Recent advance of ATP citrate lyase inhibitors for the treatment of cancer and related diseases.

ATP citrate lyase (ACLY), a strategic metabolic enzyme that catalyzes the glycolytic to lipidic metabolism, has gained increasing attention as an attractive therapeutic target for hyperlipidemia, cancers and other human diseases. Despite of continual research efforts, targeting ACLY has been very challenging. In this field, most reported ACLY inhibitors are "substrate-like" analogues, which occupied with the same active pockets. Besides, some ACLY inhibitors have been disclosed through biochemical screening or high throughput virtual screening. In this review, we briefly summarized the cancer-related functions and the recent advance of ACLY inhibitors with a particular focus on the SAR studies and their modes of action. We hope to provide a timely and updated overview of ACLY and the discovery of new ACLY inhibitors.

Polyacetylene Isomers Isolated from Bidens pilosa L. Suppress the Metastasis of Gastric Cancer Cells by Inhibiting Wnt/ß-Catenin and Hippo/YAP Signaling Pathways.

(E)-7-Phenyl-2-hepten-4,6-diyn-1-ol (1) and (Z)-7-Phenyl-2-hepten-4,6-diyn-1-ol (2) are isomeric natural polyacetylenes isolated from the Chinese medicinal plant Bidens pilosa L. This study first revealed the excellent anti-metastasis potential of these two polyacetylenes on human gastric cancer HGC-27 cells and the distinctive molecular mechanisms underlying their activities. Polyacetylenes 1 and 2 significantly inhibited the migration, invasion, and adhesion of HGC-27 cells at their non-toxic concentrations in a dose-dependent manner. The results of a further mechanism investigation showed that polyacetylene 1 inhibited the expressions of Vimentin, Snail, ß-catenin, GSK3ß, MST1, YAP, YAP/TAZ, and their phosphorylation, and upregulated the expression of E-cadherin and p-LATS1. In addition, the expressions of various downstream metastasis-related proteins, such as MMP2/7/9/14, c-Myc, ICAM-1, VCAM-1, MAPK, p-MAPK, Sox2, Cox2, and Cyr61, were also suppressed in a dose-dependent manner. These findings suggested that polyacetylene 1 exhibited its anti-metastasis activities on HGC-27 cells through the reversal of the EMT process and the suppression of the Wnt/ß-catenin and Hippo/YAP signaling pathways.

[Screening of the Optimum Medium for Rat Mesenchymal Stem Cells].

OBJECTIVE: To investigate the effect of three different cell culture mediums, DMEM-LG, α-MEM and DMEM/F12, on the growth of rat bone marrow mesenchymal stem cells (BMSCs) in vitro, and so that to screen out the most suitable medium for in vitro culturing the rat BMSCs. METHODS: BMSCS were isolated from the femur and tibia of SD rats by whole bone marrow differential adherence method. The isolated cells were then cultured with three culture mediums, DMEM-LG, α-MEM and DMEM/F12. The rat BMSCs morphology, adhesion, proliferation, the time of passage and the number the colony at day 14 in three mediums respectively were observed with inverted phase contrast microscopy and compared. Flow cytometry was used to identify and observe the effects of different mediums on the surface antigen expression of rats BMSCs. RESULTS: Compared with the other two groups of media, BMSCs cultured in DMEM-LG had shorter colony formation time, shorter first passage time, more clone formation (14±2) and showed uniform morphology and the highest attachment efficiency (47.0±2.8)%. Meanwhile, BMSCs cultured with DMEM-LG entered logarithmic growth phase after only 4 days of culturing and showed the highest average specific growth rate and the largest average number of propagations per unit time. The total number of cells reached about (2.2-2.7)×105 mL-1 within three days. The cells cultured with 3 mediums were all identified as rat BMSCs, and the expression of surface antigen in BMSCs was not significantly affected by different media. CONCLUSION: DMEM-LG is more suitable for proliferation of rat BMSCs in vitro.

