Clinical outcomes and biomarker exploration of first-line PD-1 inhibitors plus chemotherapy in patients with low PD-L1-expressing of gastric or gastroesophageal junction adenocarcinoma.

BACKGROUND: The beneficial effects of first-line programmed death-1 (PD-1) inhibitors plus chemotherapy in patients with low programmed death-ligand 1 (PD-L1)-expressing advanced gastric or gastroesophageal junction (G/GEJ) adenocarcinoma are controversial. METHODS: We conducted a retrospective analysis of patients with G/GEJ adenocarcinoma who had undergone first-line treatment with PD-1 inhibitors plus chemotherapy between October 2017 and May 2022. The primary outcomes were objective response rate (ORR) and progression-free survival (PFS). SPSS software V27.0 was used for data analysis. RESULTS: Of 345 enrolled patients, 290 had measurable lesions. The overall ORR was 59.3%. PD-L1 status was available in 171 patients, and 67.8% of them were considered as low PD-L1 expression level (combined positive score (CPS) < 5). Patients with PD-L1 CPS < 5 showed a lower response rate (51.1% vs 70.8%, P = 0.024) and a worse PFS (P = 0.009) compared to those with PD-L1 CPS ≥ 5. In the PD-L1 low-expression cohort, patients with non-diffuse type, GEJ cancer, synchronous metastasis, distant lymph node metastasis, liver metastasis, non-peritoneal metastasis, and HER2 positive were significantly associated with higher response rates to PD-1 inhibitors plus chemotherapy (P < 0.05). The presence of peritoneal metastasis (P = 0.028) and diffuse type (P = 0.046) were identified as independent predictors of poor PFS in multivariate analysis of the PD-L1 CPS < 5 subgroup. When evaluated for correlation with overall survival (OS) in the PD-L1 low-expression subgroup, peritoneal metastasis was found to be the only independent prognostic factor of an increased risk of death (hazard ratio: 2.31, 95% CI 1.09-4.90; P = 0.029). CONCLUSIONS: PD-L1 CPS ≥ 5 is significantly associated with improved response and extended PFS in G/GEJ cancer patients treated with a combination of PD-1 inhibitors and chemotherapy. Specific subgroups within the low PD-L1-expressing population, such as those with non-diffuse-type tumors and without peritoneal metastases, may also benefit from immunotherapy combined with chemotherapy.

The relationship between brain metastasis and HER2 expression status in gastric cancer.

BACKGROUND: Brain metastasis (BM) in gastric cancer (GC) is underestimated, and human epidermal growth factor receptor 2 (HER2) overexpression is a durable poor prognostic factor. We explored the relationship between the two and made a survival analysis. METHODS: HER2 expression and BM status were collected from GC patients who were diagnosed between December 2009 and May 2021. We collected GC patients diagnosed between 2010 and 2016 from the SEER database. The primary endpoint was survival from the diagnosis of BM. Multivariable logistic regression was used to determine potential risk factors of BM at diagnosis in SEER database. Survival analysis was performed using the Kaplan-Meier method. RESULT: There were 513 HER2-positive GC patients, including 16 (3.1%) with BM. Among 38 brain metastasis GC patients we collected, 16 (42.1%) patients were HER2 positive. We collected 34,199 GC patients from the SEER database and there were 260 (0.76%) patients with BM at diagnosis. GC patients that are male, white, of younger age, with primary lesions located in the proximal stomach or with distant lymph nodes, liver, bone, or lung metastasis are more likely to develop BM. The median overall survival time from diagnosis of BM was 12.73 months, and the survival time from brain metastasis of HER2-positive patients was numerically shorter, though the difference was not significant (5.30 months vs.16.13 months, P = 0.28.) CONCLUSION: The incidence of BM in patients with HER2-positive gastric cancer is 4.08 times higher than that in general patients. The median overall survival time from BM is shorter for HER2-positive patients.

Dynamic single-cell mapping unveils Epstein‒Barr virus-imprinted T-cell exhaustion and on-treatment response.

