioning on welders.
Amnesia ; Anxiety ; Arthralgia ; Chemistry ; Fatigue ; Manganese* ; Questionnaires ; Reflex ; Sweat ; Sweating ; Tremor

The transplants of one-year-old Glycyrrhiza uralensis Fisch. were subjected to five concentrations of MnSO4-H2O (0, 1.81, 18.1, 36.2 and 54.3 mg·L(-1)) culturing in vermiculite. qRT-PCR and HPLC were respectively used to measure the relative expression of SQS1 gene and the content of glycyrrhizic acid of G. uralensis in different concentrations of MnSO4·H2O. This is to explore discuss the effects of the expression of SQS1 gene and the accumulation of glycyrrhizic acid by Mn treatment. The results showed both the expression of SQS1 gene and the content of glycyrrhzic acid of G. uralensis tended to rise after the fall of the first with the increase of concentration of Mn treatment. And they were of very significant positive correlation (P<0.01, r=0.737). Relative expression of SQS1 gene reached the highest 7.90 under 18.1 mg·L(-1) MnSO4·H2O treatment. It was very significantly different between 18.1 mg·L(-1) concentration of MnSO4·H2O treatment and CK (0 mg·L(-1)), 1.81, 36.2 and 54.3 mg·L(-1) (P<0.01), and 1.75, 1.37, 1.37, 2.33 times respectively. The content of glycyrrhizic acid reached the highest under 1.81 and 18.1 mg·L(-1) MnSO4·H2O treatment, and there were not significant difference (P>0.05). It was very significantly different between them and other concentrations of MnSO4·H2O treatment (P<0.01). This study suggests the appropriate concentration of Mn treatment could certain promote the expression of SQS1 gene and the accumulation of glycyrrhizic acid of G. uralensis.
Chromatography, High Pressure Liquid ; Genes, Plant ; Glycyrrhiza uralensis ; chemistry ; genetics ; Glycyrrhizic Acid ; analysis ; Manganese

With the sulfate as the materials and NaOH as precipitator, Mn(0.4)Zn(0.6)Fe2O4 nanoparticles were produced, which are proved to be spinel Mn-Zn ferrite analyzed by X-ray diffraction(XRD). Their shapes are approximately global examined by transmission electron microscopy(TEM) and their average diameter is 50 nm measured with image analysis-system. The Curie temperature was measured and in vitro heating test in a alternating magnetic field was carried out. The results show that the Curie temperature is 105. 407 degrees C, While its magnetic fluid could rise to 43 degrees C - 47 degrees C due to different concentration in a alternating magnetic field. The result provide theoretical and practical evidence to select an appropriate material and concentration for tumor
Electromagnetic Fields ; Ferric Compounds ; chemistry ; Humans ; Hyperthermia, Induced ; instrumentation ; Manganese Compounds ; chemistry ; Metal Nanoparticles ; chemistry ; Microscopy, Electron, Transmission ; Neoplasms ; therapy ; X-Ray Diffraction ; Zinc Compounds ; chemistry

OBJECTIVETo observe the ability of triple helix-forming oligonucleotides (TFO) modified with manganese porphyrin to combine with and cleave HBV DNA fractions.

METHODSThe ends of TFO were modified with manganese porphyrin and acridine; At 37 degrees C and pH 7.4 condition in vitro, TFO modified with manganese porphyrin and acridine were bound with 32P labeled HBV DNA fragments, the affinity and specificity binding to target sequence were tested by electrophoretic mobility shift and DNase 1 footprinting assays, the ability to cleave HBV DNA fractions was observed with cleavage experiments.

RESULTSTFO modified with manganese porphyrin and acridine could bind to target sequence in a sequence-dependent manner with Kd values of 3.5 x 10(-7) mol/L and a relative affinity of 0.008. In the presence of KHSO5, TFO modified with manganese porphyrin and acridine could cleave target sequence in the region forming triple DNA.

CONCLUSIONIn the presence of KHSO5, TFO modified with manganese porphyrin and acridine could cleave target HBV-DNA in sequence-dependent manner.

