Metastatic lymph nodes and prognosis assessed by the number of retrieved lymph nodes in gastric cancer.

BACKGROUND: The prognostic value of quantitative assessments of the number of retrieved lymph nodes (RLNs) in gastric cancer (GC) patients needs further study. AIM: To discuss how to obtain a more accurate count of metastatic lymph nodes (MLNs) based on RLNs in different pT stages and then to evaluate patient prognosis. METHODS: This study retrospectively analyzed patients who underwent GC radical surgery and D2/D2+ LN dissection at the Cancer Hospital of Harbin Medical University from January 2011 to May 2017. Locally weighted smoothing was used to analyze the relationship between RLNs and the number of MLNs. Restricted cubic splines were used to analyze the relationship between RLNs and hazard ratios (HRs), and X-tile was used to determine the optimal cutoff value for RLNs. Patient survival was analyzed with the Kaplan-Meier method and log-rank test. Finally, HRs and 95% confidence intervals were calculated using Cox proportional hazards models to analyze independent risk factors associated with patient outcomes. RESULTS: A total of 4968 patients were included in the training cohort, and 11154 patients were included in the validation cohort. The smooth curve showed that the number of MLNs increased with an increasing number of RLNs, and a nonlinear relationship between RLNs and HRs was observed. X-tile analysis showed that the optimal number of RLNs for pT1-pT4 stage GC patients was 26, 31, 39, and 45, respectively. A greater number of RLNs can reduce the risk of death in patients with pT1, pT2, and pT4 stage cancers but may not reduce the risk of death in patients with pT3 stage cancer. Multivariate analysis showed that RLNs were an independent risk factor associated with the prognosis of patients with pT1-pT4 stage cancer (P = 0.044, P = 0.037, P = 0.003, P < 0.001). CONCLUSION: A greater number of RLNs may not benefit the survival of patients with pT3 stage disease but can benefit the survival of patients with pT1, pT2, and pT4 stage disease. For the pT1, pT2, and pT4 stages, it is recommended to retrieve 26, 31 and 45 LNs, respectively.

Seasonal variations of imidazoles in urban areas of Beijing and Guangzhou, China by single particle mass spectrometry.

Imidazoles (IMs) are potential contributors to brown carbon; they may notably contribute to climate radiative forcing. However, only a few studies have assessed the mixing state, seasonal and spatial distributions of IMs, and influencing factors for IM formation in urban aerosols. In this study, two single-particle aerosol mass spectrometers were employed to investigate the IM-containing particles in the urban areas of Beijing and Guangzhou, China. IM-containing particles were identified in the size range (dva) of 0.2-2.0 µm, accounting for 0.7-21.7 % of all the detected particles. The number fractions of IM-containing particles in both cities were the lowest in winter and the highest in spring, probably owing to the difference in the abundance of precursors and the particle acidity. Majority of (60-80 % by number) the IM-containing particles were mixed with organic carbon (OC), with the lowest fractions found in summer. Although the number fractions of IM-containing particles in Beijing were generally higher (~1.5-3 times) than those in Guangzhou, the mixing states of the IM-containing particles at these two sites were only slightly different. Potassium-rich (K-rich) and potassium-sodium (KNa) particles were rarely found in Guangzhou; they accounted for ~15 % of the IM-containing particles in Beijing. Additionally, our results indicate that particles with higher acidity are favorable for IM formation. These findings help improving our knowledge of the mixing state, seasonal variation, and spatial distribution of IMs in urban aerosols, and the insights in influencing factors into IM formation provide valuable information for future studies of the atmospheric chemical processes associated with IMs.

Prognostic significance of serum inflammation indices for different tumor infiltrative pattern types of gastric cancer.