Application of multiplex methylated-specific PCR with capillary electrophoresis to explore prognostic value of TSGs hypermethylation for hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is a malignant tumor that severely threatens human health. To date, early detection for HCC patients is particularly significant due to their poor survival rates even after liver resection. METHODS: Therefore, an efficient and sensitive detection method for monitoring liver cancer, multiplex methylation-specific PCR (MSP) coupled with capillary electrophoresis, is developed. RESULTS: Simulations demonstrated that the methylation status of RASSF1A, p16, SFRP1, and ELF could be detected even when DNA equaled or exceeded 12.5 ng simultaneously. Also, its accuracy for methylation detection outweighed polyacrylamide gel electrophoresis (87.5%) and agarose electrophoresis (84.3%), reaching 92.1%. Subsequently, we implemented multiplex MSP with capillary electrophoresis to investigate methylation status of the four tumor suppressor genes in tissue specimens and explore the prognostic value for HCC patients. As the data suggested, multivariate cox regression analysis revealed that the recurrence-free survival of 46 patients was greatly associated with portal vein tumor thrombus (PVTT) and p16 methylation and receiver operating characteristic (ROC) curves demonstrated that the predictive range of portal vein tumor thrombus (PVTT) combined with p16 hypermethylation was more sensitive than that of either PVTT or p16 hypermethylation alone with regard to disease recurrence in patients with HCC, which could be testified as a valuable biomarker in Clinical application. CONCLUSION: Multiplex MSP coupled with capillary electrophoresis has an excellent prospect of clinical application for monitoring early liver cancer and screening valuable biomarkers for prognosis of HCC patients.

[BORIS Regulates SOCS3 Expression Through Epigenetic Mechanisms in Human Hepatocellular Carcinoma Cells].

OBJECTIVE: To study the regulation of suppressor of cytokine signaling 3 (SOCS3) expression bythe brother of the regulator of the imprinted site (BORIS) in hepatocellular carcinoma cell. METHODS: The expression of SOCS3 mRNA in HCC cell lines was detected by real-time quantitative PCR (qRT-PCR). The expression of SOCS3 protein in knockdown and overexpression BORIS of HCC cell lines was tested by Western blot. The SOCS3 gene promoter methylation statusin the knockdown and overexpression BORIS of hepatocarcinoma cell lines was detected by using methylation specific PCR (MSP-PCR) method.The potential BORIS binding site of SOCS3promoter region was found by UCSC database analysis.The enrichment of BORIS in SOCS3 promoter region in endogenous high expression BORIS of HCC cells was evaluated by using chromatin immunoprecipitation (ChIP)-qPCR (ChIP-qPCR).The SOCS3 promoter region histone methylation status in the knockdown and overexpression BORIS of HCC was detected by ChIP-qPCR. RESULTS: The expression of SOCS3 mRNA in hepatocellular carcinoma cells was higher and SOCS3 protein expression was down-regulated or up-regulated in the knockdown or overexpression of BORIS mRNA hepatocarcinoma cells,so BORIS has a positive regulatory effect on SOCS3 protein expression in hepatocarcinoma cells. MSP-PCR experiments showed that the SOCS3 promoter in SMMC-7721 and HepG2 cells was unmethylated and knockdown of BORIS did not change the methylation status; the SOCS3 promoter region of Huh7 cells was methylated; after overexpression of BORIS,the SOCS3 promoter region was changed to an unmethylated state; the SOCS3 promoter was unmethylated in HCCLM3,overexpression of BORIS did not alter the methylation status. The ChIP-qPCR assay demonstrated that BORIS specifically binds to the SOCS3 promoter region in HCC cells with high expression of BORIS. Histone methylation assay indicated that knockdown of BORIS reduced BORIS enrichment in the SOCS3 promoter region, with decreasing H3K4 me2 and increasing H3K27 me3 in the region of histone,whereas the overexpress BORIS in HCC cells showed the opposite situation. CONCLUSION: BORIS plays a role of epigenetic regulationon SOCS3 gene promoter methylation and histone methylation,modulating the expression of SOCS3,and then involved in the development of hepatocellular carcinoma.

[Research on Chemical Constituents and Anti-tumor Activity of Eupatorium chinense].