Epstein‒Barr virus (EBV)-associated gastric cancer (GC) manifests an intriguing immunotherapy response. However, the cellular basis for EBV-imprinted tumour immunity and on-treatment response remains undefined. This study aimed to finely characterize the dynamic tumour immune contexture of human EBV (+) GC treated with immunochemotherapy by longitudinal scRNA-seq and paired scTCR/BCR-seq. EBV (+) GC exhibits an inflamed-immune phenotype with increased T-cell and B-cell infiltration. Immunochemotherapy triggers clonal revival and reinvigoration of effector T cells which step to determine treatment response. Typically, an antigen-specific ISG-15+CD8+ T-cell population is highly enriched in EBV (+) GC patients, which represents a transitory exhaustion state. Importantly, baseline intratumoural ISG-15+CD8+ T cells predict immunotherapy responsiveness among GC patients. Re-emerged clonotypes of pre-existing ISG-15+CD8+ T cells could be found after treatment, which gives rise to a CXCL13-expressing effector population in responsive EBV (+) tumours. However, LAG-3 retention may render the ISG-15+CD8+ T cells into a terminal exhaustion state in non-responsive EBV (+) tumours. In accordance, anti-LAG-3 therapy could effectively reduce tumour burden in refractory EBV (+) GC patients. Our results delineate a distinct implication of EBV-imprinted on-treatment T-cell immunity in GC, which could be leveraged to optimize the rational design of precision immunotherapy.

Precise microdissection of gastric mixed adeno-neuroendocrine carcinoma dissects its genomic landscape and evolutionary clonal origins.

Gastric mixed adenoneuroendocrine carcinoma (MANEC) is a clinically aggressive and heterogeneous tumor composed of adenocarcinoma (ACA) and neuroendocrine carcinoma (NEC). The genomic properties and evolutionary clonal origins of MANEC remain unclear. We conduct whole-exome and multiregional sequencing on 101 samples from 33 patients to elucidate their evolutionary paths. We identify four significantly mutated genes, TP53, RB1, APC, and CTNNB1. MANEC resembles chromosomal instability stomach adenocarcinoma in that whole-genome doubling in MANEC is predominant and occurs earlier than most copy-number losses. All tumors are of monoclonal origin, and NEC components show more aggressive genomic properties than their ACA counterparts. The phylogenetic trees show two tumor divergence patterns, including sequential and parallel divergence. Furthermore, ACA-to-NEC rather than NEC-to-ACA transition is confirmed by immunohistochemistry on 6 biomarkers in ACA- and NEC-dominant regions. These results provide insights into the clonal origin and tumor differentiation of MANEC.

A novel nomogram integrated with PDL1 and CEA to predict the prognosis of patients with gastric cancer.

INTRODUCTION: This study aimed to develop a prognostic nomogram for patients with gastric cancer (GC) based on the levels of programmed death 1 ligand 1 (PDL1) and carcinoembryonic antigen (CEA). METHODS: The nomogram was developed using data from a primary cohort of 247 patients who had been clinicopathologically diagnosed with GC, as well as a validation cohort of 63 patients. Furthermore, the nomogram divided the patients into three different risk groups for overall survival (OS)-the low-risk, middle-risk, and high-risk groups. Univariate and multivariate Cox hazard analyses were used to determine all of the factors included in the model. Decision curve analysis and receiver operating characteristic (ROC) curves were used to assess the accuracy of the nomogram. RESULTS: The Kaplan-Meier survival analysis revealed that metastasis stage, clinical stage, and CEA and PDL1 levels were predictors for progress-free survival (PFS) and OS of patients with GC. Metastasis stage, clinical stage, and CEA and PDL1 levels were found to be independent risk factors for the PFS and OS of patients with GC in a multivariate analysis, and the nomogram was based on these factors. The concordance index of the nomogram was 0.763 [95% confidence interval (CI) 0.740-0.787]. The area under the concentration-time curve of the nomogram model was 0.81 (95% CI 0.780-0.900). According to the decision curve analysis and ROC curves, the nomogram model had a higher overall net efficiency in forecasting OS than clinical stage, CEA and PDL1 levels. CONCLUSION: In conclusion, we proposed a novel nomogram that integrated PDL1 and CEA, and the proposed nomogram provided more accurate and useful prognostic predictions for patients with GC.

