[Analysis of Influencing Factors of Chlorophyll-a in Lake Taihu Based on Bayesian Network].

Global warming has aggravated the problem of lake eutrophication. As a typical large, eutrophic, shallow lake in China, the issue of cyanobacterial harmful algal blooms (cyanoHABs) was particularly prominent in Lake Taihu. We took Lake Taihu as the study area, using the meteorological (temperature, wind speed, rainfall, and sunshine hours), water quality (total nitrogen, total phosphorus, conductivity, pH, and chemical oxygen demand), and biological (chlorophyll-a in phytoplankton) monitoring data from 1992 to 2020. We built a simulation model of chlorophyll-a based on the Bayesian network model with continuous variables to study the chlorophyll-a level of Lake Taihu under different meteorological and water quality conditions. The 75th percentile of chlorophyll-a concentration was used as the threshold to judge the risk of cyanobacterial bloom. When the probability of chlorophyll-a concentration below this threshold was greater than 75%, it was regarded as "low risk" of cyanobacterial bloom outbreak. The results showed that the average level of "temperature wind ratio" (ratio of air temperature to wind speed) in spring was 6.67℃·s·m-1, and the probability of high chlorophyll-a was less than 75% when the total phosphorus concentration was less than 0.130 mg·L-1. The average "temperature wind ratio" level in summer was 10.52℃·s·m-1, and the probability of high chlorophyll-a was less than 75% when the total phosphorus concentration was less than 0.257 mg·L-1. The average level of total phosphorus concentration in autumn was 0.154 mg·L-1, and the probability of high chlorophyll-a was less than 75% when the "temperature wind ratio" was less than 6.30℃·s·m-1. Based on the above research, the chlorophyll-a model constructed by the Bayesian network model with continuous variables was further used to simulate the nutrient control objectives under different climate change backgrounds. In order to control chlorophyll-a in Lake Taihu at the:"low risk" level of cyanoHABs, the target concentration thresholds of total phosphorus needed to be controlled under the climate level background from 1992 to 2000, 2001 to 2010, and 2011 to 2020 were given. From 1992 to 2000, the threshold value of total phosphorus concentration was 0.135 mg·L-1 in spring, 0.174 mg·L-1 in summer, and 0.171 mg·L-1 in autumn. From 2001 to 2010, the threshold value of total phosphorus concentration was 0.115 mg·L-1 in spring, 0.164 mg·L-1 in summer, and 0.162 mg·L-1 in autumn. From 2011 to 2020, the threshold value of total phosphorus concentration was 0.059 mg·L-1 in spring, 0.145 mg·L-1 in summer, and 0.145 mg·L-1 in autumn. The results showed that the control of cyanoHABs in eutrophic lakes required more stringent nutrient control strategies with global warming. It provided a reference for preventing and controlling cyanoHABs and eutrophication in Lake Taihu. Previous studies have used multiple regression models, hydrodynamic numerical models, and other methods to predict chlorophyll-a concentrations or cyanobacterial blooms in lakes. However, there has been no study on the prediction of cyanoHABs in lakes based on the Bayesian network model with continuous variables and the "dynamic" evaluation of nutrient thresholds. Therefore, based on the seasonal meteorological, water quality, and biological monitoring data of Lake Taihu from 1992 to 2020, the chlorophyll-a model of Lake Taihu was constructed for the first time based on the Bayesian network model with continuous variables to simulate the chlorophyll-a concentration of Lake Taihu under different climate indicators and total phosphorus concentrations. The weight of its influencing factors was also analyzed, and the nutrient control objectives under different climate scenarios were "dynamically" evaluated.

[Community Structure of Phytoplankton and Environmental Impact Factors in Lake Hongze from 2015 to 2020].

