Seasonal and inter-annual community structure characteristics of zooplankton driven by water environment factors in a sub-lake of Lake Poyang, China

Background

Sub-lakes are important for the maintenance of the ecosystem integrity of Lake Poyang, and zooplankton play an important role in its substance and energy flow.

Methods

A seasonal investigation of zooplankton was conducted in spring (April), summer (July), autumn (October) and winter (January of the following year) from 2012 to 2016 in a sub-lake of Lake Poyang. The aim of the present study was to understand the seasonal dynamics and interannual variation of zooplankton communities and their relationship to environmental factors.

Results

A total of 115 species were identified in all samples in the four years, which comprised of 87 Rotifera, 13 Cladocera and 15 Copepoda. Rotifera was the dominant group in terms of quantity, and its species richness and abundance were significantly higher when compared to Cladocera and Copepoda (P < 0.05), while Cladocera dominated in terms of biomass. The species richness of Rotifera exhibited a significant seasonal difference (P < 0.05). Both the density and biomass of zooplankton revealed significant seasonal differences (P < 0.05). In general, the density and biomass of zooplankton were higher in summer and autumn, when compared to winter and spring. Biodiversity indices were dramatically lower in spring than in the other seasons. The non-metric multidimensional scaling (NMDS) analysis suggested that these zooplankton communities can be divided into three groups: spring community, summer-autumn community, and winter community. The seasonal succession of zooplankton communities did not have interannual reproducibility. In high water level years, the dominant species of zooplankton (Cladocerans and Copepods) in the wet season had a lower density, and the result in low water level years was exactly the opposite. The redundancy analysis revealed that water temperature (WT), conductivity, pH and dissolved oxygen (DO) had significant effects on the zooplankton community.

Conclusions

The community structure of zooplankton has a significant seasonal pattern, but has no interannual repeatability. In high water level years, the dominant species of zooplankton (Cladocerans and Copepods) in the wet season had a lower density, and the result in low water level years was exactly the opposite. The density, biomass and diversity indices of zooplankton were significantly different in different seasons. The present study was helpful in the further understanding of the ecosystem stability of lakes connected with rivers, providing scientific guidance for the protection of lake wetlands.

Microbial Organic Matter Utilization in High-Arctic Streams: Key Enzymatic Controls

In the Arctic, climate changes contribute to enhanced mobilization of organic matter in streams. Microbial extracellular enzymes are important mediators of stream organic matter processing, but limited information is available on enzyme processes in this remote area. Here, we studied the variability of microbial extracellular enzyme activity in high-Arctic fluvial biofilms. We evaluated 12 stream reaches in Northeast Greenland draining areas exhibiting different geomorphological features with contrasting contents of soil organic matter to cover a wide range of environmental conditions. We determined stream nitrogen, phosphorus, and dissolved organic carbon concentrations, quantified algal biomass and bacterial density, and characterized the extracellular enzyme activities involved in catalyzing the cleavage of a range of organic matter compounds (e.g., β-glucosidase, phosphatase, β-xylosidase, cellobiohydrolase, and phenol oxidase). We found significant differences in microbial organic matter utilization among the study streams draining contrasting geomorphological features, indicating a strong coupling between terrestrial and stream ecosystems. Phosphatase and phenol oxidase activities were higher in solifluction areas than in alluvial areas. Besides dissolved organic carbon, nitrogen availability was the main driver controlling enzyme activities in the high-Arctic, which suggests enhanced organic matter mineralization at increased nutrient availability. Overall, our study provides novel information on the controls of organic matter usage by high-Arctic stream biofilms, which is of high relevance due to the predicted increase of nutrient availability in high-Arctic streams in global climate change scenarios.

[Potential value of FDG PET-CT in predicting occult lymph node metastasis in clinical stage ⅠA lung adenocarcinoma]

