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M Xin

Publications and source records attributed to M Xin.

10 recordsLinked to original sources
PubMed2005

Air-soil exchange of mercury from background soils in the United States.

The air-surface exchange of mercury (Hg) was measured, using a dynamic polycarbonate flux chamber, for soils with low or "background" Hg concentrations (<0.1 mg/kg) at eleven locations across the contiguous United States. Sampling locations included agricultural, desert, grassland, mixed and pine forest ecosystems (n=1326 soil flux measurements at 46 individual sites). An overall soil Hg flux of 0.9+/-0.2 ng/m2/h for these background soils was obtained by averaging the means for the different locations. Soil Hg fluxes were significantly lower in dark conditions than in the light for all but the grassland sites. Mean inlet air Hg concentrations were 1.0+/-0.1 ng/m3 in the dark and 1.3+/-0.2 ng/m3 in the light. Soil temperature inside and outside of the chamber, air temperature, relative humidity, and irradiance were measured concurrently with soil Hg flux. Soil-air Hg exchange was weakly predicted by environmental variables (R2 from 0.07 to 0.52). For a single location, flux was better correlated with soil moisture than other measured environmental parameters, suggesting that soil moisture might be an important driver for Hg emissions from background soils. In addition, based on data collected we suggest some quality control measures for use of Tekran 2537A analyzers when measuring low mercury fluxes. Using basic scaling procedures, we roughly estimate that natural emissions from soils in the contiguous U.S. release approximately 100 Mg/yr of Hg to the atmosphere.

Agriculture↗
PubMed2001

[Kinetics of in vitro drug release from chitosan and N-alkyl chitosan membranes].

By using the so-called "lag-time" method, we studied the effect of membrane thickness(h), initial drug concentration(Co) and flow rate(V) on the difusion coefficient(D) of model drug in membranes. The experiment indicates that D increases as h and v increase; D Keeps constant when C0 changes; Under the same condition, the D value of N-alkyl chitosan membrane is bigger than that of pure chitosan membrane.

Chitin↗
PubMed2000

[Effect of temperature on the activity of some enzymes representative of EMP pathway and TCA cycle in psychrophilic yeast].

Some key enzymes of EMP pathway and TCA cycle in a psychrophilic yeast Y18 were studied in this paper compared with those of Saccharomyces cerevisiae. The results indicated that fructose, 1,6-bisphosphate aldolase, succinate dehydrogenase, and hexokinase in Y18 were very thermolabile and have high activity at low temperature. These enzymes belong to cold-active enzymes. Alpha-ketoglutarate dehydrogenase existed possibly in isoenzyme which had different temperature characteristics. Citrayl synthetase was very similar in temperature characteristics to that of mesophiles. The Km value of succinate dehydrogenase both from Y18 and S. cerevisiae were studied and Some features of enzyme in psychrophiles were also discussed in this paper.

Cryptococcus↗
PubMed1998

[Clinical study on Shenqi Fuzheng injection combined with chemotherapy in treating malignant tumor of digestive tract].

OBJECTIVE: To assess the clinical effect and safety of Shenqi Fuzheng Injection (SQFZI) combined with chemotherapy in treating malignant tumor of digestive tract. METHODS: One hundred and eighty-two patients were randomly divided into 3 groups, the combined therapy group (Group A), the SQFZI group (Group B) and the chemotherapy group (Group C). The remission and stabilization effect on cancer were observed. RESULTS: The remission rate and stabilizing rate of Group A were 20.2% and 87.9%, and those of the Group C were 15.6% and 68.9%, the difference between the two groups was significant, P < 0.05. The symptom and living quality improving rate of Group A were 78.8% and 42.4% separately, those of the Group B were 73.7% and 68.4% and of the Group C 37.8% and 26.7% respectively, the inter-group differences were significant, P < 0.05. The weight gain rate and effective rate of Group A were 45.5% and 90.9%, of Group C were 13.3% and 40.0%, P < 0.05. SQFZI showed good protective effect on hematopoietic system, 7.7% patients in Group A with WBC count lower than 4 x 10(9)/L after treatment, while in Group C, the percentage reached 22.2%. Moreover, SQFZI could raise activity of NK cell, macrophage and T-lymphcyte subgroups, without any injury on heart, liver and kidney function or other adverse reaction. CONCLUSION: SQFZI combined with chemotherapy has certain effect of remitting and stablizing on digestive tract tumor, the clinical effect is significant to patients with Qi-Deficiency, and is safe and reliable.

Adult↗
PubMed1996

[Detection of chromosome aberrations in brain gliomas by primed in situ labelling].

To investigate the possibility of applying the primed in situ labelling (PRINS) method to detect chromosome aberrations in brain gliomas and eventually for pathological diagnosis, PRINS with chromosome 10 and 12 centromere specific primers as well as chromosome 1 telomere specific primer was carried out on tissues from 5 brain glioma cases, of which 4 cases were found to have monosomy 10 or loss of one copy of chromosome 10. The remaining case was found to have trisomy 12 and multi-copies of chromosome 1. It is suggested that PRINS is a new molecular cytological bio-technique which is faster, simpler and more efficient than conventional fluorescence in situ hybridization, and which may be clinically applied to detect chromosome aberrations in brain gliomas in the future.

Brain Neoplasms↗
PubMed1995

NudF, a nuclear migration gene in Aspergillus nidulans, is similar to the human LIS-1 gene required for neuronal migration.

During a study of the genetics of nuclear migration in the filamentous fungus Aspergillus nidulans, we cloned a gene, nudF, which is required for nuclear migration during vegetative growth as well as development. The NUDF protein level is controlled by another protein NUDC, and extra copies of the nudF gene can suppress the nudC3 mutation. nudF encodes a protein with 42% sequence identity to the human LIS-1 (Miller-Dieker lissencephaly-1) gene, which is required for proper neuronal migration during brain development. This strong similarity suggests that the LIS-1 gene product may have a function similar to that of NUDF and supports previous findings to suggest that nuclear migration may play a role in neuronal migration.

Amino Acid Sequence↗
PubMed1994

A new kind of fasciolicide: molecular and electronic structures of some o-hydroxybenzenesulfonanilides.

The molecular and electronic structures of some fasciolicidal o-hydroxybenzenesulfonanilides (HBSA) have been studied using X-ray diffraction and semiempirical MO calculation. In these compounds, the phenolic hydroxyl forms a strong intramolecular hydrogen bond with an adjacent sulfonyl oxygen atom and the strength of the d-p dative S<--N bond, which may control the electron delocalization throughout the entire molecule, is affected by substituents on the phenyl rings on both sides. Owing to the poor delocalization, the contribution of the keto-form of the resonance structure is larger for some phenolate anions of HBSA in solution, and this may be a key factor determining the potency of fasciolicidal activity of HBSA.

Anilides↗