Circular RNA PTK2 Accelerates Cell Proliferation and Inhibits Cell Apoptosis in Gastric Carcinoma via miR-139-3p.

BACKGROUND: Gastric carcinoma (GC) is one of the most common malignant tumors. Although increasing studies have indicated that circular RNAs function as ideal biomarkers for multiple cancers, only a few researches elucidated the correlation between circular RNA PTK2 (circPTK2) and human cancers. AIM: To further explore the expression status, biological function, and regulatory mechanism of circPTK2 in GC. METHODS: Bioinformatics analysis and function or mechanism experiments including RT-qPCR, flow cytometry, Western blot, luciferase reporter assay, and xenografts assays were applied to investigate the function of circPTK2 and miR-139-3p. RESULTS: High expression of circPTK2 was presented in GC tissues and cells. The circPTK2 knockdown notably suppressed cell proliferation and promoted cell apoptosis in GC. In mechanism, circPTK2 served as a sponge of miR-139-3p. Inhibition of miR-139-3p could reverse circPTK2 silence-mediated effects on GC cell proliferation and apoptosis. Furthermore, the xenograft tumor model was established to investigate the role of circPTK2 in GC tumor growth. Experimental results delineated that the reduction in tumor growth in response to circPTK2 knockdown was partly recovered by miR-139-3p inhibitor. CONCLUSIONS: CircPTK2 promotes GC development by sponging miR-139-3p, which may function as an effective gene target for managing GC.

Stress responses in expressions of microRNAs in mussel Mytilus galloprovincialis exposed to cadmium.

MicroRNAs (miRNAs) are known to have complicated functions in aquatic species, but little is known about the role of miRNAs in mollusk species under environmental stress. In this study, we performed small RNA sequencing to characterize the differentially expressed miRNAs in different tissues (whole tissues, digestive glands, gills, and gonads) of blue mussels (Mytilus galloprovincialis) exposed to cadmium (Cd). In summary, 107 known miRNAs and 32 novel miRNAs were significantly (p < 0.01) differentially expressed after Cd exposure. The peak size of miRNAs was 22 nucleotides. Target genes of these differentially expressions of miRNAs related to immune defense, apoptosis, lipid and xenobiotic metabolism showed significant changes under Cd stress. These findings provide the first characterization of miRNAs in mussel M. galloprovincialis and expressions of many target genes in response to Cd stress.

Effects of a Perioperative Safety Checklist on Postoperative Complications Following Surgery for Gastric Cancer: A Single-Center Preliminary Study.

Objective. A Perioperative Safety Checklist (PSC) for gastric cancer (GC) was established to evaluate the effects of PSC on the clinical outcomes of GC. Methods. This single-center preliminary observational study conducted at a tertiary referral hospital included patients with GC who underwent surgery from January 1, 2016, to June 30, 2016, treated without PSC (allocated to the control group) and those who underwent surgery between January 1, 2017, and June 30, 2017, managed according to the PSC designated as the PSCGC (Perioperative Safety Checklist for Gastric Cancer) group. Results. Overall, 1072 cases were enrolled, 556 cases in PSCGC group and 526 cases in control group. After matching, there were 474 patients in each group. PSC intervention led to significant reductions of the incidence of postoperative intestinal fistula formation (P = .034), the incidence of unplanned secondary surgery (P = 0.039), and the total hospitalization expenses (P < .001). Total completion rate of all 14 checklists items was 79.1%. Intraoperative blood loss in the complete and partial implementation groups was significantly lower than the complete nonimplementation group (P = .002), whereas hospitalization cost showed an opposite trend, which was significantly higher in the incomplete nonimplementation group (P = .015). Conclusion. PSC implementation was associated with a decreased incidence of gastrointestinal fistula formation, unplanned secondary surgery, and hospitalization cost in patients with GC. However, it had no effect on the in-hospital mortality, the incidence of postoperative complications during hospitalization (ie, incision complications and lung infections), unplanned secondary admission, and the duration of postoperative hospital stay.

Surgical and Long-Term Survival Outcomes After Laparoscopic and Open Total Gastrectomy for Locally Advanced Gastric Cancer: A Propensity Score-Matched Analysis.