Objective: To study the chemical constituents and their anti-tumor activity of Eupatorium chinense. Methods: The chemical constituents were separated and purified by the normal phase silica gel column chromatography,preparative thin-layer chromatography,and preparative HPLC. Their structures were determined by various spectral data,their antitumor activity in vitro was determined by MTT assay. Results: Six compounds were isolated from the ethyl acetate extract of Eupatorium chinense,and the structures were identified as eupalinilide G( 1),8ß-( 4'-hydroxytigloyloxy)-5-desoxy-8-desacyleuparotin( 2),3-( hydroxymethyl)-1,13,14,15-tetrahydroxy-7,11,15-trimethyl-2,6,10-hexadecatriene( 3),3-( hydroxymethyl)-1,13,15-trihydroxy-7,11,15-trimethyl-2,6,10-hexadecatrien-14-yl acetate( 4),eupafolin( 5) and hiyodorilactone B( 6). Compound 2 showed cytotoxicity against HGC-27 and B16 cancer cell lines with IC50 values of 4. 29 µg/m L and 5. 53 µg/m L,respectively. Methods: The chemical constituents were separated and purified by the normal phase silica gel column chromatography,preparative thin-layer chromatography,and preparative HPLC. Their structures were determined by various spectral data,their antitumor activity in vitro was determined by MTT assay. Results: Six compounds were isolated from the ethyl acetate extract of Eupatorium chinense,and the structures were identified as eupalinilide G( 1),8ß-( 4'-hydroxytigloyloxy)-5-desoxy-8-desacyleuparotin( 2),3-( hydroxymethyl)-1,13,14,15-tetrahydroxy-7,11,15-trimethyl-2,6,10-hexadecatriene( 3),3-( hydroxymethyl)-1,13,15-trihydroxy-7,11,15-trimethyl-2,6,10-hexadecatrien-14-yl acetate( 4),eupafolin( 5) and hiyodorilactone B( 6). Compound 2 showed cytotoxicity against HGC-27 and B16 cancer cell lines with IC50 values of 4. 29 µg/m L and 5. 53 µg/m L,respectively. Conclusion: Compounds 2 ~ 5 are isolated from the Eupatorium chinense for the first time,and compound 2 has significant cytotoxic activity against HGC-27 cell line.

Thermally Driven Pure Spin and Valley Currents via the Anomalous Nernst Effect in Monolayer Group-VI Dichalcogenides.

The spin and valley-dependent anomalous Nernst effects are analyzed for monolayer MoS_{2} and other group-VI dichalcogenides. We find that pure spin and valley currents can be generated perpendicular to the applied thermal gradient in the plane of these two-dimensional materials. This effect provides a versatile platform for applications of spin caloritronics. A spin current purity factor is introduced to quantify this effect. When time reversal symmetry is violated, e.g., two-dimensional materials on an insulating magnetic substrate, a dip-peak feature appears for the total Nernst coefficient. For the dip state it is found that carriers with only one spin and from one valley are driven by the temperature gradient.

[Segment Cloning and Expression of Human VIGILIN Gene].

OBJECTIVE: To investigate the mechanisms of interaction between high-density lipoprotein binding protein (HDLBP)-VIGILIN with other proteins, we cloned VIGILIN cDNA N, KH1-7, KH8-12, KH13-14, and C fragments separately into expression vector, and identify the expressed proteins. METHODS: The recombinant plasmid pDsred2-N1/VIGILIN was used as template to amplify VIGILIN full length, VIGILIN N terminal, KH1- 7, KH8-12, KH13-14, C terminal and recombinated them with pGEX 5X 3. After transformed into E. coli BL21 cells, the recombinants were confirmed by enzyme digestion and sequence analysis. After optimizing the IPTG inducing condition, we induced GST-VIGILIN fusion proteins on the appropriate conditions. RESULT: The recombinant plasmids of pGEX 5X 3/VIGILIN FL, pGEX 5X 3/VIGILIN N terminal, pGEX 5X 3/VIGILIN KH1-7, pGEX 5X 3/VIGILIN KH8-12, pGEX 5X 3/VIGILIN KH13-14, pGEX 5X 3/VIGILIN C terminal were constructed successfully, and induced the GST-VIGILIN fusion proteins. CONCLUSION: pGEX 5X 3/VIGILIN FL, pGEX 5X 3/VIGILIN N terminal, pGEX 5X 3/VIGILIN KH1-7, pGEX SX 3/VIGILIN KH8-12, pGEX 5X 3/ VIGILIN KH13-14, pGEX 5X 3/VIGILIN C terminal recombinant plasmids were constructed successfully, and their corresponding fusion proteins were successfully expressed.

[Cardioprotective Effect and Its Mechanism of Total Saponins of Panacis Majoris Rhizoma in Myocardial Infarction Rats].