Facial muscle movements in patients with Parkinson's disease undergoing phonation tests.

Purpose: Parkinson's disease (PD) is a serious neurodegenerative disease affecting the elderly. In general, the locomotion deficit, which seriously affects the daily life of patients with PD, usually occurs at a later stage. The mask face symptom meanwhile progressively worsens. However, facial muscle disorders and changes involved in the freezing mask are unclear. Method: In this study, we recruited 35 patients with PD and 26 age- and sex-balanced controls to undergo phonation tests, while the built-in camera on the laptop recorded their facial expressions during the whole pronunciation process. Furthermore, FaceReader (version 7.0; Noldus Information Technology, Wageningen, Netherlands) was used to analyze changes in PD facial landmark movement and region movement. Results: The two-tailed Student's t-test showed that the changes in facial landmark movement among 49 landmarks were significantly lower in patients with PD than in the control group (P < 0.05). The data on facial region movement revealed that the eyes and upper lip of patients with PD differed significantly from those in the control group. Conclusion: Patients with PD had defects in facial landmark movement and regional movement when producing a single syllable, double syllable, and multiple syllables, which may be related to reduced facial expressions in patients with PD.

Comparison of response evaluation criteria in solid tumors and tumor regression grade in evaluating the effect of preoperative systemic therapy of gastric cancer.

BACKGROUND: Both Response Evaluation Criteria in Solid Tumors (RECIST) and tumor regression grade (TRG) play key roles in evaluating tumor response. We analyzed the consistency of TRG and RECIST 1.1 for gastric cancer (GC) patients and compared their prognostic values. METHODS: Patients with GC who received preoperative chemotherapy or chemoimmunotherapy and had records of TRG from December 2013 to October 2021 were enrolled retrospectively. TRG 0-1 and 2-3 are considered as corresponding to complete response (CR)/partial response (PR) and stable disease (SD)/progress disease (PD) in RECIST 1.1, respectively. The primary endpoints were disease-free survival (DFS) and overall survival (OS). The consistency of RECIST and TRG was examined by kappa statistics. Survival analysis was performed using the Kaplan Meier method. RESULT: One hundred fifty seven GC patients were enrolled, including 125 with preoperative chemotherapy and 32 with chemoimmunotherapy. Among them, 56 patients had measurable lesions. Only 19.6% (11/56) of the patients had consistent results between RECIST 1.1 and TRG. TRG was correlated with both OS and DFS (P = 0.02 and 0.03, respectively) while response according to RECIST1.1 was not (P = 0.86 and 0.23, respectively). The median DFS had not reached in the TRG 0-1 group and was 16.13 months in TRG 2-3 group. TRG 2-3 was associated with young age and peritoneal or liver metastasis. Besides, preoperative chemoimmunotherapy had a significantly higher pCR rate than chemotherapy alone (34.4% vs 8.0%, P < 0.001). CONCLUSION: TRG was in poor agreement with RECIST 1.1. TRG was better than RECIST 1.1 in predicting DFS and OS for GC patients who received preoperative therapy.

Novel prognostic model predicts overall survival in colon cancer based on RNA splicing regulation gene expression.

Colon cancer is the third most common cancer and the second leading cause of cancer-related death worldwide. Dysregulated RNA splicing factors have been reported to be associated with tumorigenesis and development in colon cancer. In this study, we interrogated clinical and RNA expression data of colon cancer patients from The Cancer Genome Atlas (TCGA) dataset and the Gene Expression Omnibus (GEO) database. Genes regulating RNA splicing correlated with survival in colon cancer were identified and a risk score model was constructed using Cox regression analyses. In the risk model, RNA splicing factor peroxisome proliferator-activated receptor-γ coactivator-1α (PPARGC1) is correlated with a good survival outcome, whereas Cdc2-like kinase 1(CLK1), CLK2, and A-kinase anchor protein 8-like (AKAP8L) with a bad survival outcome. The risk model has a good performance for clinical prognostic prediction both in the TCGA cohort and the other two validation cohorts. In the tumor microenvironment (TME) analysis, the immune score was higher in the low-risk group, and TME-related pathway gene expression was also higher in low-risk group. We further verified the mRNA and protein expression levels of these four genes in the adjacent nontumor, tumor, and liver metastasis tissues of colon cancer patients, which were consistent with bioinformatics analysis. In addition, knockdown of AKAP8L can suppress the proliferation and migration of colon cancer cells. Animal studies have also shown that AKAP8L knockdown can inhibit tumor growth in colon cancer in vivo. We established a prognostic risk model for colon cancer based on genes related to RNA splicing regulation and uncovered the role of AKAP8L in promoting colon cancer progression.

