HCO_3^-/Cl^- 交换与细胞内酸碱调节

ＨＣＯ３－／Ｃｌ－交换与细胞内酸碱调节中国人民解放军第三军医大学附属新桥医院（６３００３７）张唐山１）①宁晓滨综述钱桂生杨晓静审校ＨＣＯ３－／Ｃｌ－交换又称“氯移”或Ｈａｎｂｕｒｇｅ移动，是由细胞膜上的阴离子交换载体（ＡＥ）或称为带了蛋白介导的〔１〕...

HCO_3^-/Cl^-交换与肺气体交换

HCO_3^-/Cl^-交换又称“氯移”或Hamburger移动,是由红细胞(RBC)膜上带3蛋白(band 3protein)介导的,该蛋白在哺乳动物RBC膜上约有一百万个分子。

Localized Corrosion and Phase Transformation of Simulated Archaeological Iron

The corrosion behaviors of simulated archaeological iron in solution （0.06 mol·L^-1 NaCl＋0.03 mol·L^-1 Na2SO4＋0.01 mol·L^-1 NaHCO3） simulating soil water composition was investigated by potentialdynamic polarization, constant potential polarization, and simulated occluded cell （O.C.） galvanostatic tests. X-ray diffraction （XRD）, energy dispersive spectrometry （EDS）, and scanning electron microscope （SEM） were used to study the corrosion morphology and the evolution of corrosion product. The objective was to discover the transformation process of archaeological iron, and determine the distribution of chlorinated corrosion products. The results showed that the presence of crevice, cavities, and channels facilitates the localized corrosion under rusts; the autocatalytic effect increases the concentration of Fe^2＋, Cl^-, and SO4^2- , and promotes local acidification within the crevices and cavities. Meanwhile, the phase transformation of corrosion products is concluded to proceed by means of two ways. One is that the ferrous ions are transformed into different kinds of FeOOH via the intermediate Fe（Ⅱ）-Fe（Ⅲ） hydroxyl-salt （i.e. Green Rusts）; the other is that the Fe^2＋ ions are transformed into FeCl2, FeCl3, and orange powders akaganeite at the crevices and cavities.

An ab initio study on single electron transfer between ClO_2 and phenol

The SET mechanism between chlorine dioxide （ClO2） and phenol was studied by using ab initio method at 4-31G* level. Geometries of the reactants, intermediate and products of the reaction were optimized and the single point energy calculations of the species were performed. The relative structure data of the reactants, intermediate and products are given.The SET mechanism between ClO2and phenol was confirmed by ab initio calculations. The reaction is exothermic about 200 88 kJ/mol.

Contribution of mononuclear bone marrow cells to carbon tetrachloride-induced liver fibrosis in rats

AIM： To study the inhibitory effect of mononuclear bone marrow cell （BNC） transplantation on carbon tetrachloride （CCl4） -induced liver fibrosis in rats. METHODS： Rat liver fibrosis models were induced by CCl4 and alcohol administration. After 8 wk, twenty rats were randomly allocated into treatment group （n = 10） and control group （n = 10）. BMC were infused into the rats in treatment group via the portal vein, while heparinized saline was infused in control group. CCl4 was hypodermically injected into the rats twice a week for 4 wk. At the end of wk 12, all rats were humanely sacrificed. Uver samples were taken and stained with HE or Masson trichrome. The general conditions, liver fibrosis （hydroxyproline and collagen fibre） and liver pathological grades in rats were evaluated. RESULTS： The general conditions of the rats in treatment group improved markedly, but not in control group. Hydroxyproline was 504.6± 128.8 μg/g in treatment group, and 596.0 ± 341.8 μg/g in control group. The percentage of collagen fibre was 3.75% ± 0.98% in treatment group and 5.02% ± 0.44% in control group. There was a significant difference between the two groups （P 〈 0.05）. Liver pathological grade decreased from grade N to grade 11 partially in treatment group （P 〈 0.05） with no obvious improvement in control group （P 〉 0.05）. There was a significant difference between treatment group and control group （P 〈 0.05）.CONCLUSION： Transplantation of BMC can improve liver fibrosis due to chronic liver injury in rats.

