Repair of buccal mucosa and floor of mouth defects using keystone design perforator island flap.

OBJECTIVE: To assess the feasibility of utilizing the keystone design perforator island flap (KDPIF) for the repair of small to medium-sized defects in the buccal mucosa and floor of mouth (cT1-2 stage tumor). STUDY DESIGN: We conducted a retrospective analysis of eight patients who underwent KDPIF to address oral defects at the Affiliated Hospital of Qingdao University between June 2021 and September 2022. Patient information, including medical history, defect site, flap size, operative time, hospital stay, complications, and postoperative recovery of oral function, was comprehensively evaluated. RESULTS: Eight patients (6 females and 2 males) underwent reconstruction using KDPIF. The mean operation time was 58.5 minutes (55-63 minutes), with an average length of stay of 3.5 days (3-5 days). None of the 8 cases (100%) exhibited flap splitting necrosis or infection. Moreover, no scar contracture was observed, and oral functions, including the degree of opening, type of opening, tongue mobility, speech function, and swallowing function, were successfully restored. One patient (12.5%) experienced bleeding from the incision on the first postoperative day, but following compression, hemostasis was achieved, and the incision healed well. CONCLUSIONS: KDPIF demonstrates technical feasibility and suitability for repairing small to medium-sized buccal mucosa and floor of mouth defects (cT1-2).

A review of smart agriculture and production practices in Japanese large-scale rice farming.

Japanese farms currently occur on a small but expanding average physical scale and annual sales, in a decreasing and aging labor force, increasingly abandoned farmland and massive access of corporations powerful in capital and management. The government has proposed to accelerate agricultural growth through adopting high-level smart technologies in large-scale farms, with a series of favorite policies and measures. This paper reviews the connotations, characteristics and technologies of smart agriculture in the views of Japanese scholars, the practice of smart agriculture in Japan, followed by a case study on the smart rice production model 'NoshoNavi1000'. The results show that Japanese scholars have conducted in-depth and massive studies in smart agriculture, with regional characteristics in the orientations on labor-saving, precise management, disaster reduction and inheriting traditional farming skills. The government's ambitious objective is supported by its all-round policy package, including project demonstration, supporting services, environmental improvement, education and training, and overseas outreaching. Closely combined with the planting structure of Japanese agriculture, rice production is an important sector for the R&D and application of smart farming in the form of either individual technologies or models. The policies and technologies have achieved benefits in saving labor and production costs, and improving the profit margin. Through years of on-farm application, 'NoshoNavi1000' has been developed to involve the major technological components of smart agriculture. It has contributed to improving rice yield, production efficiency and profitability of large-scale farms, through real-time data collection, comprehensive and professional data mining, and specific and practical feedbacks. © 2022 Society of Chemical Industry.

Evaluation of Common Prosperity Level and Regional Difference Analysis along the Yangtze River Economic Belt.

Common prosperity is the essential requirement of socialism as well as the common aspiration of social people. This article constructed an evaluation index system of 25 indicators for common prosperity, covering four dimensions of material wealth, harmonious social life, rich spiritual life, and livable ecological environment. The TOPSIS method was used to comprehensively rank nine provinces and two municipalities in the Yangtze River Economic Belt. The results show that the level of common prosperity along the Yangtze River Economic Belt increased significantly from 2010 to 2019, and the level of common prosperity in the lower reaches of the Yangtze River Economic Belt is much higher than that in the middle and upper reaches. According to the differences in common prosperity levels among regions, provinces and cities are divided into three categories: high, unbalanced, and low. Combined with the characteristics of each type of region, policy suggestions were put forward from the perspectives of strengthening the regional industrial cooperation mechanism, deepening the construction of regional livelihood infrastructure and basic public services, and improving the ability of regional environmental coordination.

Effects of combined nitrification inhibitors on soil nitrification, maize yield and nitrogen use efficiency in three agricultural soils.