High AKAP8L expression predicts poor prognosis in esophageal squamous cell carcinoma.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is a severe disease with high mortality, and is associated with poor prognosis and frequent lymphatic metastasis. Therefore, prognostic indicators for ESCC are urgently needed. A-kinase anchor-protein 8-like (AKAP8L) is a member of the A kinase anchor-protein (AKAPs) family and is overexpressed in many cancers. However, the role of AKAP8L in ESCC remains unclear. The aim of this study is to investigate the expression patterns and prognostic value of AKAP8L in ESCC. METHODS: The mRNA expression of AKAP8L was analyzed from the dataset of The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO). Immunohistochemistry was applied to detect the AKAP8L expression in tissue microarray. Pearson's chi-square test was carried out for the correlation analysis of clinicopathological features and AKAP8L expression. The prognostic significance of clinicopathological features and AKAP8L expression was determined by univariate and multivariate Cox hazard models. Kaplan-Meier survival curve was used for survival analysis. RESULTS: We found that the mRNA level of AKAP8L was higher in tumor tissues than in adjacent tissues in TCGA and GEO dataset. High AKAP8L expression was associated with poor overall survival (OS) in ESCC patients (p = 0.0039). Besides, AKAP8L expression was highly expressed in patients with lymph node metastasis detected by ESCC tissue microarray (p = 0.0014). The comparison of the different clinicopathological features of ESCC between high and low AKAP8L expression groups revealed that high AKAP8L expression was related to lymph node stage (p = 0.041). Kaplan-Meier survival analysis revealed that high AKAP8L expression indicates an unfavorable progression-free survival (PFS) and OS in ESCC patients (p < 0.0001). Univariate and multivariate analyses confirmed that AKAP8L was an independent prognostic factor for PFS and OS in ESCC (p = 0.003 and p < 0.0001). CONCLUSIONS: In conclusion, this study demonstrated that high expression of AKAP8L is associated with poor prognosis of ESCC and can be considered an independent risk factor for ESCC.

The Impact of Mismatch Repair Status on Prognosis of Patients With Gastric Cancer: A Multicenter Analysis.

BACKGROUND: The clinical role of deficient DNA mismatch repair (dMMR)/microsatellite instability-high (MSI-H) in gastric cancer (GC) is still controversial. We aimed to analyze the relationship between dMMR/MSI-H and clinicopathological features along with survival. METHODS: Patients who were diagnosed with GC at the three big cancer centers in China from 2015 to 2020 were evaluated retrospectively. MMR/MSI status was assessed using immunohistochemistry/PCR. Clinical and pathological data were collected from the medical record system. RESULTS: A total of 196 patients with dMMR/MSI-H status were enrolled for analysis. The prevalence of MSI-H/dMMR in GC was 6.6%. Another 694 proficient MMR (pMMR) GC patients were enrolled for comparison. Compared with pMMR patients, dMMR/MSI-H patients were associated with older age, female predominance, distal location in the stomach, earlier TNM stage, intestinal subtype, better differentiation, and more negative HER2 status. The median overall survival (OS) of the dMMR/MSI-H group was better than that of the pMMR/microsatellite stability (MSS) group (not reached vs. 53.9 months, p = 0.014). Adjuvant chemotherapy had no impact in both disease-free survival (DFS) and OS of dMMR/MSI-H patients (p = 0.135 and 0.818, respectively). dMMR/MSI-H patients had poorer response and progression-free survival (PFS) of first-line chemotherapy, though they were statistically significant (p = 0.361 and 0.124, respectively). CONCLUSIONS: dMMR/MSI-H GC patients have specific clinicopathological characteristics and better prognosis than pMMR patients.