Objective: To investigate the predictive value of (18)F-FDG PET-CT scan for occult lymph node metastasis in patients with stage ⅠA lung adenocarcinoma. Methods: The image and pathological data of 272 patients with stage ⅠA lung adenocarcinoma from October 2006 to September 2015 were retrospectively analyzed. All patients underwent preoperative (18)F-FDG PET-CT scan followed by lobectomy and systematic lymph node dissection. The correlation between occult lymph node metastasis and the maximum standardized uptake value (SUV(max)) of primary tumor as well as other clinicopathological factors was analyzed to screen the risk factors of occult lymph node metastasis in stage ⅠA lung adenocarcinoma. Results: Occult lymph node metastasis was detected in 50 patients (18.4%), with 24 (8.8%) patients of pN1 involvement and 26 (9.6%) of pN2 involvement. Among the 272 patients enrolled, 39 had pure ground glass nodule, 59 had part-solid nodule and 174 had solid nodule. All patients with pure ground glass nodule or nodule≤1 cm were pN0. For the 233 patients with part-solid and solid nodule, no lymph node metastasis was found in T1a stage (tumor length ≤1 cm). Primary tumor SUV(max) (Z=-5.663, P<0.001), nodule type (χ(2)=21.586, P<0.001), tumor location (χ(2)= 12.790, P< 0.001), histological grade (χ(2)= 22.784, P< 0.001) and visceral pleural invasion (χ(2)=5.357, P=0.021) showed significant differences between occult lymph node metastasis group (pN+ ) and non-lymph node metastasis group (pN0). With SUV(max)=2.405 as cut-off value, the sensitivity and specificity for predicting occult lymph node metastasis were 90.0% and 61.7%, the area under curve was 0.761(95%CI=0.700~0.823), and the negative predictive value was 95.8%. Multivariate analysis revealed that SUV(max) >2.405 (P<0.001), central location (P=0.030) and higher histological grade (P=0.024) were independent predictors of occult lymph node metastasis. Conclusions: For clinical stage ⅠA adenocarcinoma, primary tumor SUV(max) > 2.405, central location and higher histological grade were independent risk factors for occult lymph node metastasis. Systematic lymph node dissection may be avoided in lung adenocarcinoma with pure ground glass density, tumor length ≤1 cm or SUV(max) ≤ 2.405, due to the very low probability of nodal involvement.

Single hormone receptor-positive breast cancer patients experienced poor survival outcomes: a systematic review and meta-analysis

BACKGROUND

The prognostic and clinical significance of single hormone receptor expression in breast cancer has not been clearly established. The goal of this study was to conduct a meta-analysis to compare the clinical outcomes of patients with ER+PR- tumours and ER-PR+ tumours to those of patients with ER+PR+ tumours.

METHODS

A systematic review of the literature was conducted to identify studies that compared the clinical outcome of patients with ER+PR- tumours or ER-PR+ tumours with those of patients with ER+PR+ tumours. A total of 18 studies met the inclusion criteria and included 217,485 women. Standard methods for meta-analysis were used, including fixed-effect models.

RESULTS

Patients with ER+PR- tumours or ER-PR+ tumours had significantly worse DFS (HR 1.60, 95% CI 1.44-1.77 and HR 2.27, 95% CI 1.67-3.09), BCSS (HR 1.43, 95% CI 1.33-1.53 and HR 1.82, 95% CI 1.68-1.98) and OS (HR 1.38, 95% CI 1.28-1.47 and HR 1.48, 95% CI 1.17-1.89) than those of patients with ER+PR+ tumours. In subgroup analyses, patients who had ER+PR- tumours experienced a higher risk of recurrence than patients with ER+PR+ tumours in the HER2- (HR 1.57, 95% CI 1.32-1.87), LN - (HR 2.07, 95% CI 1.44-2.86) and endocrine therapy (HR 1.65, 95% CI 1.45-1.89) subgroup. Patients who had HER2- and ER-PR+ tumours had an increased risk of recurrence compared with patients who had HER2- and ER+PR+ tumours (HR 3.10, 95% CI 1.92-5.10).

CONCLUSIONS

Among patients with hormone receptor-positive breast cancer, patients with either ER+PR- tumours or ER-PR+ tumours have a higher risk of recurrence and a shorter survival time than those with ER+PR+ tumours. Patients with both types of breast cancer need additional or better treatments.