OBJECTIVE: To explore the cardioprotective effect and its mechanism of total saponins of Panacis Majoris Rhizoma in myocardial infarction (MI) rats. METHODS: The MI model rats induced by ligating anterior descending branch of coronary artery were randomly divided into four group:model group, total saponins of Panacis Majoris Rhizoma (100 and 200 mg/kg) groups and compound Danshen dripping pills group. The rats were orally administrated with drugs once a day for four weeks. Another rats were selected as sham operation group. After four weeks intervention, cardiac function was examined, the serum levels of TNF-α, IL-1ß, IL-6 and IL-8 were measured by using ELISA, respectively. The myocardial hypertrophy index was investigated, the myocardial infarct size, degree of ventricular dilatation, myocardial interstitial collagen volume fraction and tissue morphology were investigated by HE, Masson, picric acid-sirius red staining and observing with alight microscope and electron microscope. Protein expressions of phosphorylation IκB-α( pIκB-α) and NF-κB p65 in heart tissue were detected by Western blotting. RESULTS: Total saponins of Panacis Majoris Rhizoma might significantly decrease the levels of serum TNF-α, IL-1ß, IL-6 and IL-8; decrease myocardial hypertrophy indexes, myocardial infarct size, degree of ventricular dilatation and myocardial interstitial collagen volume fraction; improve heart tissue morphology and cardiac function; downregulate protein expression of pIκB-α and NF-κBp65; and upregulate protein expression of SIRT1. The aforementioned action effects of total saponins of Panacis Majoris Rhizoma (200 mg/kg) were similar with compound Danshen dripping pills. CONCLUSION: Total saponins of Panacis Majoris Rhizoma possesses cardioprotective effect against ligating left anterior descending branch induced MI in rats. The mechanism may be related to strengthening SIRT1 expression, inhibiting the phosphorylation of IκB-α, and finally inhibiting the activation of NF-κB and proinflammatory production.

[Effects of CTCF on human liver cancer stem cells and cell proliferation].

OBJECTIVE: To explore the effects of CCCTC-binding factor (CTCF) on human liver cancer stem cells (HepG2) and cell proliferation of HepG2 and Nasopharyngeal carcinoma cell line (CNE1). METHODS: The pEGFP-N1/CTCF, CTCF-shRNA and GFP-shRNA plasmids were constructed and transfected into HepG2 and CNE1 cells, and RT-PCR or Western blot were performed to detect the mRNA or protein levels of CTCF. The subpopulation of CD90+ cancer stem cells in HepG2 cells transfected with CTCF-shRNA plasmid or GFP-shRNA plasmid (as transfection control) were assayed by flow cytometry with the wild type HepG2 cells as control. Proliferation of cells transfected with CTCF-overexpression or CTCF-shRNA plasmid was evaluated by MTT assay. RESULTS: The levels of both mRNA and protein of CTCF were increased in pEGFP-N1/CTCF transfected HepG2 and CNE1 cells compared to that in pEGFP-N1 transfected cells (P < 0.05), and decreased in CTCF-shRNA transfected cells compared to that in cells transfected with GFP-shRNA (P < 0.05). The results of flow cytometry demonstrated that, detection rate of CD90+ cells in cells transfected with CTCF-shRNA plasmid [(1.7330 +/- 0.4177)%] was obviously higher than that of wild-type HepG2 cells [(0.5750 +/- 0.0629)%] and cells transfected with GFP-shRNA plasmid [(0.3500 +/- 0.0866)%] (P < 0.05). The results of MTT analysis showed that, alteration of CTCF had no effect on cancer cell proliferation (P > 0.05). CONCLUSION: CTCF inhibits human liver cancer stem cells but no effect on cell proliferation.

Moyamoya syndrome may result from psoriasis: Four case reports.

BACKGROUND: Moyamoya syndrome (MMS) is a group of diseases that involves more than one underlying disease and is accompanied by moyamoya vascular phenomena. Psoriasis is a chronic immune skin disease closely linked to high blood pressure and heart disease. However, psoriasis-related MMS has not been reported. CASE SUMMARY: We collected data on patients with stroke due to MMS between January 2017 and December 2019 and identified four cases of psoriasis. Case histories, imaging, and hematological data were collected. The average age of the initial stroke onset was 58.25 ± 11.52 years; three cases of hemorrhagic and one case of ischemic stroke were included. The average duration from psoriasis confirmation to the initial MMS-mediated stroke onset was 17 ± 3.56 years. All MMS-related stenoses involved the bilateral cerebral arteries: Suzuki grade III in one case, grade IV in two cases, and grade V in one case. Abnormally elevated plasma interleukin-6 levels were observed in four patients. Two patients had abnormally elevated immunoglobulin E levels, and two had thrombocytosis. All four patients received medication instead of surgery. With an average follow-up time of 2 years, two causing transient ischemic attacks occurred in two patients, and no hemorrhagic events occurred. CONCLUSION: Psoriasis may be a potential risk factor for MMS. Patients with psoriasis should be screened for MMS when they present with neurological symptoms.

