Simultaneous Determination of Amphiphobicities of Material Surface by A Dual-Indicator Headspace Gas Chromatography.

This paper reports on a new method for simultaneously determining the amphiphobicities of material surface by a dual-indicator assisted headspace gas chromatography. After adding 40 µL of both methanol-water and toluene-oil droplets on the sample surface for 20 s, the sample was turned vertically (to remove water and oil) and then placed in a headspace vial. The amount of methanol and toluene in the residual water and oil adhered to material surface was quantified using headspace gas chromatography. The results showed that the method has good measurement precision (RSD < 4.58%). It can be an effective tool for simultaneously determining the amphiphobicities of material surface.

[Biological characteristics of bacteriophages infecting three typic rhizobia of legume]. / 侵染3æ ªæ¨¡å¼è±†ç§‘æ ¹ç˜¤èŒçš„å™¬èŒä½“ç”Ÿç‰©å­¦ç‰¹æ€§.

Bacteriophages infecting rhizobia of legume leads to a significant decrease in the number of rhizobia in soil and nodulation in legume, which finally affects nitrogen fixation and remarkably reduces crop yield. However, limited studies have focused on bacteriophages of rhizobia. In this study, three typic rhizobium strains of Bradyrhizobium diazoefficiens USDA110T, Sinorhizobium sojae CCBAU05684T and Sinorhizobium meliloti USDA1002T were used as the host bacteria. From each host, three rhizobiophages were isolated from an agricultural black soil with double-layer plate method. We isolated nine rhizobiophages and investigated their morphological feature and biological characteristics. The results showed that the phages of SMM (infecting Sinorhizobium meliloti USDA1002T) and BDM (infecting Bradyrhizobium diazoefficiens USDA110T) belonged to Myoviridae family, while phages of SSS (infecting Sinorhizobium sojae CCBAU05684T) belonged to Siphoviridae family. The optimal multiplicity of infection for nine phages ranged from 0.001 to 1.0. The one-step growth curve showed that the latent and rising periods of BDM were remarkably longer than that of SMM and SSS, but the bust size was minimal. Nine phages had the strongest infecting activity at 30-40 ℃ and at neutral pH condition. Comparative analysis showed that the biological characteristics of phages infected with the same host were different, with the differentiation being smaller than that of phages infected with different hosts.

Determination of starch gelatinization temperatures by an automated headspace gas chromatography.

This paper reports on an automated temperature-programmed headspace GC technique for the determination of gelatinization temperature of starch. 1-butanol was used as a tracer and added to the starch-solution for the test. Based on measuring the GC signal of 1-butanol in the headspace with the temperature increasing, two transition points (corresponding to the onset temperature and the ending temperature of starch gelatinization) were observed by plotting the GC signal of 1-butanol vs. the temperature. The results showed that the method has a good measurement precision (the standard deviation < 1 °C) and accuracy (the average relative differences = 3.9%, compared to a standard reference method). The present method is simple and suitable for the gelatinization temperature testing for starch samples.

Determination of the softening point of rosin by a simple and automated headspace gas chromatographic technique.

We report a simple and automated headspace gas chromatographic technique for the determination of the softening point of rosin. A lumpy solid of rosin is added into a headspace vial, then an automated stepwise temperature ramping and headspace sampling was performed at each temperature stage and gas chromatography measurement. By plotting the gas chromatography signal for an impurity in rosin versus the temperature, a transition point (corresponding to the rosin softening point) was determined. The results show that the present method has a good precision (<0.76%), and good accuracy (the relative differences compared to the ring and ball method was <4.0%). The present method is simple, accurate, and automated. It is practical and suitable for testing the softening of rosin and derivatives in mills.

A pressure-affected headspace-gas chromatography method for determining calcium carbonate content in paper sample.