BACKGROUND: Inflammatory indices are considered to be potential prognostic biomarkers for patients with gastric cancer (GC). However, there is no evidence defining the prognostic significance of inflammatory indices for GC with different tumor infiltrative pattern (INF) types. AIM: To evaluate the significance of inflammatory indices and INF types in predicting the prognosis of patients with GC. METHODS: A total of 962 patients who underwent radical gastrectomy were retrospectively selected for this study. Patients were categorized into the expansive growth type (INFa), the intermediate type (INFb), and the infiltrative growth type (INFc) groups. The cutoff values of inflammatory indices were analyzed by receiver operating characteristic curves. The Kaplan-Meier method and log-rank test were used to analyze overall survival (OS). The chi-square test was used to analyze the association between inflammatory indices and clinical characteristics. The independent risk factors for prognosis in each group were analyzed by univariate and multivariate analyses based on logistic regression. Nomogram models were constructed by R studio. RESULTS: The INFc group had the worst OS (P < 0.001). The systemic immune-inflammation index (P = 0.039) and metastatic lymph node ratio (mLNR) (P = 0.003) were independent risk factors for prognosis in the INFa group. The platelet-lymphocyte ratio (PLR) (P = 0.018), age (P = 0.026), body mass index (P = 0.003), and postsurgical tumor node metastasis (pTNM) stage (P < 0.001) were independent risk factors for prognosis in the INFb group. The PLR (P = 0.021), pTNM stage (P = 0.028), age (P = 0.021), and mLNR (P = 0.002) were independent risk factors for prognosis in the INFc group. The area under the curve of the nomogram model for predicting 5-year survival in the INFa group, INFb group, and INFc group was 0.787, 0.823, and 0.781, respectively. CONCLUSION: The outcome of different INF types GC patients could be assessed by nomograms based on different inflammatory indices and clinicopathologic features.

Heavy haze pollution during the COVID-19 lockdown in the Beijing-Tianjin-Hebei region, China.

To investigate the characteristics of particulate matter with an aerodynamic diameter less than 2.5 µm (PM2.5) and its chemical compositions in the Beijing-Tianjin-Hebei (BTH) region of China during the novel coronavirus disease (COVID-19) lockdown, the ground-based data of PM2.5, trace gases, water-soluble inorganic ions, and organic and elemental carbon were analyzed in three typical cities (Beijing, Tianjin, and Baoding) in the BTH region of China from 5-15 February 2020. The PM2.5 source apportionment was established by combining the weather research and forecasting model and comprehensive air quality model with extensions (WRF-CAMx). The results showed that the maximum daily PM2.5 concentration reached the heavy pollution level (>150 µg/m3) in the above three cities. The sum concentration of SO42-, NO3- and NH4+ played a dominant position in PM2.5 chemical compositions of Beijing, Tianjin, and Baoding; secondary transformation of gaseous pollutants contributed significantly to PM2.5 generation, and the secondary transformation was enhanced as the increased PM2.5 concentrations. The results of WRF-CAMx showed obviously inter-transport of PM2.5 in the BTH region; the contribution of transportation source decreased significantly than previous reports in Beijing, Tianjin, and Baoding during the COVID-19 lockdown; but the contribution of industrial and residential emission sources increased significantly with the increase of PM2.5 concentration, and industry emission sources contributed the most to PM2.5 concentrations. Therefore, control policies should be devoted to reducing industrial emissions and regional joint control strategies to mitigate haze pollution.

Nomograms predicting prognosis of patients with pathological stages T1N2-3 and T3N0 gastric cancer.

BACKGROUND: Patients with pathological stages T1N2-3 (pT1N2-3) and pT3N0 gastric cancer (GC) have not been routinely included in the target population for postoperative chemotherapy according to the Japanese Gastric Cancer Treatment Guideline, and their prognosis is significantly different. AIM: To identify the high-risk patients after radical surgery by analyzing biomarkers and clinicopathological features and construct prognostic models for them. METHODS: A total of 459 patients with pT1N2-3/pT3N0 GC were retrospectively selected for the study. The Chi-square test was used to analyze the differences in the clinicopathological features between the pT1N2-3 and pT3N0 groups. The Kaplan-Meier analysis and log-rank test were used to analyze overall survival (OS). The independent risk factors for patient prognosis were analyzed by univariate and multivariate analyses based on the Cox proportional hazards regression model. The cutoff values of continuous variables were identified by receiver operating characteristic curve. The nomogram models were constructed with R studio. RESULTS: There was no statistically significant difference in OS between the pT1N2-3 and pT3N0 groups (P = 0.374). Prealbumin (P = 0.040), carcino-embryonic antigen (CEA) (P = 0.021), and metastatic lymph node ratio (mLNR) (P = 0.035) were independent risk factors for prognosis in the pT1N2-3 group. Age (P = 0.039), body mass index (BMI) (P = 0.002), and gastrectomy (P < 0.001) were independent risk factors for prognosis in the pT3N0 group. The area under the curve values of the nomogram models for predicting the 5-year prognosis of the pT1N2-3 group and pT3N0 group were 0.765 and 0.699, respectively. CONCLUSION: Nomogram model combining prealbumin, CEA, and mLNR levels can be used to predict the prognosis of pT1N2-3 GC. Nomogram model combining age, BMI, and gastrectomy can be used to predict the prognosis of pT3N0 GC.