Application of nitrification inhibitors (NIs) with nitrogen (N) fertilizer is one of the most efficient ways to improve nitrogen use efficiency (NUE). To fully understand the efficiency of NIs with N fertilizer on soil nitrification, yield and NUE of maize (Zea mays L.), an outdoor pot experiment with different NIs in three soils with different pH was conducted. Five treatments were established: no fertilizer (Control); ammonium sulfate (AS); ammonium sulfate + 3, 4-dimethyl-pyrazolate phosphate (DMPP) (AD); ammonium sulfate + nitrogen protectant (N-GD) (AN); ammonium sulfate + 3, 4-dimethyl-pyrazolate phosphate + nitrogen protectant (ADN). The results showed that NIs treatments (AD, AN and ADN) significantly reduced soil nitrification in the brown and red soil, especially in AD and ADN, which decreased apparent nitrification rate by 28% - 44% (P < 0.05). All NIs treatments significantly increased yield and NUE of maize in three soils, especially ADN in the cinnamon soil and AD in the red soil were more efficiency, which significantly increased maize yield and apparent nitrogen recovery by 5.07 and 6.81 times, 4.39 and 8.16 times, respectively. No significant difference on maize yield was found in the brown soil, but AN significantly increased apparent nitrogen recovery by 70%. Given that the effect of NIs on both soil nitrification and NUE of maize, DMPP+N-GD was more efficient in the cinnamon soil, while N-GD and DMPP was the most efficiency in the brown and red soil, respectively. In addition, soil pH and soil organic matter play important role in the efficiency of NIs.

Effects of different nitrification inhibitors on nitrification, maize yield, and nitrogen use efficiency in red soil.

We examined the effects of nitrification inhibitors (NIs) on soil nitrification, maize yield and nitrogen use efficiency (NUE), aiming to screen out high efficiency stabilized ammonium chloride fertilizer in red soil. Nitrification inhibitors 2-chloro-6-trimethyl-pyridine (CP), 3, 4-dimethyl-pyrazolate phosphate (DMPP), and dicyandiamide (DCD) and their combinations were added into ammonium chloride (NH4Cl) to make six stabilized nitrogen fertilizers. With blank (CK) and NH4Cl (N) as the controls, we conducted a maize pot experiment with the same amount of nitrogen addition. The results showed that compared with the treatment of N, soil ammonium content in CP+DMPP and DMPP+DCD increased by 56%-62%, which was significantly higher than that in CP, DMPP, and DCD, while the apparent nitrification rate of red soil was significantly reduced by 33%-34%. All the six treatments with nitrification inhibitors and their combinations significantly improved biomass and nitrogen absorption efficiency of maize. Compared with the N treatment, the application of adding NIs alone was significantly higher than that of the treatments of NIs combinations, with an average of 1.3 times increase. DCD was the most efficient one in improving maize yield, nitrogen uptake, and nitrogen adsorption efficiency, which increased by 4.1, 6.3 and 4.4 times, respectively. Comprehensively, DCD performed the best in reducing cost and improving yield and nitrogen use efficiency in red soil.

[Application effect of high efficiency and stability urea added with biochemical inhibitors and humic acid in loess]. / æ·»åŠ ç”ŸåŒ–æŠ‘åˆ¶å‰‚å’Œè æ¤é ¸çš„ç¨³å®šæ€§å¢žæ•ˆå°¿ç´ åœ¨é»„åœŸä¸­çš„æ–½ç”¨æ•ˆæžœ.

We carried out pot experiment to investigate nitrogen transformation characteristics, yield increasing effect, and apparent utilization rate of nitrogen fertilizer in loess soils by combining chemi-cal inhibitor and biostimulant humic acid to investigate the application effect and provide a theoretical basis for new type highly efficient and stable urea in loess soil. In this study, blank (CK) and urea (N) were set as controls, and humic acid alone (F), N-butyl thiophosphate-triamine (NBPT), 3,4-dimethyl-pyrazolate phosphate (DMPP), 2-chloro-6-trimethyl-pyridine (CP) and humic acid were respectively combined with three biochemical inhibitors to urea. The results showed that compared with N treatment, F, NBPT+F, DMPP+F, CP+F treatments significantly increased maize yield, chlorophyll content, leaf area index and nitrogen uptake, and had obvious effects on soil available nitrogen contents. The addition of humic acid increased chlorophyll content of maize leaves in all cases compared to the application of biochemical inhibitors alone. Compared with CP treatment, CP+F treatment could significantly increase nitrogen uptake, chlorophyll content, and nitrogen adsorption efficiency of maize. Addition of humic acid with NBPT increased nitrification inhibition rate by 10.7% compared with NBPT alone, but decreased yield, leaf area index, nitrogen uptake, nitrogen use efficiency. Compared with DMPP treatment, DMPP+F treatment significantly reduced maize yield, leaf area index, nitrogen uptake, nitrogen use efficiency and nitrification inhibition rate. Considering maize yield, plant N uptake, N fertilizer uptake rate and soil ammonium N and nitrate N contents, the addition of humic acid and CP is recommended for urea application in loess areas to enhance urea performance, yield, and fertilizer utilization.