Properties of Novel Reactive Transfer Printing of Silk

The novel reactive transfer printing of silk was carried out through a hot-press adhesion and steaming. The special transfer paper was prepared by coating the paste mainly containing hot-melt adhesive hlgh-substituted hydroxypropyl cellulose （H-HPC） and printing thickener earboxymethyl cellulose （CMC）. The effects of each ingredient in the paste on color yield of the prints and dye penetration were investigated. The major results indicate that, color yield is chiefly governed by the adhesion extent imparted by H-HPC, the type of fixing alkaline agent, and the content of urea. Trichloroacetic acid （TCAA） as the fixing alkaline agent and adding 5% urea can enhance the color depth obviously. Dye penetration depends on the coating quantity on the transfer paper, the contents of urea and dicyandiamide. The printed silk possesses a higher color yield, color fastness of grade 3 or above, clear sharpness, and good handle when the paste contains 3 % H-HPC, 0. 7 % CMC, 3 % TCAA, 5 % urea, 3 % dicyandiamide, and 0. 5 % physical sorbent nano-silica.

Chloromycetin resistance of clinically isolated E coli is conversed by using EGS technique to repress the Chloromycetin acetyl transferase

AIM： To explore the possibility of repression of chloromycetin （Cm） acyl transferase by using external guided sequence （EGS） in order to converse the clinical E coli isolates from Cm- resistant to Cm- sensitive. METHODS： EGS directed against chloromycetin acetyl transferase gene （cat） was cloned to vector pEGFP-C1 which contains the kanamycin （Kin） resistance gene. The recombinant plasmid pEGFP-C1＋EGScatl＋cat2 was constructed and the blank vector without EGS fragment was used as control plasmids. By using the CaCl2 transformation method, the recombinant plasmids were introduced into the clinically isolated Cm resistant but Km sensitive E coli strains. Transformants were screened on LB agar plates containing Kin. Extraction of plasmids and PCR were applied to identify the positive clones. The growth curve of EGS transformed bacteria cultured in broth with Cm resistance was determined by using spectrophotometer at A600. Drug sensitivity was tested in solid culture containing Cm by using KB method. RESULTS： Transformation studies were carried out on 16 clinically isolated Cm-resistant （250 μg/mL of Cm） E colistrains by using pEGFP-C1-EGScatlcat2 recombinant plasmid. Transformants were screened on LB-agar plates containing Km after the transformation using EGS. Of the 16 tested strains, 4 strains were transformed successfully. Transformants with EGS plasmid showed growth inhibition when grown in liquid broth culture containing 200 μg/mL of Cm. In drug sensitivity test, these strains were sensitive to Cm on LB-agar plates containing 200 μg/mL of Cm. Extraction of plasmids and PCR amplification showed the existence of EGS plasmids in these four transformed strains. These results indicated that the Cat of the four clinical isolates had been suppressed and the four strains were converted to Cm sensitive ones. CONCLUSION： The EGS directed against Cat is able to inhibit the expression of Cat, and hence convert Cm- resistant bacteria to Cm-sensitive ones. Thus, the EGS has the capability of converting the phenotype of clinical drug-resistant isolates strains to drug-sensitive ones.

The Enrichment of Chloride Anion in the Occluded Cell and Its Effect on Stress Corrosion Crack of 304 Stainless Steel in Low Chloride Concentration Solution

The enrichment of chloride anion within the occluded cell （OC） for Type 304 austenitic stainless steel in low chloride concentration solution has been investigated by means of a simulated OC. The influence of the enrichment of chloride anion on stress corrosion crack （SCC） of Type 304 stainless steel has been studied. It was observed that the amount of chloride anion migration was proportional to the charge flowing through the anode. Owning to the effects of enrichment of chloride anion, low chloride concentration solution could induce SCC for Type 304 stainless steel.

