[Spatial and temporal variations of landscape ecological risk in the dry and hot valley of the Jinsha River during 2000-2020]. / 2000­2020年金沙江干热河谷景观生态风险的时空变化.

Scientific assessment of landscape ecological risk in ecologically fragile areas of the upper reaches of the Yangtze River is of great significance to regional ecological regulation and construction of the Yangtze River ecological security barrier. With the dry-hot valley area of Jinsha River in Yunnan Province as the research area, we constructed a landscape ecological risk evaluation model, and analyzed the spatial and temporal variations of regional landscape ecological risk. The results showed that the average values of landscape ecological risk index (LER) in the study area were 0.414, 0.398, and 0.462 in 2000, 2010 and 2020, respectively. The LER value of the whole region had reached a higher risk level by 2020. In 2000 and 2010, the landscape ecological risk zones of each level were staggered, and the high-risk zones showed a centralized distribution in 2020. During the two decades, the average LER of each section in the study area was around 0.42, which was close to the high risk level, indicating high landscape ecological risk level. The area of middle and low risk zones had decreased, while the area of high risk zone had significantly increased. The area of high risk zone in the western and middle sections was much higher than that in the eastern section. The area with significant changes of landscape ecological risk accounted for about 55% of the total study area, with obvious spatial agglomeration characteristics of significant increase and decrease of risk. The competition between government-led ecological management policies and measures and market-led land use activities was the main cause of landscape ecological risk variations in this region. In the future, the driving mechanism of climate change coupled with human activities on global and local landscape ecological risk changes in the study area should be uncovered to effectively cope with regional ecological risks.

The impacts of flowering phenology on the reproductive success of the narrow endemic Nouelia insignis Franch. (Asteraceae).

Nouelia insignis Franch. (Asteraceae) is a short, narrow endemic and endangered tree, growing with a natural population in the dry and hot valley of the Jinsha River in the southwest area of China. In this work, flowering phenology (time and duration), floral biology, visit frequency and behavior of pollinators, and pollination characteristics were studied based on investigation in the field and analysis in the laboratory with the help of a stereomicroscope, and the relationship between seed setting rate and reproductive traits, as well as the relationship between flowering time and rainfall before flowering, was tested using the method of general linear regression model. The results showed that natural population of N. insignis exhibited high flowering synchrony with relatively stable flowering duration, and the flowering time fluctuated greatly depending on the rainfall 5 months before flowering. The pollination of N. insignis required pollinators, and insect activities played a very important role in the pollination process. However, lack of the pollinators was not a limitation for reproductive fitness in N. insignis, although the number of pollinators was small and the frequency of visits was low. In addition, no pollen limitation was found during pollination. The average seed setting rate of N. insignis in the natural condition was only 1.52%-3.73%, and it was generally affected by changes in flowering phenology between years and had a higher seed set in early flowering year. The annual variation of seed set might be related to the annual variations of stamen and pistil functions, such as changes of pollen viability and stigma receptivity, which were closely related to flowering time. The results of this study are of value for further conservation actions on natural population of this threatened endemic plant.

EAG responses of Apis cerana to floral compounds of a biodiesel plant, Jatropha curcas (Euphorbiaceae).

The Eastern honey bee, [Apis cerana (F.)], is an important and common pollinator for an important biodiesel tree, [Jatropha curcas (L.)]. To understand sensitivity of A. cerana to different floral compounds, we quantified volatile floral compounds of J. curcas, then determined electroantennogram (EAG) responses of A. cerana to 11 compounds each at five doses (0.4, 4, 40, 400, and 4,000 microg) of six most active floral compounds. Our results demonstrated that floral compounds of J. curcas differ in variety and quantity while linalool is always a major constituent in floral blends from three different plantations. Antennae of A. cerana responded to all 11 floral compounds, implying a broad sensitivity of A. cerana to different floral compounds of J. curcas. Antennae of A. cerana were most sensitive to six compounds, including all aldehydes (decanal, hexanal, nonanal, and octanal), linalool, and an alcohol (3-hexenol), suggesting that A. cerana possesses chemoreceptors to aldehydes, linalool, and alcohol on the antenna. Furthermore, low doses elicited a zero EAG response and high doses a positive one under all of six most active compounds. Thus, EAG responses of A. cerana were both chemical specific and dose-dependent. Our results here suggest that A. cerana is senstive to various floral compounds, and linalool in the floral blends of J. curcas plays a key role to attract A. cerana.