[Effect of urease/nitrification inhibitor on urea nitrogen conversion in black soil and cinnamon soil.] / è„²é ¶/ç¡åŒ–æŠ‘åˆ¶å‰‚åœ¨é»‘åœŸå’Œè¤åœŸä¸­å¯¹å°¿ç´ æ°®è½¬åŒ–çš„è°ƒæŽ§æ•ˆæžœ.

We studied the effects of urease/nitrification inhibitor combinations on urea hydrolysis and nitrification, aiming to screen out the effective inhibitor combinations for black soil and cinnamon soil in Northeast China. Urease inhibitor, N-butyl thiophosphate-triamine (NBPT), and its combination with nitrification inhibitor dicyandiamide (DCD), 3, 4-dimethylpyrazole phosphate (DMPP), 2-chloro-6 (trichloromethyl)-pyridine (CP), 2-amino-4-chloro-6-methylpyrimidine (AM) and 3-methylpyrazole (MP) were added to urea separately. Samples were collected 15 times in each of all the treatments during 125 days. We examined the changes of urea nitrogen, ammo-nium, nitrate, and nitrification inhibition rate in the two soils. Our results showed the hydrolysis of urea in black soil and cinnamon soil was about 7 d, and the addition of NBPT with or without diffe-rent nitrification inhibitors slowed down the hydrolysis to 21 d at least. Compared with the treatment with common urea, inhibitor addition significantly increased soil NH4+-N, decreased soil NO3--N, and maintained the high NH4+-N content in soil for a longer time. In black soil, application with nitrification inhibitor inhibited soil nitrification significantly and lasted for more than 125 d. DMPP and CP combined with NBPT increased the NH4+-N content in black soil by 1.6-1.8 times, while the nitrification inhibition rate was 47.9% and 24.1% at 125 d, respectively. In the cinnamon soil, the application of nitrification inhibitor could prolong the duration of ammonium oxidation from 80 d to 110 d. DCD and DMPP combined with NBPT increased the NH4+-N content in cinnamon soil by 2.1-3.4 times, while the nitrification inhibition rates at 125 d were 25.3% and 23.2%, respectively. Therefore, NBPT+DMPP combination with urea was recommended for utilization in black soil, followed by NBPT+CP. In cinnamon soil, NBPT+DCD combination with urea was recommended, followed by NBPT+DMPP.

Effect of straw and inhibitors on the fate of nitrogen applied to paddy soil.

A pot experiment was used to explore the distribution of fertilizer N and agronomic effects in a paddy soil-rice (Oryza sativa L.) system. Five treatments were set: without nitrogen, straw and inhibitor (C), urea (U), urea + straw (US), urea + urease + nitrification inhibitor (UI) and urea + urease + nitrification inhibitor + straw (UIS). Soil and urea-derived microbial biomass N increased significantly in US and UIS compared with straw-free treatments at seedling and tillering, indicating that biotic process play an important role in the retention of fertilizer N with straw addition. About 10% urea-N was recovered as fixed ammonium (FA) at seedling stage, subsequently released at tillering and maturation regardless of treatments, which emphasizes the importance of FA in the retention and supply of fertilizer N in paddy soils. Compared with U, rice yield and N uptake in US decreased by 7.8% and 25.2% respectively, while inhibitors (UIS) alleviated the reduction by 16.4% and 31.6%. The current research indicated UIS is recommended as the most appropriate management strategy in paddy soils of Northeast China based on N dynamics. But the economic effect as well as the field-scale validation need to be further evaluated.

[Effects of high efficiency and stability ammonium sulfate fertilizer applied in black soil]. / é«˜æ•ˆç¨³å®šæ€§ç¡«é ¸é“µæ°®è‚¥åœ¨é»‘åœŸä¸­çš„æ–½ç”¨æ•ˆæžœ.