A novel snake venom C-type lectin-like protein modulates blood coagulation by targeting von Willebrand factor and coagulation factor IX.

Snake venom C-type lectin-like proteins (CLPs) belong to the nonenzymatic proteins. To date, no CLP with both platelet and coagulation factors activating activities has been reported. In this study, a novel CLP, termed protocetin, with molecular weight of 29.986 kDa, was purified from the Protobothrops mucrosquamatus venom (PMV). It consists of α- and ß-chains, with 67% similarity in their N-terminal sequence. Protocetin activates glycoprotein Ib (GPIb) by binding to von Willebrand factor (vWF), inducing platelet aggregation. It also activates the intrinsic coagulation pathway by binding to coagulation factor IX. After injection of protocetin into mice at dose of 0.5 µg/g or 1.5 µg/g, it resulted in activation of platelets, a notable reduction in platelet count and prolonged tail bleeding time. Additionally, the plasma activated partial thromboplastin time (APTT) was significantly extended, and the fibrinogen concentration was markedly reduced. Thrombelastogram comfirmed the anticoagulation effect of protocetin. Notably, no microthrombosis was observed in tissues of lung, liver and kidney within 1 h after injection of protocetin into the mice at dose of 0.5 µg/g. This study revealed protocetin as a novel CLP from PMV that has dual functions in activating platelet and coagulation factor IX, thereby modulates coagulation in vivo. This work contributes to a better understanding of the structure and function of snake venom CLP.

[Determination of eight cannabinoids in foods with enhanced matrix removal-lipid adsorbent by ultra performance liquid chromatography-tandem mass spectrometry].

A novel method was developed for the simultaneous determination of eight cannabinoids in six types of food matrices, including chocolate, fondant, biscuit, beverage, cookie and baijiu, using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The sample extraction and cleanup steps were optimized, and various purification methods were investigated to remove the oil matrix and glue in chocolate and fudge, respectively. Enhanced matrix removal-lipid adsorbent (EMR-Lipid) provided efficient, selective cleanup of the evaluated matrices. The sample was extracted using acetonitrile, followed by EMR-Lipid cleanup, and then dried using anhydrous sodium sulfate. The acetonitrile layer was concentrated by nitrogen to near-dry after 100 µL 10% glycerol in methanol was added to improve the recovery by reducing loss during concentration under the stream of nitrogen gas. Eight cannabinoids were separated using a Waters ACQUITY UPLC BEH Shield RP18 column (100 mm×3.0 mm, 1.7 µm). The responses of the cannabinoids in the positive and negative ionization modes were investigated and optimized, and the responses were superior in the negative ion mode compared to those in the positive ion mode. MS detection was performed in the multi-reaction monitoring (MRM) mode using an electrospray source in the negative ion mode. The cannabinoids were quantified using an external standard with matrix calibration curves to reduce the influences of the matrix effects on the quantitative results. The developed method was verified, and the conditions of sample pretreatment were also optimized. The calibration curves of tetrahydrocannabinol, cannabidivarin, tetrahydrocannabivarin, and cannabigerol and those of cannabidiol, cannabinol, cannabidiolic acid, and tetrahydrocannabinolic acid exhibited good linearities, with r>0.995, in the ranges of 2-200 and 0.4-40 ng/mL, respectively. The respective limits of detection (LODs, S/N=3) and quantification (LOQs, S/N=10) of tetrahydrocannabinol, cannabidivarin, tetrahydrocannabivarin, and cannabigerol were 4 and 10 µg/kg, and those of cannabidiol, cannabinol, cannabidiolic acid, and tetrahydrocannabinolic acid were 0.8 and 2 µg/kg. The average recoveries of the cannabinoids were 82.0%-114.9% under three spiked levels with corresponding relative standard deviations (RSDs) of <15% (n=6). EMR-Lipid provided efficient, selective cleanups of food matrices with good accuracy. The method is sensitive, rapid, accurate, simple to execute, and it is suitable for the determination of cannabinol compounds in typical food matrices.