Relationship of HER2 Alteration and Microsatellite Instability Status in Colorectal Adenocarcinoma.

BACKGROUND: The impact of HER2 somatic mutations in colorectal carcinoma (CRC) has not been well studied and its relationship with microsatellite instability-high (MSI-H) is yet to be fully elucidated. MATERIALS AND METHODS: From February 2017 to February 2020, the data of patients with CRC who underwent next-generation sequencing and had detailed record of clinicopathological information were investigated. HER2 alteration and its relationship with MSI-H were analyzed. RESULTS: Among 731 patients who underwent sequencing, 55 patients (7.5%) had HER2 alteration, including 29 (4.0%) with HER2 somatic mutations, 24 (3.3%) with HER2 gene amplification, and 2 patients (0.2%) with both HER2 mutations and amplification. R678Q was the most common mutated kinase domain, and no HER2 kinase domain in-frame insertions/deletions were found in HER2 mutated cases. MSI-H was found in 5.2% of our cohort and 36.8% of MSI-H patients had HER2 mutation. For HER2 mutated cases, 48.3% were MSI-H, whereas none of the HER2 amplification cases were MSI-H. MSI-H patients with HER2 mutation had significantly worse median progression-free survival for programmed death-1 (PD-1) antibody than those without HER2 alteration (p = .036). CONCLUSION: High MSI-H rate was found in HER2 mutated cases, but no MSI-H was found in HER2 amplification cases. MSI-H patients with HER2 mutated had worse progression-free survival for PD-1 antibody than those without. IMPLICATIONS FOR PRACTICE: This study highlights the high microsatellite instability-high (MSI-H) rate in HER2 mutated cases but no MSI-H in HER2 amplification cases. Moreover MSI-H patients with HER2 mutated had worse progression-free survival for programmed death-1 antibody than those without. Further research to explore the internal relationship between HER2 alteration and MSI-H is needed.

A multi-kinase inhibitor APG-2449 enhances the antitumor effect of ibrutinib in esophageal squamous cell carcinoma via EGFR/FAK pathway inhibition.

Esophageal squamous cell carcinoma (ESCC) is one of the most common types of cancer in China, with poor prognosis and lack of effective targeted therapy. It has been reported that ibrutinib possesses anticancer activity in ESCC with MYC and/or ERBB2 amplification. Here we explored the synergistic antitumor effect of a novel multi-kinase inhibitor APG-2449 with ibrutinib in ESCC and clarified the mechanism of the combination effect through in vitro and in vivo experiment. We found that APG-2449 exerted antitumor effect in ESCC. APG-2449 combined with ibrutinib showed synergistic inhibition of cell viability in ESCC cell lines. APG-2449 combined with ibrutinib dramatically inhibited the proliferation and migration of ESCC cells. Furthermore, we observed that ibrutinib combined with APG-2449 could induce more cancer cells arrested in the G1/S phase and apoptosis. In terms of mechanism, ibrutinib alone could decrease the phosphorylation level of EGFR and its downstream pathway of MEK/ERK. The combination therapy of APG-2449 and ibrutinib could significantly down-regulate the phosphorylation level of MEK/ERK and AKT. In ESCC xenotransplantation models, single therapy with either ibrutinib or APG-2449 was equivalent in delaying tumor growth, while the combination therapy suppressed tumor growth more significantly. Our data strongly suggest that the combination therapy of APG-2449 and ibrutinib can provide an effective therapeutic strategy for ESCC patients, which deserved further clinical investigation.

Clinicopathologic Features and Prognosis of BRAF Mutated Colorectal Cancer Patients.