To develop high efficiency stabilized N fertilizer, a pot experiment was conducted to examine the effects of stabilized ammonium sulfate with different nitrification inhibitors on soil avai-lable nitrogen (N) contents, nitrification inhibition rate, apparent nitrification rate, yield, some agronomic parameters and N fertilizer utilization rate of corn in black soil of Jilin Provinve. In this study, blank (CK) and (NH4)2SO4 (N) were set as controls, and nitrification inhibitor 3,4-dimethyl-pyrazolate phosphate (DMPP), 2-chloro-6-trimethyl-pyridine (CP), ammonia protectant N-GD and nitrogen fertilizer synergist HFJ and their combination applied to ammonium sulfate to form nine treatments. The results showed that compared with the treatment of N, application of DMPP and its combinations in black soil significantly affected soil available N contents and the apparent nitrification rate. The contents of ammonium increased by 1.4-2.0 times, while the contents of nitrate and the apparent nitrification rate of soil decreased by 13.6%-17.9% and 55.3%-59.8%, respectively. DMPP, DMPP+HFJ, DMPP+N-GD had the highest nitrification inhibition rate, which reached higher than 16.5%. DMPP+HFJ+N-GD and HFJ increased the chlorophyll content in maize leaves by 4.5-5.3 times. The addition of nitrification inhibitors and fertilizer synergist to ammonium sulfate did not affect plant height. Compared with the treatment of N, HFJ increased corn biomass, grain yield, economic coefficient, harvest index, agronomic utilization rate of fertilizer, N uptake utilization rate, fertilizer contribution rate and N partial productivity of corn by 1.2, 2.5, 0.7, 0.6, 2.7, 2.1, 1.3 and 2.5 times, respectively. In general, HFJ, DMPP, DMPP+HFJ, DMPP+N-GD performed best in black soil. By considering both the cost and N utilization rate, N fertilizer synergist HFJ is the first choice for stable ammonium sulfate N fertilizer biochemical inhibitor, followed by DMPP+HFJ or DMPP+N-GD.

[Effects of inhibitors and pig manure on the transformation of urea nitrogen in paddy soil].

With the aim to understand the response of different nitrogen forms in paddy soil under the conditions of urea combined with inhibitors and pig manure, and to explore the nitrogen retention and supply capacity of paddy soil under different management strategy, we conducted a pot experiment with 15N labeled urea. There were six treatments: no nitrogen fertilizer (CK), pig manure (M), urea (N), urea+pig manure (NM), urea+inhibitor (NI), urea+inhibitor+pig manure (NIM). Urease inhibitor (PPD+NBPT) and nitrification inhibitor (DMPP) were used as the inhibitor combination. Soil nitrogen pools, conservation of 15N labeled urea, and rice N adsorption were measured in rice seedling, tillering, and mature stages. Results showed that pig manure significantly increased soil ammonium concentration, soil microbial biomass nitrogen and fixed ammonium, as well as the storage of urea nitrogen in various pools at tillering stage, and significantly increased rice yield. Addition of the inhibitors increased NH4+ fixation by clay minerals and nitrogen immobilization by microorganisms compared with treatment N, and increased urea-derived NH4+ fixation by clay minerals compared with treatment NM. Pathway analysis showed that pig manure increased urea-N assimilation and yield of rice. The urea-derived ammonium fixed by clay minerals was temporarily stored after inhibitors application. NIM treatment stored more N in microbial biomass, and the released ammonium coupled the turnover and mineralization of microbial provided more available nitrogen for the later growth of rice. Both NM and NIM treatments are recommended in paddy fields of north China.

Simultaneous determination of ten bioactive constituents of Sanjie Zhentong Capsule in rat plasma by ultra-high-performance liquid chromatography tandem mass spectrometry and its application to a pharmacokinetic study.