[Source and Optical Dynamics of Chromophoric Dissolved Organic Matter in the Watershed of Lake Qinghai].

Lake Qinghai is the largest lake in China and is of great significance to maintain the ecological security of the Qinghai-Tibet Plateau. Few studies have been carried out to investigate the optical composition and source of chromophoric dissolved organic matter (CDOM) in large lakes on the Qinghai-Tibet Plateau. It is of great significance to study the source and optical dynamics of CDOM in Lake Qinghai watershed for water quality protection and filling in the gaps in the knowledge of CDOM variability in a remote area. Two sampling campaigns in the Lake Qinghai watershed were carried out, and excitation-emission matrices coupled with parallel factor analysis (EEMs-PARAFAC) were used to unravel the optical composition and the sources of CDOM. Our results indicated that the mean dissolved organic carbon (DOC) concentration, a250:a365, and the spectral slope of CDOM absorption S275-295 in the lake were significantly higher than that in the inflow river (P<0.0001, t-test), whereas the mean absorption coefficient of CDOM a350, humification index (HIX), fluorescence peak integration ratio IC:IT, and specific ultraviolet absorbance at 254 nm SUVA254 of CDOM were shown to be lower in the lake than in the inflow river (P<0.0001), indicating that compared with the lake itself, CDOM in the inflow was humic-rich and highly aromatic. Four fluorescent components were obtained using PARAFAC, including a terrestrial human-like component C1, a microbial human-like component C2, a tyrosine-like C3, and a tryptophan-like C4. The mean DOC concentration, S275-295, and a250:a365in the headwater streams of the Lake Qinghai watershed were lower than those in the downstream estuary, indicating that the CDOM abundance increased, and the molecular weight decreased, from the headwaters to the downstream river mouths. The mean of SUVA254, C1, and the first axis of principal component analysis were positively related to terrestrial input (i.e., the PC1 values were significantly higher in rivers than in lakes (P<0.001)), indicating that the aromaticity of CDOM in rivers was higher than that in lakes. Particularly, the contribution of terrestrial humic-like C1 was higher in the Quanji River, Shaliu River, and Khargai River compared with that in other tributaries due to an intensified cultivated land use at the downstream estuary of these rivers.

[Emission of Nitrous Oxide (N2O) from Lake Taihu and the Corresponding Potential Driving Factors].

Nitrous oxide (N2O) is one of the six greenhouse gases stipulated in the Kyoto Protocol. Its greenhouse potential over the past century was 298 times that of CO2, and the concentration of atmospheric N2O has been continuously and rapidly increasing during the past hundred years. Shallow lakes are an important source of atmospheric N2O. In order to explore the temporal and spatial changes and potential driving factors of N2O emissions from eutrophic water, we conducted field observations in February (winter) and August (summer) in Lake Taihu. We used the coefficient of diffusion-headspace bottle method to trace the variability in the N2O concentration[c(N2O)] and efflux[F(N2O)] from surface water bodies and explored the potential driving factors of N2O emissions. The optical measurements of dissolved organic matter (DOM) are an effective approach for tracing the source and composition of dissolved organic carbon (DOC) and dissolved organic nitrogen (DON). The migration and transformation processes of DOM also release a large amount of inorganic nitrogen, which changes the redox potential of the water column and thereby affects N2O emissions. Our results showed that the variability in c(N2O) and F(N2O) in the surface waters of Lake Taihu were strongly affected by water temperature and nutrient levels. The average c(N2O) of the surface waters was (19.7±2.7) nmol·L-1, corresponding to a mean F(N2O) of (41.1±1.8) µmol·(m2·d)-1, and the means of both c(N2O) and F(N2O) were higher in summer than those in winter (t-test, P<0.01). The input and accumulation of DOM could increase the production and emission potential of N2O in water bodies, as supported by both c(N2O) and F(N2O) significantly increasing with increasing level of terrestrial humic-like C1. The integration ratio of peak C to peak T IC:IT of DOM and the spectral slope S275-295 results indicated that there were high inputs of terrestrial DOM in the northwestern inflowing river mouths, concurring with the high production and emission of N2O found there. This suggested that the accumulation and degradation of terrestrial DOM potentially fueled the emission of N2O. Our results showed that water temperature, DOM composition, and nutrient level were all important factors affecting N2O emission from Lake Taihu. Long-term continuous observation can be applied to better evaluate the impact of various environmental factors on the production and emission of N2O in water bodies and to help with providing scientific emission reduction plans.