The present work reports on the development of a pressure-affected based headspace (HS) analytical technique for the determination of calcium carbonate content in paper samples. By the acidification, the carbonate in the sample was converted to CO2 and released into the headspace of a closed vial and then measured by gas chromatography (GC). When the amount of carbonate in the sample is significant, the pressure created by the CO2 affects the accuracy of the method. However, the pressure also causes a change in the O2 signal in the HS-GC measurement, which is a change that can be used as an indirect measure of the carbonate in the sample. The results show that the present method has a good precision (the relative standard deviation<2.32%), and good accuracy (the relative differences compared to a reference method was<5.76%). Coupled with the fact that the method is simple, rapid, and accurate, it is suitable for a variety of applications that call for the analysis of high carbonate content in paper samples.

Three new biphenyls from the twigs of Garcinia tetralata and their anti-tobacco mosaic virus activity.

Phytochemical investigations on the ethanol extract of the twigs of Garcinia tetralata resulted in the isolation of three new biphenyls, tetralatabiphenyls A-C (1-3), along with three known biphenyl derivatives (4-6). Structural elucidations of 1-3 were performed by spectroscopic methods such as 1D and 2D NMR spectra, in addition to high-resolution mass spectra. Compounds 1-6 were also evaluated for their anti-tobacco mosaic virus (anti-TMV) activity. The results showed that compound 3 showed high anti-TMV activity with inhibition rate of 31.1%. Compounds 1, 2, and 4-6 also showed modest anti-TMV activities with inhibition rates in the range of 18.9-24.5%, respectively.

[Effects of manure application on the diversity of corn root endophytic bacterial communities at seedling stage in eroded Mollisols.] / æ–½ç”¨æœ‰æœºè‚¥å¯¹ä¾µèš€é»‘åœŸçŽ‰ç±³è‹—æœŸæ ¹å† ç”Ÿç»†èŒå¤šæ ·æ€§çš„å½±å“.

In order to investigate the change of root endophytic bacterial communities under soil erosion condition, and to evaluate the response of root endophytic bacteria to manure fertilizer, we adopted the LNA-PCR clamping and 454 bar-coded pyrosequencing methods to study the corn root endophytic bacterial communities under 30 cm topsoil erosion and manure fertilization conditions. No topsoil removing (0 cm) and only chemical fertilizer treatment were used as control. A total of 37820 valid sequences of 16S rDNA were obtained, mainly distributed in 4 phyla, 35 classes, 214 genera and 782 OTUs. The dominant phyla were Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes, but their proportions varied in different samples. The diversity of corn root endophytic bacteria decreased in soil erosion condition. In the topsoil removing soil and no erosion soil, the diversity of corn root endophytic bacterial communities increased by manure application, and the effect was more obvious in the topsoil removing soil.

[Dipylidium caninum infection in an infant: one case report].

This paper reports the diagnosis and therapy of one case of Dipylidium caninum infection in an infant.

[Therapeutic effect of 138 imported falciparum malaria patients].

OBJECTIVES: To summarize the clinical characteristics of imported falciparum malaria patients and the treatment, so as to provide the evidences for improving the diagnosis and treatment of the disease. METHODS: A total of 138 imported falciparum malaria patients who received the treatment in Shandong Institute of Parasitic Diseases from January 2007 to February 2013 were adopted as the observation subjects, and their clinical data were collected and analyzed. RESULTS: All the 138 patients were back from African countries. The main manifestations were fever, headache, asthenia, and hepatosplenomegaly, and most of them were with decreased RBC, PLT levels and increased LDH levels, and 36.96% of them were misdiagnosed as respiratory diseases, nephritis, hepatitis and so on. Through antimalarial treatment of artemether or artesunate or dihydroartemisinin and primaquine, or dihydroartemisinin and piperaquine, and symptomatic treatment, the short-term and long-term cure rates were 98.55% and 94.93% respectively, with 1 case unrecovered and 1 died. CONCLUSIONS: Artemisinins are still the most effective antimalarial drugs for falciparum malaria. However, some patients recrudesce as the Plasmodium in their body is resistant or insensitive to these drugs. We should pay more attention to the antimalarial and symptomatic treatments in the early stage of severe malaria so as to improve the cure rate.

[Technique of running urethrovesical anastomosis during radical laparoscopic prostatectomy: separate application of two needles].