Sanjie Zhentong capsule, a well-known traditional Chinese medicine prescription, are used for the treatment of endometriosis-related diseases. In this study, a simple, rapid and sensitive ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed for the simultaneous determination of ten bioactive constituents, including peimine, peiminine, peimisine, loureirin A, loureirin B, 7,4'-dihydroxyflavone, pterostilbene, ginsenoside Rg1, ginsenoside Rb1, and notoginsenoside R1 in rat plasma after oral administration of Sanjie Zhentong capsule. The sample preparations for protein removal was accomplished using a simple methanol precipitation method. The analytes were completely separated from the endogenous compounds on an Agilent Poroshell 120 SB-C18 column (4.6mm×150mm, 2.7µm) using an isocratic elution with methanol - 0.1% formic acid aqueous (4/1, v/v) as a mobile phase. The single-run analysis time was as short as 14.0min. The inter-day and intra-day precision of the quality control samples exhibited relative standard deviations (RSD) <9.5% and the accuracy values ranged from -8.6% to 15.0%. The lower limits of quantification (LLOQ) were 10, 10, 10, 10, 10, 10, 5, 10, 10 and 20ng/mL for peimine, peiminine, peimisine, loureirin A, loureirin B, 7,4'-dihydroxyflavone, pterostilbene, ginsenoside Rg1, ginsenoside Rb1, notoginsenoside R1, respectively. The analytical method was successfully applied to a pharmacokinetic study of the multi-components after oral administration of Sanjie Zhentong Capsule in rats.

Nitrogen Fertilizer and Straw Applications Affect Uptake of 13C,15N-Glycine by Soil Microorganisms in Wheat Growth Stages.

This study investigated the influence of nitrogen (N) fertilizer and straw on intact amino acid N uptake by soil microorganisms and the relationship between amino acid turnover and soil properties during the wheat growing season. A wheat pot experiment was carried out with three treatments: control (CK), N fertilizer (NF) and N fertilizer plus rice straw (NS). We used stable isotope compound-specific analysis to determine the uptake of 13C,15N-glycine by soil microorganisms. In the NF treatment, microbial 13C,15N-glycine uptake was lower compared with CK, suggesting that inorganic N was the preferred N source for soil microorganisms. However, The application of straw with N fertilizer (in NS treatment) increased microbial 13C,15N-glycine uptake even with the same amount of N fertilizer application. In this treatment, enzyme activities, soil microbial biomass C and microbial biomass N increased simultaneously because more C was available. Soil mineral N and plant N contents all decreased substantially. The increased uptake of intact 13C,15N-glycine in the NS treatment can be attributed to direct assimilation by soil microorganisms to satisfy the demand for N when inorganic N was consumed.

Simultaneous determination of 35 ultra-trace level organophosphorus pesticide residues in Sanjie Zhentong capsules of traditional Chinese medicine using ultra high performance liquid chromatography with tandem mass spectrometry.

The aim of this study was to develop an analytical method for the simultaneous determination of ultra-trace levels of 35 organophosphorus pesticide residues in Sanjie Zhentong capsules, a traditional Chinese medicine prescription. A method based on multiclass and multiresidue sample preparation was developed. First, samples were hydrated with water at 4°C. A ratio of 1:3 sample/water was used for each of the sample amounts. Then, different extraction solvents were screened. This step was followed by a dispersive solid-phase extraction clean-up procedure using both primary secondary amine and polyamide. A comprehensive sensitive multiresidue liquid chromatography tandem mass spectrometry method was investigated and validated. Good linearity was achieved in the range of 10-500 µg/kg for each analyte. The average recovery ranged from 70 to 120%, except for methamidophos, fonophos, diazinon, and chlorpyriphos-ethyl, the recoveries of which ranged from 60-70% at the lower concentration level. The precision values were lower than 10% for all the compounds in three concentration levels. The limits of detection and limits of quantification values were 0.01-2.1 and 0.05-3.4 µg/kg, respectively. The matrix effects were determined, and most of the compounds showed signal suppression. Finally, this optimized procedure was applied for the analysis of real samples.

Transporter-targeted cholic acid-cytarabine conjugates for improved oral absorption.