[Optical Composition and Potential Driving Factors of Chromophoric Dissolved Organic Matter in Large Lakes and Reservoirs in the Eastern Region of China].

Intensified urbanization has been occurring in the eastern region of China in recent decades, and excessive industrial and household sewage has been discharged into lakes and reservoirs, which has directly lowered water quality and destructed the functions of aquatic ecosystems. Lakes and reservoirs are typically drinking water sources supplying water for metropolitan areas as well as large- and medium-sized cities. Chromophoric dissolved organic matter (CDOM) is the colored fraction of DOM, and its source and optical composition strongly affect water supply safety and the health of surrounding citizens. In April 2021, we collected 68 samples from Reservoir Changtan (n=11), Lake Taihu (n=25), Lake Hongze (n=18), and Lake Gaoyou (n=14), and we further carried out 28 days of laboratory bio-incubation, together with optical measurements and parallel factor analysis (EEMs-PARAFAC) to analyze the bio-degradability ω(BDOC), sources, and optical composition of CDOM in these waters. The results showed that after 28 days of laboratory bio-incubation, the bioavailability of dissolved organic carbon (BDOC) of the four lakes and reservoirs were all higher than 50%. PARAFAC results showed that CDOM collected from the four lakes was composed of four fluorescent components, including a terrestrial humic-like C1, a tryptophan-like C2, and tyrosine-like C3 and C4. Protein-like components (C2, C3, and C4) contributed importantly to the CDOM pool in the four waterbodies, and in Lake Hongze the contribution of C2-C4 was as high as (90.0±2.2)%. In Lake Hongze, total phosphorus (TP) correlated closely with C1-C3, indicating that those components can be used to trace the variability of TP. Among the four waterbodies, a254 was positively correlated with DOC (R2=0.96, P<0.01), indicating that a254 can be used to estimate the dynamics of DOC in these waters. In Lake Taihu, we found a low level of humification index (HIX) and a high level of biological index (BIX), indicating that autochthonous substances contributed importantly to the CDOM pool in this lake. In comparison, allochthonous sources contributed importantly to the CDOM pool in the remaining three waters. The enhanced monitoring of the discharge of industrial and agricultural effluents in the upstream watersheds of the four waters can help to protect the water quality and maintain healthy aquatic ecosystems.

[Emission of Methane from a Key Lake in the Eastern Route of the South-to-North Water Transfer Project and the Corresponding Driving Factors].

Lakes play an important role in the biogeochemical cycling of dissolved organic matter (DOM) and the emission of methane (CH4). We investigated the concentration and effluxes of CH4 and then analyzed the corresponding driving factors in Lake Luoma, a key lake along the South-to-North Water Transfer Project. Our results indicated that Lake Luoma was a hotspot of CH4 emissions with an annual mean concentration and efflux of (0.12±0.09) µmol·L-1 and (21.0±18.5) mmol·(m2·d)-1, respectively. We found higher mean CH4 levels in the wet season than those in the dry season and further higher levels than those in the wet-to-dry transition season. Spatially, the CH4 efflux was higher in the northwest inflowing regions and lower in the southeast outflow regions. The variability in annual CH4 efflux was affected by a combination of water temperature and hydrological conditions. Terrestrial input of dissolved organic carbon (DOC) and chromophoric DOM (CDOM) had fueled the production of CH4 by providing necessary carbon substrates, and four PARAFAC DOM components were identified including a microbial humic-like C1, a tryptophan-like C2, a terrestrial humic-like C3, and a tyrosine-like C4. The CH4 efflux from the lake was significantly promoted by the input and accumulation of terrestrial humic-like components, and Chl-a had no correlation with CH4 efflux, suggesting that algal degradation was not directly fueling the emission of CH4. Lake Luoma had been significantly disturbed by human activities, and terrestrial input of nutrient loading (TN and TP) into the lake not only improved the productivity and trophic level of the water body but also enhanced the production and release of CH4 from the surface water. We concluded that the CH4 emissions in Lake Luoma can be influenced by the combination of environmental factors, CDOM composition, and nutrient level. Long-term observation is needed for better evaluation of the driving factors in fueling the emission of CH4 so as to effectively reduce the emissions of CH4 and other greenhouse gases by taking corresponding countermeasures.