Binding, Competitive ; DNA Fingerprinting ; Deoxyribonuclease I ; metabolism ; Electrophoretic Mobility Shift Assay ; Hepatitis B virus ; genetics ; Manganese ; chemistry ; Metalloporphyrins ; chemistry ; Nucleic Acid Conformation ; Oligodeoxyribonucleotides ; chemistry ; genetics ; metabolism

D-psicose 3-epimerase (DPEase) is demonstrated to be useful in the bioproduction of D-psicose, a rare hexose sugar, from D-fructose, found plenty in nature. Clostridium cellulolyticum H10 has recently been identified as a DPEase that can epimerize D-fructose to yield D-psicose with a much higher conversion rate when compared with the conventionally used DTEase. In this study, the crystal structure of the C. cellulolyticum DPEase was determined. The enzyme assembles into a tetramer and each subunit shows a (β/α)(8) TIM barrel fold with a Mn(2+) metal ion in the active site. Additional crystal structures of the enzyme in complex with substrates/products (D-psicose, D-fructose, D-tagatose and D-sorbose) were also determined. From the complex structures of C. cellulolyticum DPEase with D-psicose and D-fructose, the enzyme has much more interactions with D-psicose than D-fructose by forming more hydrogen bonds between the substrate and the active site residues. Accordingly, based on these ketohexose-bound complex structures, a C3-O3 proton-exchange mechanism for the conversion between D-psicose and D-fructose is proposed here. These results provide a clear idea for the deprotonation/protonation roles of E150 and E244 in catalysis.
Binding Sites ; Biocatalysis ; Catalytic Domain ; Clostridium cellulolyticum ; enzymology ; Hexoses ; chemistry ; Manganese ; chemistry ; Protein Structure, Quaternary ; Racemases and Epimerases ; chemistry ; metabolism ; Substrate Specificity

To estimate the manganese (Mn, below) exposure of workers in the ferromanganese manufacture factory and to evaluate its health effects, airborne, blood and urine Mn concentration measurements, questionnaire and other neurologic examinations were performed on 80 Mn-handing productive male workers (exposed group), 47 non-Mn-handling productive male workers (internal control group) and 144 productive male workers in other factory (external control group). The results obtained were as follows; The highest airborne Mn fume concentration among the work process was found at charging (0.42 mg/m3), and ferromanganese crushing process (1.14 mg/m3) was the highest in Mn dust. However all of them were below threshold limit value. Mean Mn concentrations in blood and urine of crushing workers were higher than those of other part workers. Among all of them, workers whose urine Mn concentration were exceed normal reference level (10 microgram/l) were 31 (18.5%). There was statistically significant correlation between airborne and urine Mn concentration (r=0.60), and so between airborne and blood Mn concentration (r=0.49), while there was no statistically significant correlation between blood and urine Mn concentration. Mean Mn concentration in airborne (0.60 mg/m3), urine (6.92 microgram/l) and blood (3.16 microgram/dl) in exposed group were significantly higher than those of control groups (p<0.01). Clinical symptoms such as excessive sweating, hypoesthesia, libido change, anosmia, decreased visual acuity and difficulty in writing showed higher positive rate in exposed group. Positive rate of clinical signs such as eye blinking and masked face in exposed group was higher than external control group. However clinical and laboratory findings such as blood pressure, blood chemistry, grip strength in exposed group were not statistically different from those of control groups. The results suggested that further studies were followed to evaluate the workers whose blood Mn concentration were below normal reference level but urine Mn concentrations above normal reference level, and to establish the questionnaire and the diagnostic tools to detect the Mn poisoning workers early.
Blinking ; Blood Pressure ; Chemistry ; Dust ; Hand Strength ; Humans ; Hypesthesia ; Libido ; Male ; Manganese* ; Masks ; Neurologic Examination ; Olfaction Disorders ; Poisoning ; Questionnaires ; Sweat ; Sweating ; Visual Acuity ; Writing