Standard Gibbs Energies of Transfer for KBPh_4 from Water to Water+PrOH and Water+TBA Mixtures and the Primary Medium Effects

The standard Gibbs energies of transfer (Δ tr G 0) for potassium tetraphenylborate (KBPh 4) have been studied in the systems of water and water +1 propanol (PrOH) as well as water and water + t butyl alcohol (TBA) at 298.15?K. The results show that -Δ tr G 0 exhibits a complicated changing pattern with the mole fraction of TBA( x (TBA)) or PrOH ( x (PrOH)), and Δ tr G 0 has the a maximum value at x (TBA) = 0.2 or x (PrOH)=0.2. Especially, -Δ tr G 0 of KBPh 4 changes unusually with increasing x (TBA) when x (TBA) < 0.05. The reasons for these changes were analyzed and discussed.

Ab Initio Prediction of ^(29)Si-NMR Chemical Shifts

The ability of several ab initio models to predict experimental 29Si-NMR chemical shift is examined. The shielding values of trimethylsilyl chloride (A), t-butyldimethylsilyl chloride (B) and allyltrimethylsilane (C) are calculated by GIAO , CSGT and IGAIM methods, using HF/6-31G*, B3LYP/6-31G*, HF/6-311+G **, B3LYP/6-311+G ** and MPW1PW91/6-311+G ** models respectively. The 29Si chemical shifts calculated by GIAO method using HF/6-311+G ** model are highly in agreement with those obtained experimentally. All of the models above reproduce the trends of chemical shifts in all cases studied, suggesting that the models are of practical value.

Synthesis of ethoxycarbonyl isothiocyanate by orthogonal design

Using Schiff base as a phase transfer catalyst, ethoxycarbonyl isothiocyanate was synthesized by reacting ethyl chloroformate with sodium thiocyanate. In order to get the best synthetic technology, an orthogonal test （L9（34）） was applied. The results show that reaction temperature, reaction time, content of catalyst and molar ratio of sodium thiocyanate to ethyl chloroformate are the main factors influencing the yield. The four factors chosen for the present investigation are based on the results of a single-factor test. The optimum synthetic technology is determined as follows： reaction temperature 35 ℃, reaction time 3 h, the content of catalyst （molar fraction based on ethyl chloroformate） 1.5% and molar ratio of sodium thiocyanate to ethyl chloroformate 1.1. Under the optimized synthetic technology, the experimental yield reaches 96.8%.

Phase Transfer Catalysis: Oxidation of 2-Methyl-1-butanol

In liquid-liquid systems, the substrates in the liquids are inaccessible to each other for the reaction. By adding a small quantity of phase transfer catalyst, the reaction can be made accessible and accelerated. The present study involves the phase transfer catalyzed oxidation of 2-methyl-l-butanol by quaternary ammonium permanganate （tricaprylyl methyl ammonium permanganate）. The attempt was to compare the kinetics under homogeneous and heterogeneous conditions. Experiments were conducted in a batch reactor to determine the kinetics under homogeneous conditions. A baffled horosilicate agitated reactor was used to find the enhancement factor and the kinetics under heterogeneous conditions. The rate constants determined under both homogeneous and heterogeneous conditions agreed very weU. The oxidation was found to be first order with respect to each of the reactants, quaternary ammonium permanganate and the alcohol, resulting in an overall second order rate expression. Aliquat336 （tricaprylylmethylammonium chloride） was found to be the best compared with the other catalysts tested （triethylbenzylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium iodide and tetrabutylammonium hydrogen sulfate） and it gave an enhancement factor of 9.8.

Polymorphisms and functions of the aldose reductase gene 5' regulatory region in Chinese patients with type 2 diabetes mellitus

OBJECTIVE: To screen the 5' regulatory region of the aldose reductase (AR) gene for genetic variabilities causing changes in protein expression and affecting the promoter function. METHODS: The screenings were carried out by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP). All SSCP variants were submitted for DNA sequencing and inserted into the plasmid chloromycetin acetyl transferase (CAT) enhancer vector. The constructs were used to transfect Hela cells, and CAT assays were performed to assess promoter activity. Gel mobility shift and footprinting assays were also performed to determine the interaction between the DNA and nuclear proteins. RESULTS: Two polymorphisms, C (-106) T and C (-12) G, were identified in the regulatory region in 123 Chinese control subjects and 145 patients with type 2 diabetes mellitus. The frequencies of genotypes WT/WT, WT/C (-12) G and WT/C (-106) T were not significantly different between the subjects and patients. In the patients with and without retinopathy, frequencies of WT/C (-106) T were 31.5% and 17.5% (P 0.05) respectively. The total frequency of WT/C (-12) G and WT/C (-106) T in patients with retinopathy was 41.8%, significantly higher than that (20.0%) in patients without retinopathy (P