BACKGROUND: To compare the surgical and long-term survival outcomes of laparoscopic and open total gastrectomy (OTG) for locally advanced gastric cancer (AGC). METHODS: We retrospectively evaluated 308 and 900 patients in pathological locally AGC who underwent laparoscopic total gastrectomy (LTG) or OTG between June 2008 and December 2014. We compared surgical and long-term outcomes between the two groups using propensity score matching method. RESULTS: The LTG group showed a longer operation time (261.42 vs. 171.00 min, P = 0.001), less blood loss (185.47 vs. 217.84 ml, P = 0.000), earlier time to first flatus (3.47 vs. 4.12 days, P = 0.000), earlier time to start liquid diet (3.76 vs. 4.27 days, P = 0.000), and shorter postoperative hospital stay (7.56 vs. 8.22 days, P = 0.007). The overall complication rate was 15.2% in the LTG group and 17.2% in the OTG (P = 0.503). No significant difference was observed in overall survival (OS) and disease-free survival (DFS) between LTG and OTG (60.5% vs. 57.1%, P = 0.337; 57.4% vs. 54.4%, P = 0.341). CONCLUSIONS: Compared to OTG, LTG provides surgical benefits and comparable survival outcomes for patients with locally AGC.

Laparoscopy-assisted distal gastrectomy versus laparoscopy-assisted total gastrectomy with D2 lymph node dissection for middle-third advanced gastric cancer.

BACKGROUND: There still remains controversy for the choice of resection extent for gastric cancer involving the middle-third of the stomach. The aim of this study was to compare the technical feasibility and long-term outcomes of laparoscopy-assisted distal gastrectomy (LADG) versus laparoscopy-assisted total gastrectomy (LATG) for middle-third advanced gastric cancer (AGC) and to determine which is the optimal surgical procedure. METHODS: For this study, clinical data for 379 patients who underwent LADG or LATG with D2 lymph node dissection between April 2005 and June 2014 were analyzed retrospectively. The short- and long-term outcomes were compared between the propensity score-matched groups. RESULTS: The LADG group had a significantly shorter operating time (212.74 vs. 241.79 min, P < 0.001), less estimated blood loss (114.38 vs. 181.51 ml, P = 0.000), shorter first flatus and postoperative hospital stay. Additionally, the total cost of hospitalization was significantly higher in the LATG group than LADG group (71187.58 vs. 65783.25 RMB, P = 0.000). There were no significant differences in postoperative complications rate between the LADG group and the LATG group. The 5-year overall survival (OS) rates were 64.4% in the LADG group and 61.0% in the LATG group (P = 0.548). The resection extent was not an independent prognostic factor for the OS. CONCLUSIONS: LADG with D2 nodal dissection is a feasible treatment strategy for middle-third AGC with better short-term outcomes and similar long-term survival rates compared with LATG. We recommended that DG should be the optimal surgical procedure for middle one-third AGC under the premise of negative proximal resection margin.

Differential metabolic responses in three life stages of mussels Mytilus galloprovincialis exposed to cadmium.

Cadmium (Cd) is one of the most important metal contaminants in the Bohai Sea. In this work, NMR-based metabolomics was used to investigate the toxicological effects of Cd at an environmentally relevant concentration (50 µg L-1) in three different life stages (D-shape larval, juvenile and adult) of mussels Mytilus galloprovincialis. Results indicated that the D-shape larval mussel was the most sensitive life stage to Cd. The significantly different metabolic profiles meant that Cd induced differential toxicological effects in three life stages of mussels. Basically, Cd caused osmotic stress in all the three life stages via different metabolic pathways. Cd exposure reduced the anaerobiosis in D-shape larval mussels and disturbed lipid metabolism in juvenile mussels, respectively. Compared with the D-shape larval and juvenile mussels, the adult mussels reduced energy consumption to deal with Cd stress.

Proteomic and metabolomic responses in D-shape larval mussels Mytilus galloprovincialis exposed to cadmium and arsenic.

Cadmium (Cd) and arsenic (As) are the main metal/metalloid contaminants in the coastal environments of the Bohai Sea, China. In this work, a combined proteomic and metabolomic approach was applied to investigate the biological effects of Cd and As (V) in the early life stage (D-shape larvae) of mussel Mytilus galloprovincialis. Results indicated that Cd was a potential immune toxicant to D-shape larval mussel because of the numerous proteomic responses related to immune system. Additionally, Cd induced oxidative stress, cellular injury and disturbance in nucleic acid metabolism in D-shape larval mussels. However, only two identified proteins were significantly altered in As (V)-treated group, suggesting that D-shape larval mussel was less sensitive to As (V) than to Cd at protein level. These two proteins in response to As (V) suggested that As (V) influenced anti-oxidative system and cell proliferation in D-shape larval mussels. Metabolic responses indicated that Cd and As (V) induced disturbances in osmotic regulation and energy metabolism in D-shape larval mussels via different metabolic pathways. In addition, Cd reduced lipid metabolism as well. This work demonstrated that a combination of proteomics and metabolomics could provide an insightful view in the biological effects of pollutants in mussel M. galloprovincialis at an early life stage.