Cytarabine has a poor oral absorption due to its rapid deamination and poor membrane permeability. Bile acid transporters are highly expressed both in enterocytes and hepatocytes and to increase the oral bioavailability and investigate the potential application of cytarabine for liver cancers, a transporter- recognizing prodrug strategy was applied to design and synthesize four conjugates of cytarabine with cholic acid (CA), chenodeoxycholic acid (CDCA), hyodeoxycholic acid (HDCA) and ursodeoxycholic acid (UDCA). The anticancer activities against HepG2 cells were evaluated by MTT assay and the role of bile acid transporters during cellular transport was investigated in a competitive inhibition experiment. The in vitro and in vivo metabolic stabilities of these conjugates were studied in rat plasma and liver homogenates. Finally, an oral bioavailability study was conducted in rats. All the cholic acid-cytarabine conjugates (40µM) showed potent antiproliferative activities (up to 70%) against HepG2 cells after incubation for 48h. The addition of bile acids could markedly reduce the antitumor activities of these conjugates. The N(4)-ursodeoxycholic acid conjugate of cytarabine (compound 5) exhibited optimal stability (t1/2=90min) in vitro and a 3.9-fold prolonged half-life of cytarabine in vivo. More importantly, compound 5 increased the oral bioavailability 2-fold compared with cytarabine. The results of the present study suggest that the prodrug strategy based on the bile acid transporters is suitable for improving the oral absorption and the clinical application of cytarabine.

Simultaneous determination of ginkgolides A, B, C and bilobalide by LC-MS/MS and its application to a pharmacokinetic study in rats.

The study of pharmacokinetics of Ginkgo biloba extracts in Traditional Chinese Medicine was relatively recent. In this study, a simple, quick and sensitive LC-MS/MS analytical method was developed for the determination of ginkgolides A, B, C and bilobalide in rat plasma. The analytes were completely separated from the endogenous compounds on an Agilent Zorbax Eclipse plus C18 column (50 mm × 3.0 mm, 1.8 µm) using an isocratic elution. The single-run analysis time was as short as 5.0 min. Sample preparation for protein removal was accomplished used a simple methanol precipitation method, after SPE showing a simultaneous extraction and cleanup of extracts allowing for a direct analysis. Extraction recoveries in rat plasma for ginkgolides A, B, C and bilobalide ranged from 75.6% to 89.0%. The calibration curves were determined over the ranges 0.5-20,000 ng/mL for ginkgolides A, B, C and bilobalide respectively. The lower limits of quantification (LLOQ) of the analytes were 0.5 ng/mL. Inter-day and intra-day precision and accuracy were below 15% and between 85 and 115%, respectively. Finally, the developed method was successfully applied to a pharmacokinetic study following oral administration of the Ginkgo biloba extracts to the male ICR rats.

An HPLC-MS/MS method for simultaneous determination of decitabine and its valyl prodrug valdecitabine in rat plasma.

A simple and sensitive HPLC-MS/MS method was developed and validated for the simultaneous determination of decitabine and valdecitabine in rat plasma. The analytes were separated on a C(18) column (150mm×4.6mm, 3.5µm) and a triple-quadrupole mass spectrometer equipped with an electrospray ionization (ESI) source was applied for detection. A clean solid-phase extraction procedure with cation exchange cartridge was employed to extract the analytes from rat plasma with high recovery of decitabine (>82%). The calibration curves were linear over a concentration range of 10-10,000ng/mL for decitabine and 5-500ng/mL for valdecitabine. The lower limit of quantitation (LLOQ) of decitabine and valdecitabine was 10 and 5ng/mL, respectively. The intra-day and inter-day precisions were less than 15% and the relative error (RE) was all within ±15%. The validated method was successfully applied to a pharmacokinetics study in rats after either decitabine or valdecitabine orally administrated to the Sprague-Dawley rats.

Development of a supercritical fluid chromatography-tandem mass spectrometry method for the determination of azacitidine in rat plasma and its application to a bioavailability study.

Azacitidine is widely used for the treatment of myelodysplastic syndromes (MDS) and acute myelogenous leukaemia (AML). The analysis of azacitidine in biological samples is subject to interference by endogenous compounds. Previously reported high-performance liquid chromatography/tandem mass spectrometric (HPLC-MS/MS) bioanalytical assays for azacitidine suffer from expensive sample preparation procedures or from long separation times to achieve the required selectivity. Herein, supercritical fluid chromatography with tandem mass spectrometry (SFC-MS/MS) was explored as a more promising technique for the selective analysis of structure-like or chiral drugs in biological matrices. In this study, a simple, rapid and specific SFC/MS/MS analytical method was developed for the determination of azacitidine levels in rat plasma. Azacitidine was completely separated from the endogenous compounds on an ACQUITY UPLC™ BEH C18 column (100 mm×3.0 mm, 1.7 µm; Waters Corp., Milford, MA, USA) using isocratic elution with CO2/methanol as the mobile phase. The single-run analysis time was as short as 3.5 min. The sample preparation for protein removal was accomplished using a simple methanol precipitation method. The lower limit of quantification (LLOQ) of azacitidine was 20 ng/mL. The intra-day and inter-day precisions were less than 15%, and the relative error (RE) was within ±15% for the medium- and high-concentration quality control (QC) samples and within ±20% for the low-concentration QC samples. Finally, the developed method was successfully applied to a pharmacokinetic study in rats following the intravenous administration of azacitidine.