[The effect of trabeculectomy combined with prophylactic sclerotomy as a treatment of late stage juvenile open angle glaucoma and primary congenital glaucoma patients: a primary observational study]

Objective: To evaluate the outcomes of trabeculectomy combined with a new prophylactic sclerotomy in late stage juvenile open angle glaucoma (JOAG) and primary congenital glaucoma (PCG) patients at high risks of intraoperative and postoperative suprachoroidal hemorrhage (SCH). Method: A retrospective case series study. Thirty-three eyes of 28 JOAG patients and 15 eyes of 12 PCG patients with high risk factors for severe choroidal effusion or SCH were enrolled from November 2006 to April 2012 at Eye and ENT Hospital of Fudan University. The standard trabeculectomy accompanied by prophylactic sclerotomy was performed (video attached). Ophthalmic examinations were performed before and after the surgery. Surgical outcome was assessed in terms of intraocular pressure (IOP), best-corrected visual acuity, optic nerve head cup disc ratio, visual field, and complications. All patients were followed up for at least 1 year. Complete success was defined as an IOP ≥6 mmHg (1 mmHg=0.133 kPa) but ≤18 mmHg without medication. Qualified success was defined as an IOP ≥6 mmHg but ≤18 mmHg with local application of medications. Kaplan-Meier survival curves were drawn for the success rate calculation. Results: The mean age of all 40 patients was (13.2±9.4) years old. And among them, 22 patients were male and 18 patients were female. The mean follow-up time was (31.8±15.9) months. At the postoperative 3(rd) year, the complete success rate was 75.8%, and the qualified success rate was 90.0%. In our case series, one eye had expulsive SCH intraoperatively and two eyes had delayed SCH postoperatively. All of them were successfully saved without further surgery and with no significant damage to visual function. Conclusion: Trabeculectomy combined with prophylactic sclerotomy is a promising technique developed to control IOP in late stage JOAG and PCG patients, which provides a potential intervention to reduce severe consequences of massive choroidal effusion or SCH. (Chin J Ophthalmol, 2019, 55: 347-354).

[Application of pegylated recombinant human granulocyte colony-stimulating factor to prevent chemotherapy-induced neutropenia in patients with lymphoma: a prospective, multicenter, open-label clinical trial]

目的

评价聚乙二醇化重组人粒细胞刺激因子（PEG-rhG-CSF）预防淋巴瘤患者化疗后发生中性粒细胞减少症的有效性和安全性。

方法

本研究为多中心、开放、单臂、Ⅳ期临床试验。纳入410例淋巴瘤患者接受多周期化疗并预防性使用PEG-rhG-CSF。主要观察患者各化疗周期Ⅲ/Ⅳ度中性粒细胞减少症和发热性中性粒细胞减少（FN）的发生率，同时观察患者整个化疗期间抗生素的使用率。

结果

①410例患者中，违背入选标准8例（1.95%），失访35例（8.54%），发生不良事件19例（4.63%），出现符合终止研究标准者12例（2.93%），疾病进展或复发15例（3.66%），故最终321例（78.29%）进入符合方案集。②在第1~4个治疗周期，初级预防给予PEG-rhG-CSF后，Ⅳ度中性粒细胞减少症的发生率分别为19.14%（49/256）、12.50%（32/256）、12.18%（24/197）、13.61%（20/147），FN的发生率分别为3.52%（9/256）、0.39%（1/256）、2.54%（5/197）、2.04%（3/147）；次级预防给药后，Ⅳ度中性粒细胞减少症的发生率从61.54%（40/65）降至16.92%（11/65）、18.46%（12/65）、20.75%（11/53），FN的发生率从16.92%（11/65）降至1.54%（1/65）、4.62%（3/65）、3.77%（2/53）。③整个化疗期间接受抗生素治疗的受试者比例为34.39%（141/410）。④与PEG-rhG-CSF相关的不良事件发生率为4.63%（19/410），最常见的不良反应为骨痛[3.90%（16/410）]、乏力（0.49%）和发热（0.24%）。

结论

在淋巴瘤患者化疗过程中，预防性使用PEG-rhG-CSF能够有效降低化疗过程中Ⅲ/Ⅳ度中性粒细胞减少症和FN的发生率，确保淋巴瘤患者接受标准剂量化疗，提高治愈率。

Flow regimes filter species traits of benthic diatom communities and modify the functional features of lowland streams - a nationwide scale study