Proteomic responses reveal the differential effects induced by cadmium in mussels Mytilus galloprovincialis at early life stages.

Cadmium (Cd) has become an important metal contaminant and posed severe risk on the organisms in the coastal environments of the Bohai Sea. Marine mussel Mytilus galloprovincialis is widely distributed along the Bohai coast and consumed as seafood by local residents. Evidences indicate that the early stages of marine organisms are more sensitive to metal contaminants. In this study, we applied two-dimensional electrophoresis-based proteomics to characterize the biological effects of Cd (50 µg L(-1)) in the early life stages (D-shape larval and juvenile) of mussels. The different proteomic responses demonstrated the differential responsive mechanisms to Cd exposure in these two early life stages of mussels. In details, results indicated that Cd mainly induced immune and oxidative stresses in both D-shape larval and juvenile mussels via different pathways. In addition, the significant up-regulation of triosephosphate isomerase and metallothionein confirmed the enhanced energy demand and mobilized detoxification mechanism in D-shape larval mussels exposed to Cd. In juvenile mussels, Cd exposure also induced clear apoptosis. Overall, this work suggests that Cd is a potential immune toxicant to mussel M. galloprovincialis at early life stages.

Utilization Potential of Aerated Concrete Block Powder and Coffee Grounds Ash in Green-Growing Concrete.

The purpose of this research is to investigate the utilization potential of recycled powder made from spent coffee grounds (SCGs) and aerated concrete blocks (ACBs) in green-growing concrete. The green-growing concrete is prepared using ACB powder and SCG ash as raw materials instead of 5%, 15%, and 25% and 5%, 10%, and 15% cement, respectively. Then, the two raw materials are compounded with the optimal content. The compressive strength and alkalinity of green-growing concrete at 7d and 28d and the frost resistance after 25 freeze-thaw cycles at 28d are studied. The results showed that the optimum content of ACB powder and SCG ash was 5%. Replacing 5% cement with recycled powder could improve the strength of concrete. The alkalinity of concrete containing ACB powder gradually increased, while the alkalinity of concrete containing SCG ash gradually decreased. The alkalinity of ACB-SCG powder was lower than that of ACB powder but slightly higher than that of SCG ash. The frost resistance of concrete containing ACB powder decreased gradually, and the frost resistance of concrete containing SCG ash increased first and then decreased greatly. The frost resistance of ACB-SCG powder could neutralize that of ACB powder and SCG ash.

Transcriptomic analysis reveals interactive effects of polyvinyl chloride microplastics and cadmium on Mytilus galloprovincialis: Insights into non-coding RNA responses and environmental implications.

Despite increasing concerns regarding the interactions of microplastic and heavy metal pollution, there is limited knowledge on the molecular responses of marine organisms to these stressors. In this study, we used whole-transcriptome sequencing to investigate the molecular responses of the ecologically and economically important bivalve Mytilus galloprovincialis to individual and combined exposures of environmentally relevant concentrations of PVC microplastics and cadmium (Cd). Our results revealed distinct transcriptional changes in M. galloprovincialis, with significant overlap in the differentially expressed genes between the individual and combined exposure groups. Genes involved in cellular senescence, oxidative stress, and galactose metabolism were differentially expressed. Additionally, key signaling pathways related to apoptosis and drug metabolism were significantly modulated. Notably, the interaction of PVC microplastics and Cd resulted in differential expression of genes involved in drug metabolism and longevity regulating compared to single exposures. This suggests that the interaction between these two stressors may have amplified effects on mussel health. Overall, this comprehensive transcriptomic analysis provides valuable insights into the adaptive and detrimental responses of M. galloprovincialis to PVC microplastics and Cd in the environment.

Experimental Evaluation of the Properties of Recycled Aggregate Pavement Brick with a Composite Shaped Phase Change Material.