[Analysis of the character of film decomposition of starch acetate (SA) coated urea by infrared spectrum].

The degradability characteristics of film with 4 kinds of starch acetate coated and inhibitors amended urea were analyzed by FTIR, which was purposed to supply theoretical basis for applying starch acetate coated urea fertilizers in farming. The result showed that the chemical component, molecule structure and material form of the membrane were not changed because of adding different inhibitors to urea. The main peaks of the film degradation process were brought by the H--O, --OH, CO2, C==O, --CH2, --CH3, C--O, C--O--H and C--O--C vibrancy in asymmetry and symmetry. In brown soil, the trend of absorbing value of the most high peak was 0>15>30>60>90>120>150>310 d. The infrared spectra of 4 kinds of fertilizers were not different remarkably, and the film was comparatively slowly degraded before 15 d. But a majority of the film had been already degraded after 150 days. The main components of film materials were degraded fastest in 310 days. The speed of film degradation wasn't more impacted by different inhibitors. The characteristic of starch acetate film degradation may be monitored entirely and degradation speed difference of the film could be represented through infrared spectrum.

[Analysis of the character of film decomposition of methyl methacrylate (MMA) coated urea by infrared spectrum].

The degradability characteristics of film with 4 kinds of methyl methacrylate coated urea amended with inhibitors were analyzed by FITR, which was purposed to supply theoretical basis for applying the FITR analysis method to film decomposition and methyl methacrylate coated urea fertilizers on farming. The result showed that the chemical component, molecule structure and material form of the membrane were not changed because of adding different inhibitors to urea. the main peaks of expressing film degradation process were brought by the -C-H of CH3 & CH2, -OH, C-O, C-C, C-O-C, C=O, C=C flexing vibrancy in asymmetry and symmetry in 3 479-3 195, 2 993--2 873, 1 741-1 564, 1 461-925 and 850-650 cm(-1). The peak value changed from smooth to tip, and from width to narrow caused by chemical structural transform of film The infrared spectrum of 4 kinds of fertilizers was not different remarkably before 60 days, and the film was slowly degraded. But degradation of the film was expedited after 60 days, it was most quickened at 120 day, and the decomposition rate of film was decreased at 310 day. The substantiality change of film in main molecule structure of 4 kinds of fertilizers didn't happen in 310 days. The main component of film materials was degraded most slowly in brown soil. The speed of film degradation wasn't heavily impacted by different inhibitors. The characteristic of film degradation may be monitored entirely by infrared spectrum. The degradation dynamic, chemical structure change, degradation speed difference of the film could be represented through infrared spectrum.

[Analysis of soil humus and components after 26 years' fertilization by infrared spectroscopy method].

The infrared spectrum was used to discuss structure change of soil humus and components of chemical groups in soil humic acids (HA) and fulvic acids (FA) isolated from soils in different fertilization treatment after 26 year's fertilization. The result indicated that using the infrared spectroscopy method for the determination of humus, humus fractions (HA and FA) and their structure is feasible. Fertilization affected the structure and content of soil humus and aromatization degree. After 26 years' fertilization, the infrared spectrum shapes with different treatments are similar, but the characteristic peak intensity is obviously different, which reflects the effects of different fertilization treatments on the structure and amounts of soil humus or functional groups. Compared with no fertilization, little molecule saccharides decreased and aryl-groups increased under application of inorganic fertilizer or combined application of organic and chemical fertilizer. The effect was greater in Treatment NPK and M+NPK than in Treatment M1 N and M2 N. Organic and NPK fertilizer increased the development of soil and increased soil quality to a certain extent. Results showed that organic fertilization increased aromatization degree of soil humus and humus fractions distinctly. The authors could estimate soil humus evolvement of different fertilization with infrared spectroscopy.