Changes in land use, climate and flow diversion are key drivers of river flow regime change that may eventually affect freshwater biodiversity and ecosystem functions. However, our knowledge is limited on how the functional features of stream organisms vary along the gradient of hydrological disturbance (i.e. flow regime changes) and how flow regimes mediate the functional features in lowland streams. We analyzed the functional traits of benthic diatoms (unicellular siliceous algae) that are most sensitive and tolerant to flow regime changes along a nationwide scale of 246 sites in Denmark. We combined RLQ and fourth-corner analyses to explore the co-variation between hydrological variables (R table) and species traits (Q table), constrained by the relative abundance of each species (L table) as observed in each of the sampling sites. Further, we examine the relationships between functional features (i.e., functional redundancy and diversity) and hydrological variables by multivariate statistical analyses. Results show that species turnover with displacement of sensitive species by tolerant species was the dominating process in benthic diatom communities during high flow disturbances. Functional features, as indicated by functional diversity and redundancy indices, were mediated mainly by high and low flow magnitude. Median daily flow magnitude shows a consistent positive relationship with functional redundancy and richness indices indicating that larger streams are more resilient to flow perturbations. In addition flow regime changes are less important than median daily flow magnitude and show inconsistent correlation to functional features likely due to the interaction of multiple environmental stressors. Our study highlights the robustness of trait-based approaches for identifying flow regime changes in streams, and strongly suggests that biodiversity conservation and water resource management should focus on protecting natural base flow in headwater streams and generally reduce flow regulation for sustaining stream ecosystems under future global changes.

How successful are the restoration efforts of China's lakes and reservoirs?

China has made considerable efforts to mitigate the pollution of lakes over the past decade, but the success rate of these restoration actions at a national scale remains unclear. The present study compiled a 13-year (2005-2017) comprehensive dataset consisting of 24,319 records from China's 142 lakes and reservoirs. We developed a novel Water Quality Index (WQI-DET), customized to China's water quality classification scheme, to investigate the spatio-temporal pollution patterns. The likelihood of regime shifts during our study period is examined with a sequential algorithm. Our analysis suggests that China's lake water quality has improved and is also characterized by two WQI-DET abrupt shifts in 2007 and 2010. However, we also found that the eutrophication problems have not been eradicated and heavy metal (HM) pollution displayed an increasing trend. Our study suggests that the control of Cr, Cd and As should receive particular attention in an effort to alleviate the severity of HM pollution. Priority strategies to control HM pollution include the reduction of the contribution from mining activities and implementation of soil remediation in highly polluted areas. The mitigation efforts of lake eutrophication are more complicated due to the increasing importance of internal nutrient loading that can profoundly modulate the magnitude and timing of system response to external nutrient loading reduction strategies. We also contend that the development of a rigorous framework to quantify the socioeconomic benefits from well-functioning lake and reservoir ecosystems is critically important to gain leeway and keep the investments to the environment going, especially if the water quality improvements in many Chinese lakes and reservoirs are not realized in a timely manner.

[Clinicopathologic and molecular features of myoepithelial tumors of salivary glands]

Objective: To investigate the clinicopathological, and molecular characteristics of myoepithelial tumors (MTs) of salivary glands. Methods: A total of 37 MTs cases including 13 malignant epithelial tumors (MMTs) and 24 benign epithelial tumors (BMTs) of salivary glands were identified from the archives of the Department of Pathology, General Hospital of Eastern Theater Command, dating from 2006 to 2016. Clinical features, histological patterns, immunohistochemical characteristics and status of EWSR1 gene rearrangement by fluorescence in situ hybridization (FISH) analysis were reviewed in all cases. Results: Clinically, 37 MTs cases mainly occurred in the parotid glands, when most of the patients presented with painless masses. Of the 13 MMTs cases, male to female ratio was 7∶6, and the median age was 62 years old. Of the 24 BMTs cases, male to female ratio was 5∶7, and the median age was 54 years old. Immunohistochemically, 37 MTs cases were positive for CKpan, and at least one myoepithelial marker. Twenty six of 37 MTs cases were analyzable for the EWSR1 gene break by FISH. Based on the previous evaluation criterion, the EWSR1 translocation was detected in 4 cases of 11 MMTs, and 4 cases of 15 BMTs. According to the main histological composition of tumor cells, 4 EWSR1-positive MMTs covered 2 clear-cell cases and 2 epithelioid-cell cases, when 4 EWSR1-positive BMTs covered 2 clear-cell cases, 1 plasmacytoid-cell case, and 1 spindle-cell case. Conclusions: Males and females are affected equally. MTs express immunoreactivity for CKpan, and at least one myoepithelial marker. The EWSR1 rearrangement is present in a subset of MTs, with variable morphological characteristics, and has no statistical significance on clinical behavior.