Brick waste makes up a significant part of the solid waste that is generated from building demolition globally. The disposal of this waste consumes land, causes environmental pollution, and is a waste of resources. In order to use this construction waste and increase its functionality, two types of stable-shape PEG-400/SiO2 composite shaped PCM and Tet/SiO2 composite shaped PCM were studied and added to recycled aggregate pavement bricks, and two new types of composite shaped PCM recycled aggregate pavement bricks were created. SEM, DSC, TGA, and other test methods found the two PCMs to be successfully adsorbed by SiO2, and the setting effect of PEG-400/SiO2 was found to be better than that of Tet/SiO2. The physicochemical properties of both composite shaped PCMs remained stable within the TGA test temperature range. The prepared PCM was added to the recycled aggregate pavement brick. A comprehensive analysis of the properties of the composite shaped PCM recycled orthopedic pavement brick found the compressive strength and flexural strength of Tet/SiO2 PCM recycled aggregate pavement brick to be significantly higher than those of PEG-400/SiO2 PCM recycled aggregate pavement brick. With a recycled aggregate content of 60% and a compound shaped PCM content of 5%, the 28-day strength of the recycled aggregate pavement brick was found to be higher than that of the recycled aggregate pavement brick with a recycled aggregate content of 70% and a compound shaped PCM content of 10%. This study provides reference for the optimization and upgrading of the thermal storage performance of composite shaped PCM in practical applications, and is of great significance for promoting thermal energy storage development and expanding its application range.

Development and External Validation of Safe Discharge Criteria After Radical Gastrectomy.

AIM: Enhanced recovery after surgery (ERAS) gradually shortens the length of stay but increases the rate of unplanned readmission after discharge. Currently, objective discharge criteria for patients after radical gastrectomy is lacking. This study aimed to construct and validate a nomogram for estimation of the possibility of safe discharge on the fifth-day post radical gastrectomy. METHODS: We enrolled 496 consecutive patients undergoing radical gastrectomy as the development cohort. After the fifth day of surgery, patients were assigned to the postoperative complication group and no postoperative complication group. Multivariate logistic regression analyses were performed for both groups. Then, we constructed the risk prediction model of postoperative severe complications (PSCs) and applied it to evaluate whether the patient could be discharged safely. The external validation cohort comprised 245 patients, whom we used to evaluate the capability of our model to predict the risk of PSCs. The primary measure was the negative predictive rate (NPR) and the area under the curve (AUC). RESULTS: Through multivariate analysis, gender, maximum body temperature on the 4th postoperative day (POD4), oral intake and ambulatory duration on POD4, the proportion of neutrophils (≥75% or <75%) and pain score (≥4 or <4) on POD5, and defecation with 5 days after the procedure (yes or no) were identified as independent predictors for PSCs. Upon incorporation of these variables, the nomogram demonstrated a good NPR of 0.957 and 0.916 and AUC of 0.918 and 0.719 in the two cohorts, respectively. With a nomogram score of 110, patients were stratified into low and high risk of PSCs. CONCLUSION: The nomogram demonstrated good predictive potential for low-risk patients. It could serve as an objective safe discharge approach for patients after the fifth day of radical gastrectomy.

Metal pollution and its biological effects in swimming crab Portunus trituberculatus by NMR-based metabolomics.

Metal pollution in the Bohai Sea in China has posed a potential risk on marine organisms. In this work, crabs (Portunus trituberculatus) were sampled from four sites, namely a reference (site 3934) and three metal-polluted (sites 6151, 6351, and 3562) sites, located in the Bohai Sea. Metal concentrations in crab gill tissues were measured using inductively coupled plasma mass spectrometry. Cu, Zn, and Cd in crab samples from S3562 presented the highest concentrations. Particularly, Cu concentration exceeded the marine biological quality standard II. Cd contents in crab samples from all metal-polluted sites exceeded the marine biological quality standard I. Nuclear magnetic resonance-based metabolomics indicated metal pollution-induced immune stresses in crab samples from all metal-polluted sites. Metal pollution in S6151 and S6351 disturbed energy metabolism through differential pathways. For crab samples from S3562, the metabolic profile suggested that metal pollution mainly induced osmotic stress.

Profiling of microRNAs and mRNAs in marine mussel Mytilus galloprovincialis.