OBJECTIVE: To study the value and feasibility of a novel method of urethrovesical anastomosis during radical laparoscopic prostatectomy. METHODS: From 2008 to 2009, 10 patients with local prostate cancer (LPC) underwent radical laparoscopic prostatectomy through the placement of two separate needles for running urethrovesical anastomosis. The first step comprised the first stitch placed in the posterior wall of anastomosis (at 4 o'clock) and then clockwise running suture from 4 to 12 o'clock position. The next steps entailed another needle, stitching at 3 o'clock position and counterclockwise running suture. Two sutures would meet at 12 o'clock position for the third and final knot. When the position of urinary leak was observed, an additional suture would be performed. RESULTS: This technique was performed in 10 patients with a mean anastomosis duration of 30 minutes (range: 25 - 45) and a mean operative duration of 220 minutes (range: 200 - 300). The Foley catheter was implanted for 14 days. Neither bladder neck stricture nor urinary leak was observed with a follow-up period of 3 - 24 months. CONCLUSIONS: The described technique is a feasible and safe method for urethrovesical anastomosis with a low rate of complications. And it may be quickly mastered so as to lower the learning curve of a novice.

[Simultaneous determination of multi-organotin compounds in seawater by liquid-liquid extraction-high performance liquid chromatography-inductively coupled plasma mass spectrometry].

The hyphenated technique of high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry (HPLC-ICP-MS) was applied to the simultaneous determination of five organotin compounds (trimethyltin, dibutyltin, tributyltin, diphenyltin and triphenyltin) in seawater samples. Agilent TC-C18 column was used for the separation, the mobile phase of HPLC was CH3CN : H2O : CH3COOH = 65 : 23 : 12 (phi3), 0.05% TEA, and pH value was adjusted to 3.0 by diluent ammonia. The flow rate was 0.6 mL x min(-1). Five mixed organotin compounds in a mix standard solution from 100 to 0.5 microg x L(-1) were applied for the method assessment. The experimental results indicate that the correlation coefficient of calibration curves (R2) for each organotin compound was over 0.998 and the detection limits of the five organotin compounds were lower than 3 ng x L(-1). Different mixed organic solvents including dichloromethane or toluene were used for extraction of organotin and the extraction condition of organotin from seawater was optimized. The 100 mL seawater acidized by hydrochloric acid was extracted by 10 mL carbon dichloride (CH2 Cl2) with 2% tropolone for 10 min twice. Extracted organic solvents were mixed and blown to one drop by nitrogen with the rate of 1.7 mL x min(-1), then 1 mL acetonitrile was added to the drop for redissolving the organotin compounds. Finally, the mixed redissolution was filtered by 0.22 microm organic filter membrane before analysis. It was found that the only organotin compound in seawater was triphenyltin (TPHT) and the content was 53.2 ng x L(-1). The recoveries test from the standard addition for diphenyltin (DPHT), dibutyltin (DBT), tributyltin (TBT) and triphenyltin (TPHT) were over 80%. However, the recovery for trimethyltin (TMT) was relatively low and the value was 50%. The reason might be attributed to the decomposition or adsorption of those compounds during the extraction procedure. Further study on this subject is in progress.

[Application of EITB in immunodiagnosis of cysticercosis].

OBJECTIVE: To establish a sensitive and specific method EITB for the immunodiagnosis of cysticercosis. METHODS: Two-dimensional electrophoresis was used to analyze and purify the cyst fluid antigen. Western blotting using the sera of patients with cysticercosis, hydatidosis, and other heteroserum was used to screen the specific antigens. EITB using the specific antigen was established and compared with ELISA. The detection effect of serum and blood on filter paper in EITB was also compared. RESULTS: Two specific antigens with isoelectric point (pI) of 9.4 and Mr of 14000 and 16600 were obtained, respectively. EITB method based on these antigens was established with the sensitivity and specificity of 92.5% and 100%, respectively, significantly higher than that of ELISA. The sensitivity of serum and filter paper blood was similar in EITB. CONCLUSION: A sensitive and specific EITB method for immunodiagnosis of cysticercosis was established.