Lake Hongze is an essential storage lake for the "Eastern Route of the South-North Water Diversion Project" and plays an important role in climate adjustment and flood prevention and control. To study the structural evolution of phytoplankton communities in Lake Hongze and their relationship with environmental factors and to understand the status of the ecosystem of Lake Hongze before the "ten-year fishing ban," monthly monitoring was carried out from 2015 to 2020. During the study period, total nitrogen showed a significant downward trend starting in 2017, the total phosphorus and chemical oxygen demand declined slightly, the water temperature had no obvious change trend, and the water depth and transparency increased from 2015 to 2018 and then declined significantly. A total of 102 genera of phytoplankton in eight phyla were identified, with a total of 310 species. The dominant phytoplankton phyla mainly included Chlorophyta and Bacillariophyta, followed by Cyanophyta and Pyrrophyta. The dominant genera were Scenedesmus, Aulacoseira, Cryptomonas, Cyclotella, Tetraedron, Microcystis, and Dolichospermum. The results of non-metric multidimensional scaling (NMDS) showed that the structural composition of the phytoplankton community differed significantly among years, seasons, and sampling areas, mainly due to the redistribution among dominant genera. NMDS analysis also indicated that variation in the phytoplankton community in Lake Hongze was mainly related to water temperature, total nitrogen, total phosphorus, water depth, and transparency. Total nitrogen, water depth, and phytoplankton community structure were significantly correlated with interannual succession, whereas water temperature, total nitrogen, and phytoplankton seasonal succession were also significantly correlated. Combined with the measures taken by the management department in recent years, the changes in the structure of the phytoplankton community may be related to the removal of the fence and other management and restoration measures in Lake Hongze.

Chemical pleurodesis and somatostatin in treating spontaneous chylothorax in pediatric patients: a retrospective analysis and review of the literature.

BACKGROUND: Chylothorax is a rare disease, defined as an abnormal accumulation of chylous lymphatic effusion in thoracic cavity, with a high mortality rate in pediatric patients. At present, there are few studies on the treatment of pediatric chylothorax, and conservative treatments like somatostatin (SST) and pleurodesis are performed empirically. SST has been used for treating pediatric chylothorax over 20 years, and povidone-iodine chemical pleurodesis (PICP) is adopted in recent years with a high cure rate, but both the effect are still uncertain. The safety and efficacy of SST and PICP in treating pediatric chylothorax was compared in this study. METHODS: From January 2009 to May 2020, 27 pediatric chylothorax patients who accepted life support, SST and PICP treatment were retrospectively reviewed in this study. Their medical history, clinical manifestations, pleural effusion examinations, treatment methods, effects, and complications were screened. PICP and SST was performed in 19 and 8 children, respectively. Each patient was followed up after discharge from the hospital. RESULTS: After admission, chest X-ray and ultrasound diagnosed pleural effusion in 27 patients (18 males and 9 females), including 13 and 6 cases on the left and right side, and 8 cases on both sides. In the pleural effusion, the mean leukocyte count was (9,826±9,482)×106/L, the mean lymphocyte ratio was (84.82±6.58)%, the mean triglyceride content was 7.11±6.63 mmol/L. In PICP and SST group, the mean length of stay was 38.42±19.42 and 35.13±12.72 d (P=0.664), the mean time of thoracic drainage was 24.58±16.34 and 19.63±8.88 d (P=0.440), the mean time of parenteral nutrition was 27.16±18.29 and 25.25±13.52 d (P=0.793), respectively. PICP was performed for 3.16±2.27 times, and SST was used for 14.75±9.08 d with the dosage of 0.5 to 10 µg/kg/hour. After the treatment, all patients in PICP group had mild chest pain and low-grade fever, and 12 cases were observed with transient decrease of oxygen saturation. Eight patients in SST group had nausea and vomit, and 1 child had diarrhea simultaneously. Both were cured by symptomatic treatment, thoracic drainage and discontinuing using SST. Three children were diagnosed with refractory chylothorax and cured by PICP after SST. Pleural effusion in 27 patients was finally absorbed. All of them achieved a clinical cure successfully, and there was no recurrence during discharge follow-up. CONCLUSIONS: PICP has a high success rate and few adverse reactions in treating spontaneous chylothorax in pediatric patients, expected to be a new treatment option for pediatric chylothorax after SST.

[Succession Pattern of Phytoplankton and Its Drivers in Lake Luoma, Jiangsu Province].