Significant reduction in atmospheric organic and elemental carbon in PM2.5 in 2+26 cities in northern China.

To better understand the change characteristics and reduction in organic carbon (OC) and elemental carbon (EC) in particulate matter (PM) with a diameter of ≤2.5 µm (PM2.5) driven by the most stringent clean air policies and pandemic-related lockdown measures in China, a comprehensive field campaign was performed to measure the carbonaceous components in PM2.5 on an hourly basis via harmonized analytical methods in the Beijing-Tianjin-Hebei and its surrounding region (including 2 + 26 cities) from January 1 to December 31, 2020. The results indicated that the annual average concentrations of OC and EC reached as low as 6.6 ± 5.7 and 1.8 ± 1.9 µg/m3, respectively, lower than those obtained in previous studies, which could be attributed to the effectiveness of the Clean Air Action Plan and the impact of the COVID-19-related lockdown measures implemented in China. Marked seasonal and diurnal variations in OC and EC were observed in the 2 + 26 cities. Significant correlations (p < 0.001) between OC and EC were found. The annual average secondary OC levels level ranged from 1.8-5.4 µg/m3, accounting for 37.7-73.0% of the OC concentration in the 2 + 26 cities estimated with the minimum R squared method. Based on Interagency Monitoring of Protected Visual Environments (IMPROVE) algorithms, the light extinction contribution of carbonaceous PM to the total amount reached 21.1% and 26.0% on average, suggesting that carbonaceous PM played a less important role in visibility impairment than did the other chemical components in PM2.5. This study is expected to provide an important real-time dataset and in-depth analysis of the significant reduction in OC and EC in PM2.5 driven by both the Clean Air Action Plan and COVID-19-related lockdown policies over the past few years, which could represent an insightful comparative case study for other developing countries/regions facing similar carbonaceous PM pollution.

[Analysis of Pollution Characteristics, Meteorological Impact, and Forecast Retrospective During the Spring Festival and the Lantern Festival in "2+26" Cities].

The PM2.5concentration characteristics of "2+26" cities in Beijing-Tianjin-Hebei and the surrounding region during the Spring Festival and the Lantern Festival in 2021 were analyzed. The average daily concentration and hourly concentration of PM2.5 in the three days before and after the Spring Festival and the Lantern Festival from 2016 to 2021 and the characteristics of the PM2.5 chemical components during the Spring Festival and the Lantern Festival from 2019 to 2021 were comparatively analyzed. In addition, the impact of meteorological factors on PM2.5 concentration from 2016 to 2021 and the key factors affecting the forecast result of Beijing during the Spring Festival in 2021 were discussed. The results showed that the combination of fireworks and firecrackers and adverse weather conditions resulted in a moderate to heavy pollution process during the Spring Festival in 2021 and a light to moderate pollution process during the Lantern Festival in "2+26" cities. The average ρ(PM2.5) was 111 µg·m-3. The hourly peak ρ(PM2.5) was 156 µg·m-3, which was the lowest in 2016 to 2021. The three days before and after the Lantern Festival in 2021, the average ρ(PM2.5) of "2+26" cities was 85 µg·m-3, and the hourly peak ρ(PM2.5) was 125 µg·m-3. During this period, the hour number of heavy and severe pollution was the lowest in 2016 to 2021. Component observation results showed that the impact of fireworks and firecrackers during the Spring Festival and the Lantern Festival in 2021 was gradually reduced, and the effect of bans and restrictions for fireworks and firecrackers was significant. The regional pollution was dominated by conventional pollution accumulation and nitrate. The concentration of organic matter in some cities during the Spring Festival was relatively high, which may be related to local industrial emissions and the impact of blasting fireworks and firecrackers. The comparative analysis of meteorological factors and PM2.5 concentration showed that the factors such as wind speed and direction, ground pressure, and relative humidity all affected PM2.5 concentration and the duration of the regional pollution process. The influence of oscillation of the boundary layer transport sink on diffusion conditions in the North China Plain, the location and intensity of the small high pressure in North China and the intensity of its high-altitude moving airflow, and the uncertainty of fireworks displays, as well as the low accuracy of weather forecasts caused by frequent weather changes during the alternate period of winter and spring, could affect the accuracy of air quality forecast results in the northern Beijing-Tianjin-Hebei region. In summary, although the impact of fireworks and firecrackers has been reduced in recent years, in order to improve the air quality, it is recommended to further strengthen the control of fireworks and firecrackers, especially outside the Beijing Fifth Ring Road and Beijing's surrounding cities.