Comparison of the effects of carbamyl-β-methylcholine chloride ad ministered by intravenous,intramuscular and intra-acupuncture point injections

OBJECTIVE:To compare the effects of carbamylβ-methylcholine chloride(CMCC) administered by intra-acupuncture point injection(IAI),intramuscular injection(IMI),and intravenous injection(IVI),and to analyze the mechanisms.METHODS:In the IAI group,CMCC was injected into the Zusanli acupoint(ST 36) immediately after 30-min stimulation by electro-acupuncture(EA) at the acupoints,and into the femoral vein and skeletal muscle in IVI and IMI groups,respectively.Intra-gastric pressure was detected.The plasma concentration of CMCC was measured at various times.RESULTS:The gastric effect of CMCC in the IVI group was enhanced and attenuated more rapidly than in the other groups.In the IAI group,this effect was significantly stronger than that in the IMI group at 2 min and 15 min,but not significantly different between the two groups at 5 min and 30 min.Plasma concentration of CMCC in the IAI group was similar to that in the IVI group at 2 min,but higher than that in the IMI group.The concentration in the IAI group was higher than that in the IV group and similar to that in the IMI group at 5,15 and 30 min,indicating rapid increase and slower reduction of the plasma concentration of the drug in the IAI group.There was a positive correlation between the plasma concentration of CMCC and intragastric pressure in all groups.CONCLUSION:The effect of IAI with CMCC was stronger than that of IMI and longer-lasting than that of IVI,which correlated with the blood concentration of CMCC.

Polymorphisms and functions of the aldose reductase gene 5' regulatory region in Chinese patients with type 2 diabetes mellitus

Objective To screen the 5’ regulatory region of the aldose reductase (AR) gene for genetic variabilities causing changes in protein expression and affecting the promoter function. Methods The screenings were carried out by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP). All SSCP variants were submitted for DNA sequencing and inserted into the plasmid chloromycetin acetyl transferase (CAT) enhancer vector. The constructs were used to transfect Hela cells,and CAT assays were performed to assess promoter activity. Gel mobility shift and footprinting assays were also performed to determine the interaction between the DNA and nuclear proteins. Results Two polymorphisms, C(-106)T and C(-12)G, were identified in the regulatory region in 123 Chinese control subjects and 145 patients with type 2 diabetes mellitus. The frequencies of genotypes WT/WT, WT/C(-12)G and WT/C(-106)T were not significantly different between the subjects and patients. In the patients with and without retinopathy, frequencies of WT/C(-106)T were 31.5% and 17.5% (P【0.05) respectively, and the frequencies of WT/C(-12)G were 10.5% and 2.5% (P】0.05) respectively. The total frequency of WT/C(-12)G and WT/C(-106)T in patients with retinopathy was 41.8%, significantly higher than that (20.0%) in patients without retinopathy (P【0.025). The relative transcription activities of the wild-type, the C(-12)G and the C(-106)T were 15.7%, 31.0% and 32.2%, respectively. The results of DNA-protein interaction assays showed that these variations did not change the binding site of DNA with trans-acting factors. Conclusion The polymorphisms C(-12)G and C(-106)T strongly associated with diabetic retinopathy in the Chinese population have been identified in the regulatory region of the aldose reductase gene.