Background: BRAF V600E mutation is associated with poor prognosis of colorectal cancer (CRC) patients, but the comparison of clinic-pathologic features between V600E and non-V600E mutation was not well-known in CRC patients. The aim of this study is to evaluate the clinical and pathological features, prognostic value of BRAF mutations in CRC. Methods: We conducted a retrospective study to characterize the clinical and pathological features and survival of patients with BRAF mutated CRC. Patients were classified according to BRAF status as BRAF V600E mutation and non-V600E mutations. Difference of characteristics and survival between the two groups was analyzed. Results: There was no significant difference in gender, family history, location of primary tumor, metastatic sites between patients with BRAF-V600E mutation and non-V600E mutations. Patients with V600E mutation were younger than those with non-V600E mutations (p = 0.002). Patients with BRAF V600E mutation showed a poorer outcome than those with non-V600E mutations (23.1 vs. 49.9 months, respectively, p = 0.0024). Lack of CDX2 expression was associated with worse prognosis (mOS: 9.4 m vs. not reached, respectively, p = 0.016). Status of V600E mutation did not affect the mPFS and ORR of first-line or second-line treatment. Conclusion: BRAF V600E mutation defines a distinct subgroup of CRC with worse prognosis. Lack of CDX2 expression is associated with poor OS. Status of V600E mutation did not affect the mPFS of first-line or second-line treatment.

Observational cohort study of clinical outcome in Epstein-Barr virus associated gastric cancer patients.

BACKGROUND: Epstein-Barr virus-associated gastric cancer (EBVaGC) has unique clinicopathologic features and our present understanding of its treatment outcome is limited. Here, we investigated the clinical outcomes of resectable and metastatic EBVaGC cases with regards to their respective treatment. METHODS: We retrieved the data of EBVaGC patients treated at our center from October 2014 to June 2019. The primary endpoint was overall survival (OS). Secondary endpoints were disease-free survival (DFS) for stage I-III patients, progression-free survival (PFS) and objective response rate (ORR) for stage IV patients. RESULTS: Patients classified as stage I-III accounted for 83.7% of the total 197 cases analyzed. Two patients had mismatched repair-deficiency. The 5-year OS rate of the entire cohort was 63.51% [95% (confidence interval (CI): 52.31-72.76%]. Tumor-node-metastasis (TNM) stage and gastric stump cancer were identified as independent prognostic factors for OS. The 3- and 5-year DFS rate for stage I-III patients were 83.72% (95% CI: 75.86-89.19%) and 73.83% (95% CI: 60.39-83.32%), respectively. TNM stage III, neural invasion, lymphovascular invasion, and baseline plasma EBV-DNA positive were correlated with shorter DFS. The ORR and disease control rate (DCR) for metastatic EBVaGC patients to first-line therapy were 29.0% and 90.3% (median PFS: 9.8 months), respectively, and to second-line therapy were 25.0% and 75.0%, respectively. Seven patients received anti-PD1 therapy and had an ORR of 28.5% and a median PFS of 2.8 months. CONCLUSIONS: EBVaGC patients have few metastases, long DFS, and high DCR. TNM stage and gastric stump cancer were independent prognostic factors for OS.

[Effects of Topography, Tree Species and Soil Properties on Soil Enzyme Activity in Karst Regions].

Soil extracellular enzymes are crucial in biogeochemical cycle and ecosystem functioning. Yet uncertainty exists in terms of major determinants on soil extracellular enzyme activity (EEA), especially at calcareous areas. In this study, soil samples (0-15 cm) were collected from different topographic conditions (different slope positions and aspects) and different tree species (Cryptocarya concinna and Eurycorymbus cavaleriei) in a forest located at Mulun natural reserve, a typical karst area. Six hydrolytic enzymes, related to carbon, nitrogen or phosphorus cycling, and soil physiochemical properties were investigated. The effects of topography, tree species and soil properties on soil enzyme activities were analyzed by multi-response permutation procedures (MRPP), redundancy analysis (RDA) and variation partitioning. The enzyme profiles were significantly (P<0.05) separated among the four slope positions but not significantly separated between the two aspects or two tree species according to multi-response permutation procedure (MRPP) analysis. Variation partitioning indicated that topography, tree species and soil properties together explained 55.3% of EEA variation. Soil property was the key factor influencing EEA variation, which explained 44.2% of EEA variation. The result of redundancy analysis (RDA) showed that soil pH, total nitrogen and inorganic nitrogen were the most important variables among the nine soil properties for EEA variation. This study first quantified the effects of small-scale topographic, tree species, and soil properties on soil enzyme activity variation in karst areas. Our results suggest that EEA variation can be well explained by soil properties at a small scale in the karst area.