Historically understanding the spatial distributions of particle surface area concentrations over China estimated using a non-parametric machine learning method.

A non-parametric ensemble model was proposed to estimate the long-term (2015-2019) particle surface area concentrations (SA) over China for the first time on basis of a vilification dataset of measured particle number size distribution. This ensemble model showed excellent cross-validation R2 value (CV R2 = 0.83) as well as a relatively low root-mean-square error (RMSE = 195.0 µm2/cm3). No matter in which year, considerable spatial heterogeneity of SA was found over China with higher SA in Beijing-Tianjin-Hebei (BTH), Yangtze River Delta (YRD), and Middle Lower Reaches of Yangtze River (MLYR). From 2015 to 2019, SA significantly decreased in representative city clusters. The reduction rates were 140.1 µm2·cm-3·a-1 in BTH, 110.7 µm2·cm-3·a-1 in Pearl River Delta (PRD), 105.2 µm2·cm-3·a-1 in YRD, and 92.4 µm2·cm-3·a-1 in Sichuan Basin (SCB), respectively. Even though such quick reduction, high SA (ranged from ~800 µm2/cm3 to ~1750 µm2/cm3) during the heavy pollution period (PM2.5 > 75 µg/m3) still existed in the above-mentioned city clusters and may provide rich reaction vessels for multiphase chemistry. A dichotomy of enhanced annual 4th maximum daily 8-h average O3 concentrations (4MDA8 O3) and decreased SA during summertime was found in Shanghai, a representative city of YRD. In Chengdu (SCB), increased 4MDA8 O3 concentration was associated with a synchronous increase of SA from 2017 to 2019. Differently, 4MDA8 O3 concentrations enhanced in Beijing (BTH) and Guangzhou (PRD), while not significant for SA before 2018. This work will greatly deepen our understanding of the historical variation and spatial distributions of SA over China.

Composition and sources of particulate matter in the Beijing-Tianjin-Hebei region and its surrounding areas during the heating season.

This paper aimed to analyze the composition and pollution sources of particulate matter (PM) in the Beijing-Tianjin-Hebei region and its surrounding areas (henceforth the BTH region) during the heating season to support the mitigation and control of regional air pollution. Manual monitoring data from the China National Environmental Monitoring Network for Atmospheric PM in the BTH region were collected and analyzed during the 2016 and 2018 heating seasons. The positive definite matrix factor analysis (PMF) model was used to analyze the PM sources in BTH cities during the heating season. The main PM components were organic matter (OM), nitrate (NO3-), sulfate (SO42-) and ammonium salt (NH4+). Direct emission sources have decreased since 2016, indicating the effectiveness of governmental controls on these sources; however, secondary pollution showed an increasing trend, suggesting control measures should be strengthened. Daily regional average concentrations of OM, SO42-, NH4+, elemental carbon (EC), chloride (Cl-) and trace elements all showed similar trends. When air quality worsened, the concentrations of the main PM components increased, but trends of change varied among components. In 2018, concentrations of OM and chloride were highest in the Taihang Mountains, and NO3 concentrations were highest in Anyang, Hebi, Jiaozuo and Xinxiang. The SO42- concentration was highest in the southern section of the Taihang Mountains. The NH4+ and EC concentrations were generally highest in the central and southern regions. The concentration of crustal substances was highest in some cities in the north and central parts of the BTH region. In the 2018 heating season, the pollution level of five transmission channels showed an increasing trend in the Northwest, Southeast, Yanshan, South and Taihang Mountain channels. These findings provide a scientific basis for the continued management of atmospheric PM pollution.

Comparative observation of aerosol vertical profiles in urban and suburban areas: Impacts of local and regional transport.