[Comparison of parameters for diffusion-weighted intravoxel incoherent motion imaging in lung cancer patients with different histopathological subtypes]

Objective: To explore the intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) model in lung cancer patients with different histopathological subtypes. Methods: A total of 105 patients were recruited, including 68 cases of adenocarcinoma, 22 cases of squamous carcinoma and 15 cases of small cell carcinoma. All patients underwent magnetic resonance examination consisting of axial IVIM-DWI sequence on a 3.0 T whole body scanner, then the standard ADC (sADC), diffusion coefficient (D), pseudo-diffusion coefficient(D(*)), perfusion fraction (f), distributed diffusion coefficient (DDC) and water diffusion heterogeneity index (α) were calculated for each lesion within the IVIM-DWI model. Results: Mean sADC values were (1.45±0.26) ×10(-3)mm(2)/s, (1.36±0.48) ×10(-3)mm(2)/s and (1.35±0.40) ×10(-3)mm(2)/s for adenocarcinoma, squamous carcinoma and small cell carcinoma, respectively. Mean f values were (59.75±16.37) %, (47.41±18.69) % and (48.96±19.88) % for adenocarcinoma, squamous carcinoma and small cell carcinoma, respectively. Mean α values were 0.72±0.13 for adenocarcinoma, 0.62±0.12 for squamous carcinoma, and 0.63±0.11 for small cell carcinoma, respectively. Statistical analyses indicated that the sADC, f and α values among different histopathological subtypes were significantly different (P<0.05), while there was no significant difference in D, D(*) and DDC values (P>0.05). Furthermore, the comparison showed that the sADC, f and α values of patients with adenocarcinoma were significantly higher than those with squamous carcinoma or small cell carcinoma (P<0.05), whereas there was no significant difference between squamous carcinoma group and small cell carcinoma group (P>0.05). Conclusions: The sADC, f and α values derived from the IVIM-DWI model can be used for comprehensive non-invasive evaluation of diffusion, perfusion and heterogeneity of microenvironment in lung cancer patients. And the IVIM-DWI model may be a promising tool for predicting histopathological subtypes of lung cancer.

[Mediating effect of work engagement between job stress and depressive symptoms in State Grid employees]

Objective: To explore the relationship between job stress, work engagement and depressive symptoms of State Grid workers, and to analyze the mediating effect of work engagement between job stress and depressive symptoms. Methods: A cross-sectional survey was conducted to investigate 845 employees from a State Grid company, using the brief job stress questionnaire, the Patient Health Questionnaire (PHQ-9) and 9-item Utrecht Work Engagement Scale (UWES-9) in March 2017. Results: The average score of work engagement was 4.49±1.42, the mean value of job stress was 1.15±0.33, the average score of depressive symptoms was 6.44±4.30, and the positive rate of depressive symptoms was 66.9%.There was a negative correlation between work engagement with both job stress and depressive symptoms (r=-0.193, -0.397, both P<0.01) , and job stress was positively correlated with depressive symptoms (r=0.260, P<0.01) . The relationship between job stress and depressive symptoms was partly mediated by work engagement, and the mediating effect accounted for 27.2% of the total effect. Conclusion: The work engagement of State Grid staff acts as the mediator between job stress and depressive symptoms, alleviating the depressive symptoms caused by job stress.

[Association between Long Working Hours and Job Stress and Depression among Employees from a State Grid Company]

Objective: This study was to understand the current situation of long working hours and identify the association of long working hours and job stress and depression among workers from one district company of state grid. Methods: The project was done with the cross-sectional survey. All questionnaires were completed by self-administered with informed consent. Employees' weekly working hours was reported by themselves; Using the PHQ-9 scale to assess depression, the JDC Model to evaluate job stress, and SPSS software to analyze data, the single factor chi-square test and multivariate Logistic analysis were performed to identify the association between long working hours and job stress, depression. Results: there were 35.3 percent employees with over 44 hours a week. The association between increasing weekly working hours and job stress and depression was statistically significant. Compared to the reference group (≤44 h) , for those who worked more than 44 hours per week, the odds ratio of job stress was 2.02 (95%CI=1.27-3.23) times increased, and the odds ratio of depression was 1.60 (95%CI=1.01-2.55) times increased, especially for those (≥60 h) , the odds ratio was 3.69 (95%CI=1.45-9.41) and 2.76 (95%CI=1.09-7.03) respectively. Conclusion: Long working hours can significantly increase the risk of job stress and depression among workers. When their weekly working hours exceeds 60, long working hours will be the independent risk factor for both job stress and depression.