[Influences of Hydrological Scenarios on the Bioavailability, Fate, and Balance of Chromophoric Dissolved Organic Matter in Lake Poyang].

Lake Poyang has significant differences in hydrological characteristics between the flood and dry seasons. Unraveling the optical composition, bioavailability, fate, and balance of chromophoric dissolved organic matter (CDOM) and organic carbon fluxes in Lake Poyang under different hydrological conditions can help provide advanced schemes on carbon cycling, the transfer and transformation of organic matter, and water resource management of the lake. Three fluorescent components, including a humic-like (C1), a tryptophan-like (C2), and a tyrosine-like (C3) component, were obtained using three-dimensional fluorescence spectroscopy coupled with parallel factor analysis. Prior to and after 28 days of laboratory biodegradation, the means of a254 and the terrestrial humic-like (C1) component in the flood season were both significantly higher than that in the dry season (t-test, P<0.01), indicating that the terrestrial humic-like (C1) component contributed importantly to the CDOM pool. The contribution percentages of protein-like components in the dry season were 81.7% of the summed fluorescent components of CDOM, indicating that there might be discharge of domestic wastewater from areas surrounding the lake in the dry season. The bioavailabilities of the humic-like (C1) component and DOC were 14.0% and 43.2%, respectively, in the dry season. This can be explained by a declined-dilution effect in the lake during the dry rather than in the flood season. We observed no significant difference in the bioavailability of protein-like components under different hydrological conditions. The bioavailability of C1 (i.e.,%ΔC1) showed a decreasing trend from the southern inflowing river mouths to the downstream northern outlet at Hukou in both the flood and dry seasons, indicating that the bioavailability of the C1 decreased following the migration of CDOM in the lake. In the dry season and flood season, Lake Poyang was the source of DOC with fluxes of 14.0×103 t·mon-1 and 1.4×103 t·mon-1, respectively, whereas CDOM fluxes in corresponding periods were the source and weak sink with corresponding fluxes of 9.3×1010 m3·(m·mon)-1 and 1.1×1010 m3·(m·mon)-1, respectively. Therefore, the lake released substantial organic matter to the downstream receiving waters during the dry season, whereas in the flood season, the higher water level in the Yangtze River resulted in a prolonged water residence time of the lake, and a fraction of CDOM was bio-degraded into inorganic nutrients, favoring the metabolisms and the eutrophication process of the lake ecosystem.

[Value of BI-RADS ultrasonic scores of direct and indirect ultrasonographic signs in diagnosis of solid breast lesions].

OBJECTIVE: To explore the value of BI-RADS ultrasonic scores of direct and indirect ultrasonographic signs in diagnosis of solid breast lesions. METHODS: Reference to the standard BI-RADS score, ultrasonic scores of direct and indirect ultrasonographic signs of 132 solid breast lesions were assigned, and were compared with pathological results. RESULTS: By the direct signs of breast lesions (aspect ratio, shape, border, internal echo, posterior echo, flow grade, sand-like calcification) and indirect signs (changes in local skin thickness, Cooper ligament changes, axillary lymph nodes, depth of reinforcement membrane changes, mass changes in the surrounding burr), the integral from the total scores in benign and malignant breast masses showed a statistically significant difference. The total score of malignant lesions (8.94 ± 2.85) was significantly higher than that of benign tumors (3.09 ± 1.97, P < 0.05). Except skin thickness, all the remaining scores of the signs of benign and malignant breast tumors showed a significant difference between the two groups (P < 0.05). By receiver operating curve (ROC) analysis, the best critical value of the total score of direct signs was ≥ 4, with a sensitivity and specificity of 0.84 and 0.93, respectively, in distinguishing breast carcinoma from benign lesions. The best critical value of the total score of indirect signs was ≥ 1, with a sensitivity and specificity of 0.82 and 0.74, respectively. The critical value of the combination of the direct and indirect signs was ≥ 5 in differential diagnosis of malignant and benign lesions, with a sensitivity and specificity value of 0.88 and 0.90, respectively. CONCLUSION: The assignment score to the ultrasound characteristics of the direct and indirect signs of solid breast lesions can make a more objective diagnosis, yet it is a simple, effective, comprehensive and semi-quantitative analysis method.