Ground-based Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) instruments were used to carry out observation of aerosol in the urban and suburban areas of Shanghai from October 17 to November 21, 2019. Fudan University (FDU) site is a typical urban environment, surrounded by residential areas, commercial areas and arterial roads, while Dianshan Lake (DSL) site is a suburban environment with high vegetation coverage and no pollutant emission sources. The aerosol retrieved by MAX-DOAS was in good correlation with the observation of sun photometer and the PM2.5 concentration of the corresponding site, which demonstrates that the aerosol retrieved by MAX-DOAS is reliable and feasible. Comparing the mean aerosol extinction coefficient (AEC) profiles during the observation period between urban and suburban areas, it was found that the occurrence of high aerosol concentration at FDU was nearly 3 h later than that of DSL at suburban site. And the aerosol at DSL was concentrated at an altitude of 0.3- 0.5 km, with a mean peak value of 0.486 km-1, which was slightly higher than the peak AEC of 0.453 km-1 at FDU of 0.2- 0.4 km. The difference in aerosol characteristics between the two sites may be due to the fact that the influences of aerosol transport and boundary layer dynamics are different between the two sites. The backward trajectories analysis also presents that there were mutual transports of aerosol between urban and suburban areas, which affect the optical properties of the aerosol in these two sites. In a case of aerosol pollution, we visualized the transport pathway of aerosol from the western part of the North China Plain to Shanghai using AEC profiles and backward trajectories, providing the evidence that the local aerosol pollution in Shanghai was affected by long-distance transport.

[Determination of 104 volatile organic compounds in air by double column gas chromatography-mass spectrometry/flame ionization detector coupled with electronically controlled cryo-focusing unit].

A method for the determination of 104 volatile organic compounds (VOCs) in ambient air based on double column multi dean switching gas chromatography-mass spectrometry/flame ionization detector (GC-MS/FID) coupled with sorbent assisted electronically controlled cryo-focusing unit was developed and evaluated. The sorbent assisted electronically controlled cryo-focusing unit was used for trapping, dehydration and focusing of VOCs sampled in summa canisters. The VOCs were split into two parts by the multi dean switching unit in GC-MS/FID. The C2-C3 components were determined in a PLOT capillary column with an FID detector, while the C4-C12 components were determined in an Intercap-624 capillary column with a MS detector. The C2-C3 components were qualitatively confirmed from the retention time and quantified by the calibration curves, while the C4-C12 components were qualitatively confirmed from the retention time and the relative abundance ratio of characteristic ions, and quantified by the internal standard calibration curves. The major factors influencing the cryo-focusing performance including the type of sorbent tube, the pressure employed in assisted pressure control unit (APC), and the split point in multi dean switching unit were investigated. The chromatographic and MS parameters were optimized. Under optimum conditions, a linear relationship was observed with the content of VOCs ranging from 0.0446 to 0.892 µmol/m3, and correlation coefficients (r) no less than 0.9984. The average spiked recoveries of the six VOCs at two levels of 0.0446 µmol/m3 and 0.223 µmol/m3 were 86.4%-116.1%, with relative standard deviations in the range of 0.9%-11.3% The method detection limits (MDLs) and the limits of quantification (LOQs) were 0.145-1.90 µg/m3 and 0.435-5.70 µg/m3, respectively. The method is accurate, sensitive and simple, and is suitable for the determination of the 104 VOCs in ambient air.

Clinical analysis of low molecular weight heparin calcium combined with psychological intervention in treatment of recurrent spontaneous abortion / 中国生化药物杂志

Objective To explore the clinical effect of low molecular weight heparin calcium combined with psychological intervention in the treatment of recurrent spontaneous abortion. Methods 60 patients were treated with recurrent miscarriage after treatment in our hospital from October 2016 to June 2017, and these patients were randomly divided into two groups: control group and observation group.Each group of 30 cases. First of all, the two groups of patients were treated with low molecular weight heparin calcium, and then the control group of patients to choose the most commonly used care methods for nursing operations,the observation group of patients choose to use more targeted psychological intervention care for nursing work.The clinical effects of the two groups were observed and compared. Results There was no significant difference between the two groups. The adverse reaction rate was 10.00% in the observation group and the control group The adverse reaction rate was 26.67%. The adverse reaction rate of the observation group was significantly lower than that of the control group.The difference between the two groups was statistically significant (P<0.05). Conclusion Recurrence of recurrent miscarriage after treatment of patients with more targeted psychological intervention in nursing care,compared to conventional care methods better,while effectively reducing the low molecular weight heparin calcium treatment of recurrent miscarriage of adverse reactions.The incidence of psychological intervention in the care of the clinical way is a worthy of use and to promote the treatment.