As a water storage lake for the South-to-North Water Diversion Project, it is crucial to examine changes in aquatic ecosystem structures in Lake Luoma, Jiangsu province. Field sampling was carried out in Lake Luoma monthly from 2014 to 2018 to study the relationship between the phytoplankton community structure and environmental factors. During the studied period, total nitrogen, permanganate index, and electrical conductivity in water column gradually increased, whereas fluoride content declined. The pattern of total phosphorus and dissolved oxygen was not distinct. A total of 71 genera of phytoplankton were identified from 2014 to 2018, and the average monthly biomass variation ranged from 0.16 to 5.51 mg·L-1. Bacillariophyta and Chlorophyta were the dominant phyla in the four years, followed by Pyrrophyta and Cryptophyta. The dominant genera were Synedra sp., Chroomonas spp., Aulacoseira spp., Dinobryon sp., Scenedesmus spp. , Fragilaria spp., Mougeotia sp. , Ankistrodesmus sp. , and Euglena spp. The results showed that the phytoplankton community structure significantly changed in the four years, which was mainly ascribed to the redistribution of biomass. Specifically, in addition to the dominance of Bacillariophyta and Chlorophyta, the dominance of Pyrrophyta and Cyanophyta increased during the last two years. Non-metric multidimensional scaling analysis showed that variation of the phytoplankton community in Lake Luoma was mainly related to total nitrogen, fluoride, water temperature, total phosphorus, dissolved oxygen, pH, conductivity, and permanganate index, among which the total nitrogen, water temperature, and fluoride concentration dominated the phytoplankton community change after the generalized additive model test. Water temperature is the driving factor affecting seasonal changes of the phytoplankton community. Total nitrogen and fluoride concentrations are the driving factors affecting the interannual variation in the phytoplankton community. Our study indicated that in recent years, the implementation of the ban on sand mining and demolition of the enclosed aquaculture in Lake Luoma has affected the water environment, resulting in a significant succession of the phytoplankton community.

Scaling the respiratory metabolism to phosphorus relationship in plant seedlings.

There are empirical indications of an isometric scaling relationship between plants' respiratory metabolism rates and nitrogen contents. To test the hypothesis that there may be a similar relationship between plants' respiratory metabolism and phosphorus contents we used data obtained from 150 laboratory and field-grown seedlings representing 30 herbaceous species and 20 woody deciduous species. Our results show that whole-plant respiration rates strongly scaled to the 0.81-power of the whole-plant phosphorus content, across wide ranges of growth conditions and functional classifications. Moreover, we also found a similar scaling exponent between whole-plant respiration rates and total nitrogen contents for the same set of samples. The similarities of the metabolic scaling relationships suggest that similar mechanisms may be involved in the transport and storage of phosphorus and nitrogen in plants.

The anticoagulant effect of PGI2S and tPA in transgenic umbilical vein endothelial cells is linked to up-regulation of PKA and PKC.

The selection of vascular grafts for coronary artery bypass surgery is crucial for a positive outcome. This study aimed to establish a novel line of vascular endothelial cells with a potent anticoagulant effect. A lentiviral vector was used to stably transfect human umbilical vein endothelial cells (HUVECs) with PGI2S alone (HUVEC-PGI2S) or both PGI2S and tPA (HUVEC-PGI2S-tPA). Both HUVEC-PGI2S and HUVEC-PGI2S-tPA cells over-expressing PGI2S and tPA were compared to mock-transfected cells. The enzyme-linked immuno sorbent assay (ELISAs) demonstrated that the anticoagulation components, ATIII and PLG, were up-regulated and coagulation factor FVIII was down-regulated in both cell lines. QRT-PCR and western blotting demonstrated the vasodilation and platelet disaggregation proteins PKA, PKC, and PTGIR were up-regulated in both cell lines, but MAPK expression was not altered in either cell line. However, cell viability and colony formation assays and cell cycle analysis demonstrated that both cell lines had a lower rate of cell growth and induced G1 phase arrest. HUVEC-PGI2S and HUVEC-PGI2S-tPA cells have a potent anticoagulant effect and their use in vascular heterografts may decrease the risk of thrombosis.

High expression of GOLPH3 in esophageal squamous cell carcinoma correlates with poor prognosis.

BACKGROUND: Whether the expression of Golgi phosphoprotein 3 (GOLPH3) correlates with esophageal cancer tumorigenesis is currently unclear. The aim of this study was to examine GOLPH3 expression in patients with esophageal squamous cell cancer (ESCC) and explore its clinical significance. METHODS: Differences in the expression of GOLPH3 at the mRNA and protein level were examined via quantitative reverse transcriptase PCR and western blotting, respectively. GOLPH3 expression levels in ESCC tissue were determined through immunohistochemistry, and were compared in accordance with specific clinicopathological features of the patients and tissue specimens. Factors associated with patient survival were also analyzed. RESULTS: A notably higher level of GOLPH3 expression was found in ESCC cell lines and tissues at both mRNA and protein levels. High expression of GOLPH3 in ESCC patients was positively associated with clinical stage, TNM classification, histological differentiation and vital status (all P<0.0001). Expression of GOLPH3 was found to be an independent prognostic factor in ESCC patients. ESCC patients expressing high levels of GOLPH3 exhibited a substantially lower 5-year overall survival than GOLPH3-negative patients. Furthermore, a significant correlation between high GOLPH3 expression and shorter overall survival time was found in different subgroups of ESCC patients stratified by the clinical stage, T classification, and lymph node metastasis. CONCLUSIONS: Experiments demonstrated potential involvement of GOLPH3 in the development, differentiation, and tumorigenesis of ESCC, and concludes the possibility of its use as a diagnostic and prognostic marker in patients with ESCC.