[Effects of strong reductive process on transformation of heavy metals in protected vegetable soil]. / 强还原过程对设施菜地土壤重金属形态转化的影响.

The application of sewage and manure in protected vegetable cultivation can induce the occurrence of heavy metals contamination. The present research studied the transformation of heavy metals (Cd, Cu, Pb and Zn) by incubating contaminated protected soil with maize straw and then leaching. The results showed that soil pH was significantly decreased, being more evident in maize straw treatment; soil Eh dropped quickly below -280 mV. Maize straw treatment promoted the activation of Cd, Cu, Pb and Zn from soil, and the total percent of oxidizable fraction and residual fraction of Cd, Cu, Pb and Zn declined at 9th day; the amount of Cd, Cu, Pb and Zn in soil reduced 18.1%, 19.0%, 16.1% and 15.7% at 15th day, respectively. Compared to control, maize straw treatment could increase the concentrations of dissolved Cd and Zn, but Cu decreased. The concentration of colloidal-bound Cd and Pb increased, Cu decreased and no significant change occurred in Zn in maize straw treatment. Strong reductive approach could activate heavy metals in protected vegetable soil, increase the risk of heavy metals accumulation in vegetables, and possibly cause water pollution accompanied with soil water mobilization.

[Net ecosystem CO2 exchange and its environmental regulation mechanisms in a reed wetland in the Yellow River Delta of China during the growth season].

By using eddy covariance technique, this paper measured the net ecosystem CO2 exchange (NEE) in a reed (Phragmites australis) wetland in the Yellow River Delta of China during the growth season of 2011, and investigated the variation patterns of the NEE and related affecting factors. The average diurnal variation of the NEE in different months showed a U-type curve, with the maximum net CO2 uptake rate and release rate being (0.44 +/- 0.03) and (0.16 +/- 0.01) mg CO2 x m(-2) x s(-1), respectively. The NEE, ecosystem respiration (R(eco)), and gross primary productivity (GPP) were all higher in vigorous growth season (from July to September) and lower in early growth season (from May to June) and late growth season (from October to November). Both R(eco) and NEE reached their maximum values in August, while GPP reached its peak value in July. During the growth season, the ecosystem CO2 exchange was mainly dominated by photosynthetic active radiation (PAR), soil temperature (T(s)), and soil water content (SWC). There was a rectangular hyperbolic relationship between the daytime NEE and PAR. The nighttime ecosystem respiration (R(eco,n)) was exponentially correlated with the T(s) at 5 cm depth, and the temperature sensitivity of the ecosystem respiration (Q10) was 2.30. SWC and T(s) were the main factors affecting the R(eco,n). During the entire growth season, the reed wetland ecosystem in the Yellow River delta was an obvious carbon sink, with the total net carbon sequestration being 780.95 g CO2 x m(-2).

Labdane diterpenoids and shikimic acid derivatives from Araucaria cunninghamii.

Four new (1-4) and two known compounds (5, 6) were isolated from the aerial parts of Araucaria cunninghamii. By analysis of UV, IR, MS, and NMR, the new compounds were identified as ENT-19-(Z)-coumaroyloxylabda-8(17),13(16),14-triene (1), ENT-19-( E)-coumaroyloxylabda-8(17),13(16),14-triene (2), shikimic acid N-butyl ester (3), and 5-(Z)-coumaroyloxyquinic acid N-butyl ester (4). Compounds 1 and 6 exhibited inhibitory activity against Escherichia coli, and compound 1 also exhibited moderate activity against human leukemia cells (HL-60) and human hepatoma cells (SMMC-7721) with IC50 values of 8.90 and 11.53 µM, respectively.