Clinical analysis of low molecular weight heparin calcium combined with psychological intervention in treatment of recurrent spontaneous abortion / 中国生化药物杂志

Objective To explore the clinical effect of low molecular weight heparin calcium combined with psychological intervention in the treatment of recurrent spontaneous abortion. Methods 60 patients were treated with recurrent miscarriage after treatment in our hospital from October 2016 to June 2017, and these patients were randomly divided into two groups: control group and observation group.Each group of 30 cases. First of all, the two groups of patients were treated with low molecular weight heparin calcium, and then the control group of patients to choose the most commonly used care methods for nursing operations,the observation group of patients choose to use more targeted psychological intervention care for nursing work.The clinical effects of the two groups were observed and compared. Results There was no significant difference between the two groups. The adverse reaction rate was 10.00% in the observation group and the control group The adverse reaction rate was 26.67%. The adverse reaction rate of the observation group was significantly lower than that of the control group.The difference between the two groups was statistically significant (P<0.05). Conclusion Recurrence of recurrent miscarriage after treatment of patients with more targeted psychological intervention in nursing care,compared to conventional care methods better,while effectively reducing the low molecular weight heparin calcium treatment of recurrent miscarriage of adverse reactions.The incidence of psychological intervention in the care of the clinical way is a worthy of use and to promote the treatment.

Determination of notoginsenoside R1, ginsenosides Rg1 and Rb1 in Xixian Tongshuan pills by HPLC / 国际药学研究杂志

Objective To establish a HPLC method for determining notoginsenoside R1, and ginsenosides Rg1 and Rb1 in Xixian Tongshuan pills. Methods C18 column was adopted with acetonitrile as mobile phase A, water as mobile phase B, gradient elution. The flow rate was 1.0 ml/min, column temperature was 35°C and detection wavelength was 203 nm. Results The linear range of notoginsenoside R1, and ginsenosides Rg1 and Rb1 was 0.412-1.855 µg(r=0.9994), 1.903-8.563 µg(r=0.9994), and 1.822-8.201 µg(r=1.0000), respectively. The total average recovery rate of notoginsenoside R1, and ginsenosides Rg1 and Rb1 was 98.48%, 97.33% and 97.29% with RSD of 1.58%, 1.13% and 1.08%, respectively. Conclusion The method is reliable, accurate, and can be used for the quality control of the preparation.

Chemical characteristics of water-soluble ions in particulate matter in three metropolitan areas in the North China Plain.

PM2.5 and PM10 samples were collected simultaneously in each season in Beijing, Tianjin and Shijiazhuang to identify the characteristics of water-soluble ion compositions in the North China Plain. The water-soluble ions displayed significant seasonal variation. The dominant ions were NO3(-), SO4(2-), NH4(+) and Cl(-), accounting for more than 90% and 86% to the mass of total water-soluble ions in PM2.5 and PM10, respectively. The anion/cation ratio indicated that the ion acidity of each city varied both between sites and seasonally. Over 50% of the ion species were enriched in small particles ≤1 µm in diameter. The [NO3(-)]/[SO4(2-)] ratio indicated that vehicles accounted for the majority of the particulate pollution in Beijing. Shijiazhuang, a city highly reliant on coal combustion, had a higher SO4(2-) concentration.

[Determination of hexavalent chromium in atmospheric particles PM2.5 and PM10 by ion chromatography with inductively coupled plasma mass spectrometry].