Effect of ground granulated blast-furnace slag(GGBFS) and silica fume(SF) on chloride migration through concrete subjected to repeated loading

The effect of ground granulated blast-furnace slag(GGBFS) and silica fume(SF) on the chloride migration through concrete subjected to repeated loading was examined.Portland cement was replaced by 20%,30%,40% GGBFS and 5%,10% SF,respectively.Five times repeated loadings were applied to specimens,the maximum loadings were 40% and 80% of the axial cylinder compressive strength(f′c),respectively.Chloride migration through concretes was evaluated using the rapid chloride migration test and the chloride concentration in the anode chamber was measured.The results indicate that the transport number of chloride through concrete containing 20% and 30% GGBFS replacements and 5% and 10% SF replacements is lower than that of the control concrete,but 40% GGBFS replacement increases the transport number of chloride.Five loadings at 40% f′cor 80% f′c increase the transport number of chloride for all mixes investigated in this study.5% SF replacement has a very close effect on the chloride permeability of concrete with 20% GGBFS when concrete is subjected to 40% f′cor 80% f′c.

Effects of P3HT concentration on the performance of organic field effect transistors

Top-contact organic field effect transistors(OFETs) based on poly(3-hexylthiophene)(P3HT) with different concentrations in chloroform(CHCl3) are fabricated.The output characteristics indicate that the P3HT concentration has significant influence on the OFET devices.The performance of the devices firstly is enhanced with increasing the P3HT concentration,and then decreases.The optimized devices with the P3HT concentration of 2 mg/mL show the best performance.The fieldeffect mobility is up to 1.4×10-2 cm2/Vs,the threshold voltage(Vt) is as low as-20 V,and the current on/off ratio(Ion/off) is close to the order of 104.The results suggest that the P3HT aggregation patterns induced by different concentrations can improve the performance of the OFETs.

HSV-1 stimulation-related protein HSRG1 inhibits viral gene transcriptional elongation by interacting with Cyclin T2

The protein encoded by HSRG1(HSV-1 stimulation-related gene 1) is a virally induced protein expressed in HSV-1-infected cells.We have already reported that HSRG1 is capable of interacting with transcriptional regulator proteins.To further analyze the effects of HSRG1 on the regulation of viral gene transcription,we expressed the HSRG1 protein in transfected cells and found that it postpones the proliferation of HSV-1.CAT(chloramphenicol acetyltransferase) assays also revealed that HSRG1 reduces transcription from HSV-1 promoters.Yeast two-hybrid and immunoprecipitation assays indicated that HSRG1 interacts with Cyclin T2,the regulatory subunit of P-TEFb,which is required for transcription elongation by RNA Pol II(RNAP II) ,and that amino acid residues 1-420 in Cyclin T2 are important for binding with HSRG1.Fluorescence assays suggested that the cellular localizations of those two proteins are influenced by their interaction.Further analyses with CAT assays revealed that HSRG1 inhibits the transcriptional activation by Cyclin T2 of viral promoters.Our results suggested that the inhibitory effects of HSRG1 on viral replication and proliferation are probably induced by its binding to Cyclin T2.Therefore,it is likely that HSRG1 inhibits viral gene transcriptional elongation by interacting with Cyclin T2.

Electro-acupuncture on the iNOS of Lumbar lntervertebral Disk Tissues in Rats

Objective： The present study is to investigate the mechanism of dectrtyacupuncture in preventing and treating lumbar intervertebral disk displacement. Methods： Seventy-five Sprauge-Dawley rats were used to establish the models of lumbar intervertebral disk displacement by operation, and divided into five groups including electro-acupuncture group, western medicine group, acupuncture plus medicine group, model group and normal control group, then they were treated with corresponding therapeutic method. The expression of inducible nitric oxide synthase （iNOS） mRNA in the lumbar intervertebral disk tissues of rats was detected by RTPCR. Results： The expression of iNOS mRNA in the lumbar intervertebral disk tissues of rats in model group was compared with that in normal control group, the significant difference was found （P〈 0.01）; While the expressions of iNOS mRNA in the lumbar intervertebral disk tissues of rats in electroacupuncture group, western drug group and acupuncture plus medicine group were all inhibited, and compared with the model group, the significant differences were also found （P 〈 0.01）. Conclusion： Electro-acupuncture could inhibit the expression of iNOS mRNA in the lumbar intervertebral disk tissue.