MicroRNAs (miRNAs) are a class of noncoding RNA molecules containing 18-24 nucleotides, and those with conserved structures are able to regulate the expression of eukaryotic genes by inhibition or enhancement of mRNA translation. However, miRNAs of the blue mussel, Mytilus galloprovincialis have not been reported. M. galloprovincialis is a primary species distributed along coastal zones worldwide. To reveal the repertoire of miRNAs in M. galloprovincialis, we constructed small RNA libraries prepared from three different mussels, which were then sequenced by Solexa deep sequencing technology. A total of 32,836,817, 33,359,113 and 33,093,562 clean reads from the tissues of the three M. galloprovincialis were obtained. Based on sequence similarities and hairpin structure predictions, 137 M. galloprovincialis miRNAs (mg-miRNA) were identified. Among the mg-miRNAs, 104 were conserved across species, whereas 33 might be novel and specific for M. galloprovincialis. Some of the mg-miRNAs, such as let-7 and the miR-100 family are playing key roles in many metabolic pathways and are worthy of further study. By performing a whole genome-scale characterization of mg-miRNAs and proposing their potential functions, these results provide a foundation for understanding the biological processes of the blue mussel, M. galloprovincialis.

Effect Of Surgical Safety Checklists On Gastric Cancer Outcomes: A Single-Center Retrospective Study.

AIMS: Surgery is the primary treatment option for patients with gastric cancer, however the rate of postoperative complications are still high. The implementation of surgical safety checklists (SSCs) has been shown to reduce morbidity and mortality. This study aimed to evaluate the effect of SSCs on the clinical outcomes of gastric cancer. METHODS: A total of 881 gastric cancer patients who underwent D2 gastrectomy from May 2009 to April 2011 in a large teaching hospital in China were included in this retrospective study. Patients were matched and divided into the control group (SSC nonimplementation) and intervention group (SSC implementation). The outcomes including intraoperative condition, postoperative complications, and prognosis were then compared between the groups. RESULTS: The control group comprised 414 patients (47.0%), and the intervention group included 467 patients (53.0%). Patients in the intervention group had a significantly shorter length of postoperative stay (P < 0.001). Operation time, blood loss, blood transfusion, and hospital charges were comparable between the two groups (all P > 0.05). SSC was not associated with postoperative complications (all P > 0.05). Overall survival was also comparable between patients in the two groups (P > 0.05). CONCLUSION: The implementation of an SSC was associated with a decreased length of postoperative stay in gastric cancer patients following D2 gastrectomy but did not significantly affect the other outcomes.

Laparoscopic versus open gastrectomy for high-risk patients with gastric cancer: A systematic review and meta-analysis.

BACKGROUND: It is still remains unclear whether high-risk patients with gastric cancer can benefit from the application of laparoscopic gastrectomy (LG). The aim of this systematic review was to evaluate the surgical and long-term outcomes after LG and open gastrectomy (OG) for high-risk patients with gastric cancer. METHODS: We performed a systematic literature search in various databases from January 1994 to June 2018. Patients who had≥1 of the following conditions were defined as high-risk patients: (1) age≥70 years; (2) BMI≥30 kg/m2; (3) ASA (American Society of Anesthesiologists) grade≥3; or (4) clinical T4 stage (cT4). The results were analyzed according to predefined criteria. RESULTS: In the present meta-analysis, the outcomes of 12 non-randomized controlled studies enrolling 1651 patients (873 in the LG group and 778 in the OG group) were pooled. The estimated blood loss was significantly lower in the LG group than those in the OG group (P < 0.01). There was no significant difference between two groups in operative time (P = 0.17) and number of harvested lymph nodes (P = 0.21). In the LG group, the time to flatus (P < 0.01), time to food intake (P < 0.01), and postoperative hospital stay (P < 0.01) were significantly shorter than those in the OG group. A lower overall postoperative complication rate was observed in the LG group (P < 0.01). The incidence of surgical (P < 0.01) and non-surgical (P < 0.01) complication was significantly lower in the LG group than that in the OG group. The pooled analysis showed no significant difference in overall survival (OS) between LG and OG groups (P = 0.98). CONCLUSIONS: LG can be a safe and feasible procedure for high-risk patients with gastric cancer.

Impact of climate factors on height growth of Pinus sylvestris var. mongolica.

Tree height growth is sensitive to climate change; therefore, incorporating climate factors into tree height prediction models can improve our understanding of this relationship and provide a scientific basis for plantation management under climate change conditions. Mongolian pine (Pinus sylvestris var. mongolica) is one of the most important afforestation species in Three-North Regions in China. Yet our knowledge on the relationship between height growth and climate for Mongolian pine is limited. Based on survey data for the dominant height of Mongolian pine and climate data from meteorological station, a mixed-effects Chapman-Richards model (including climate factors and random parameters) was used to study the effects of climate factors on the height growth of Mongolian pine in Zhanggutai sandy land, Northeast China. The results showed that precipitation had a delayed effect on the tree height growth. Generally, tree heights increased with increasing mean temperature in May and precipitation from October to April and decreased with increasing precipitation in the previous growing season. The model could effectively predict the dominant height growth of Mongolian pine under varying climate, which could help in further understanding the relationship between climate and height growth of Mongolian pine in semiarid areas of China.