An analytical method using ion chromatography with inductively coupled plasma mass spectrometry (IC-ICP-MS) for the determination of hexavalent chromium (Cr(VI)) in atmospheric particles PM2.5 and PM10 was established. The Cr(VI) in the atmospheric particles was extracted ultrasonically with sodium bicarbonate solution. An anion exchange column (AG7, 50 mm x 4 mm) with 75 mmol/L ammonium nitrate solution (containing 0.22 g/L Na2EDTA, pH 7.0) as mobile phase was used for the separation. ICP-MS was used as a detector for the determination of hexavalent chromium. The calibration curve was linear in the range of 0.05-5 µg/L and the correlation coefficient was 0.999 9 for Cr(VI). The cellulose filter was fit for sampling. With the alkaline cellulose filter, the recovery of Cr(VI) increased from 75% to 102%. The recovery was complete and stable when the samples were sonicated in 20 mmol/L sodium bicarbonate solution for 30 min. The limit of quantification (LOQ) of Cr(VI) was 0.000 4 ng/m3 when the sampling volume was 20 m3. The average recoveries of Cr(VI) in the spiked PM2.5 and PM10 samples ranged from 91.6% to 102% with the relative standard deviations not more than 7.6%. The method is efficient and reliable. It can meet the requirement for the determination of Cr(VI) in atmospheric particles.

Analysis of spatial and temporal water pollution patterns in Lake Dianchi using multivariate statistical methods.

Various multivariate statistical methods including cluster analysis (CA), discriminant analysis (DA), factor analysis (FA), and principal component analysis (PCA) were used to explain the spatial and temporal patterns of surface water pollution in Lake Dianchi. The dataset, obtained during the period 2003-2007 from the Kunming Environmental Monitoring Center, consisted of 12 variables surveyed monthly at eight sites. The CA grouped the 12 months into two groups, August-September and the remainder, and divided the lake into two regions based on their different physicochemical properties and pollution levels. The DA showed the best results for data reduction and pattern recognition in both temporal and spatial analysis. It calculated four parameters (TEMP, pH, CODMn, and Chl-a) to 85.4% correct assignment in the temporal analysis and three parameters (BOD, NH4+-N, and TN) to almost 71.7% correct assignment in spatial analysis of the two clusters. The FA/PCA applied to datasets of two special clusters of the lake calculated four factors for each region, capturing 72.5% and 62.5% of the total variance, respectively. Strong loadings included DO, BOD, TN, CODCr, CODMn, NH4+-N, TP, and EC. In addition, box-whisker plots and GIS further facilitated and supported the multivariate analysis results.

Regulation of zinc transporters by dietary flaxseed lignan in human breast cancer xenografts.

Zinc is essential for cell growth. Previous studies have shown that zinc concentration in breast cancer tissues is higher than that in normal breast tissues. Zinc cannot passively diffuse across cell membranes and specific zinc transporter proteins are required. Two gene families have been identified involved in zinc homeostasis. ZnT transporters reduce intracellular zinc while ZIP transporters increase intracellular zinc. In this study, three human zinc transporter members: ZnT-1, ZIP2 and LIV-1 were chosen. We aimed to determine the effect of flaxseed lignan on the growth of ER-negative breast cancer cells in a nude mice model and observe the effect of flaxseed lignan on the regulation of the three zinc transporter in mRNA level. Nude mice were xenografted with human breast cancer cell line MDA-MB-231 and 6 weeks later were fed either the basal diet (BD) or BD supplemented with 10% FS and SDG for 5 weeks. The SDG levels were equivalent to the amounts in the 10% FS. RT-PCR was performed. Compared with the BD group, the tumor growth rate was significantly lower (P < 0. 05) in the FS and SDG group. ZnT-1 mRNA level in mammary tumor was increased in SDG group and decreased in FS group, but no significant difference was found. Extremely low amplification of ZIP2 from mRNA was detected, with no difference between the treatment groups. LIV-1 mRNA expression of SDG group increases compared with BD group. In FS group, it significantly increases nearly 9 times than that in BD group (P < 0. 005).

A STUDY ON THE NUTRITIVE VALUE OF INFANT STAPLE FOOD SPRAYS IN RATS / 营养学报

Three infant staple food sprays were studied. Preparation A contained 17.5% cow's milk powder, preparations B and C contained 30% and 26% soybean powder respectively, preparations A and B both contained 22% cane sugar; while C was without cane sugar. Other components in these 3 sprays were mainly rice powder and a little amount of soybean oil and whole egg powder. 3 preparations were fed to 3 groups of male weaning rats for 4 weeks. As indicated by parameters such as body weights gained, FE, CE and PER, preparation C had a significantly higher value than A and B. A and B got a practically similar results. Those effects were also true in a repletion test. The BV and nitrogen balance values were similar among these 3 preparations. There was no prominent effect on serum osmotic pressure in rats fed 22% cane sugar for 4 weeks, but had a lower caloric utilization in group A and B as compared with group C