Mice harboring Gnrhr E90K, a mutation that causes protein misfolding and hypogonadotropic hypogonadism in humans, exhibit testis size reduction and ovulation failure.

GnRH, produced in the hypothalamus, acts on pituitary gonadotropes to stimulate release of the gonadotropins LH and FSH. Reduced responsiveness of gonadotropes to GnRH is a primary cause of hypogonadotropic hypogonadism (HH), a disease characterized by gonadal dysfunction and low blood levels of gonadotropins. Loss-of-function mutations in the gene encoding the receptor for GnRH (GNRHR) are a common cause of HH. Sequencing of the GNRHR gene in patients with HH revealed mainly point mutations producing single amino acid substitutions that cause misfolding and misrouting of this G protein-coupled receptor. To generate a mouse model that mimics the human disease, we introduced a single amino acid substitution (E90K) into the mouse Gnrhr gene, which is identical to a known human recessive mutation. In humans, E90K causes severe HH by preventing formation of the E90-K121 salt bridge, which is essential for correct folding. In cell cultures, E90K causes misfolding that leads to almost complete retention by the protein quality control system and subsequent degradation. Here we report that the primary phenotype of mice homozygous for E90K is female infertility due to ovulation failure. Mutant males are fertile despite reduced gonadotropin levels and smaller testes. These results suggest decreased GnRH receptor signaling in the mutant animal, compared with wild type. Our findings suggest that a threshold level of GnRH receptor activity is required for ovulation.

Trade-offs between the metabolic rate and population density of plants.

The energetic equivalence rule, which is based on a combination of metabolic theory and the self-thinning rule, is one of the fundamental laws of nature. However, there is a progressively increasing body of evidence that scaling relationships of metabolic rate vs. body mass and population density vs. body mass are variable and deviate from their respective theoretical values of 3/4 and -3/4 or -2/3. These findings questioned the previous hypotheses of energetic equivalence rule in plants. Here we examined the allometric relationships between photosynthetic mass (M(p)) or leaf mass (M(L)) vs. body mass (beta); population density vs. body mass (delta); and leaf mass vs. population density, for desert shrubs, trees, and herbaceous plants, respectively. As expected, the allometric relationships for both photosynthetic mass (i.e. metabolic rate) and population density varied with the environmental conditions. However, the ratio between the two exponents was -1 (i.e. beta/delta = -1) and followed the trade-off principle when local resources were limited. Our results demonstrate for the first time that the energetic equivalence rule of plants is based on trade-offs between the variable metabolic rate and population density rather than their constant allometric exponents.

An automated approach for direct measurement of two-dimensional strain distributions within articular cartilage under unconfined compression.

An automated approachfor measuring in situ two-dimensional strain fields was developed and validated for its application to cartilage mechanics. This approach combines video microscopy, optimized digital image correlation (DIC), thin-plate spline smoothing (TPSS) and generalized cross-validation (GCV) techniques to achieve the desired efficiency and accuracy. Results demonstrate that sub-pixel accuracies can be achieved for measuring tissue displacements with this methodology with a measurement uncertainty ranging from 0.25 to 0.30 pixels. The deformational gradients (from which the strains are determined) can be evaluated directly using the optimized DIC, with a measurement uncertainty of 0.017 to approximately 0.032. In actual measurements of strain in cartilage, TPSS and differentiation can be used to achieve a more accurate measurement of the gradients from the displacement data. Using this automated approach, the two-dimensional strain fields inside immature bovine carpometacarpal joint cartilage specimens under unconfined compression were characterized (n=21). The depth-dependent apparent elastic modulus and Poisson's ratio were also determined and found to be smallest at the articular surface and increasing with depth. The apparent Poisson's ratio is found to decrease with increasing compressive strain, with values as low as 0.01 observed near the articular surface at 25% compression. The variation of the apparent Poisson's ratio with depth is found to be consistent with a theoretical model of cartilage which accounts for the disparity in its tensile and compressive moduli.