Surgical and long-term oncologic outcomes of laparoscopic and open gastrectomy for serosa-positive (pT4a) gastric cancer: A propensity score-matched analysis.

BACKGROUND: To date, it has been unclear whether laparoscopic gastrectomy (LG) is suitable for patients with serosa-positive (pT4a) gastric cancer. The purpose of this study was to compare the surgical and long-term oncologic outcomes of LG and open gastrectomy for pT4a gastric cancer. METHODS: We prospectively collected data from 987 patients with pathological confirmed pT4a gastric cancer who underwent LG or OG at our institution between June 2009 and May 2015. A 1:1 matched propensity score matching (PSM) analysis was performed to reduce confounding bias. The primary outcome was 5-year overall survival (OS). RESULTS: After PSM, a well-balanced cohort of 202 pairs patients was analyzed. The LG group showed a longer operation time (261.42 vs. 171.00 min, P = 0.001), less blood loss (185.47 vs. 217.84 ml, P = 0.000), and shorter postoperative hospital stay (7.56 vs. 8.22 days, P = 0.007). The overall complication rate was 14.4% in the LG group and 16.3% in the OG group (P = 0.581). The minor (grade II) and severe (grade ≥ IIIa) complication rates were similar (LG, 6.9% vs. OG, 9.9%, P = 0.282; LG, 7.4% vs. OG, 6.4%, P = 0.695, respectively). The LG and OG groups showed similar survival 5-year OS and 5-year Disease-free survival (DFS) rates (44.6% vs. 42.1%, P = 0.403; 40.1 vs. 37.6%, P = 0.321, respectively). The recurrence rate and pattern did not differ between the two groups during the follow-up stage (P > 0.05). CONCLUSIONS: For patients with pT4a gastric cancer, LG with D2 lymph node dissection can be a safe and feasible procedure in terms of surgical and long-term oncologic outcomes.

Upregulated histamine receptor H3 promotes tumor growth and metastasis in hepatocellular carcinoma.

Histamine receptor H3 (HRH3) is mainly expressed in the central nervous system, where it is involved in the regulation of the release of various neurotransmitters in the brain. Recent studies have demonstrated that the expression of HRH3 is upregulated in several types of cancer. However, the functional effect of HRH3 on tumor progression remains largely unknown, particularly in hepatocellular carcinoma (HCC). In the present study, the expression of HRH3 in 96 HCC patients was first evaluated, and its clinical significance was analyzed. Subsequently, the functional roles of HRH3 in HCC growth and metastasis were systematically explored in vitro and in vivo using its agonist (imetit) or antagonist (clobenpropit). It was observed that HRH3 was significantly upregulated in HCC tissues, while its expression was significantly associated with recurrence­free survival and overall survival in HCC patients. Functional experiments also demonstrated that HRH3 upregulation facilitated the growth and metastasis of HCC cells by inducing the formation of lamellipodia. These findings revealed that HRH3 serves an important role in the growth and metastasis of HCC cells, which provides experimental evidence supporting the application of HRH3 as a potential therapeutic target in HCC treatment.

Changes in soil organic carbon and its influencing factors in the growth of Pinus sylvestris var. mongolica plantation in Horqin Sandy Land, Northeast China.

The change of soil organic carbon and its influencing factors after afforestation in sandy land should be taken into account. Here, the factors would be revealed which would influence the SOC dynamics to a depth of 100 cm during the development of Mongolian pine plantations in Horqin sandy land, northeast China. The chronosequence method was used to quantify the change of SOC in vertical distribution and influencing factors following conversion grassland to Pinus sylvestris var. mongolica forest in semi-arid sandy land, northeast China. Then the traditional statistical approaches were used to assessed the influence of the identified factors. Stand age played a major role in SOC dynamics. It took 38 years for SOC in 0-10 cm layer to recover to its initial level after afforestation, and 46 years for 10-20 cm layer. SOC accumulation increased with the age of Mongolian pine plantation. Over-mature forest fully embodied the advantage of SOC accumulation. In addition, the changes of SOC in 0-10 cm layer were also affected by TN, TP, TK and soil moisture, and those below 10 cm soil layers were related to the effects of TN, TP, TK, BD and CS.