3,4-ethylenedioxythiophene as an electron donor to construct arylamine sensitizers for highly efficient iodine-free dye-sensitized solar cells.

The development of arylamine photosensitizers with high extinction coefficients, and suitable electronic structures and steric properties is necessary for improving the efficiency of dye-sensitized solar cells (DSCs) employing iodine-free redox shuttles. A new truxene-based organic sensitizer, M20, incorporating a 3,4-ethylenedioxythiophene (EDOT) moiety as an electron donor was synthesized and compared to its reference sensitizer, M4. M20 sensitized DSCs employing the Co(II/III) tris(1,10-phenanthroline)-based redox electrolyte exhibit a short circuit photocurrent of 11.8 mA cm(-2), an open circuit voltage of 903 mV, and a fill factor of 0.69, corresponding to an overall conversion efficiency of 7.35% under standard AM 1.5 sunlight, which is higher than that of 6.86% for equivalent M4 sensitized DSCs. The effects of 4-tert-butylpyridine (TBP) as an additive on the photovoltaic performance of truxene-dye-sensitized nanocrystallineTiO2 solar cells were also investigated.

[Relationship between changes of herbaceous plants and Oncomelania hupensis snail distribution under walnut forest of inhibition of snails in mountainous regions of Yunnan Province].

OBJECTIVE: To explore the relationship between the changes of herbaceous plants and Oncomelania hupensis snail distribution under the walnut forest of inhibition of snails in mountainous regions of Yunnan Province. METHODS: The experimental field was established at Sanying Village of Eryuan County, Yunnan Province, where the "Flourishing Forest and Controlling Snails Project" was implemented. The different stand ages (2, 4, 6, 8, 10 years)of walnut forest in experimental groups were selected based on the method of space replacing time, and the non-stocked land was served as a control group. The growth of forest, change of snails, number, biomass, overcast, height of the herbaceous plant and the soil moisture were investigated. RESULTS: The crown closure of 6-year-old walnut forest of inhibition of snails was 0.65. There were 11 species of herbaceous plant belonging to 11 genera, 6 families in 10-year-old forest and its crown closure was 0.77. Compared with the control group, the numbers of families, genera, and species of the 10-year-old forest were decreased by 64.71%, 69.44%, and 77.08%, and the biomass, overcast, and height of it decreased by 12.63%, 19%, and 22.18%, respectively. The soil moisture content (0-20 cm) monthly changes were increased obviously with the increase of stand age. There were no snails besides the control group and 2-year-old walnut forest. Compare with the control group, the occurrence rate of frames with living snails in the 2-year-old walnut forest was decreased by 50%, which was 1.25%. The density of living snails was decreased by 60.16%. CONCLUSIONS: The construction of walnut forest of inhibition of snails in mountainous regions of Yunnan Province are suitable for controlling the growth of herbaceous plants and altering the environment of snails. If the coalescence intercropped with crops is carried out, it is not only beneficial to the construction of good ecological environment, but also improves the utilization efficiencies of land, light, and thermal resource, and the income of peasants.

[Characteristics of carbon sequestration and apparent stability of new sequestered carbon in forested torrid red soil at dry-hot valley].

Great concerns about potential for carbon (C) sequestration in forested soil and the stability of the sequestered C have been exerted under the background of global climate change. Organic C density in soil and in soil physical and biochemical fractions at various stages (1991, 1997, 2003 and 2010) in Acacia auriculiformis stand afforested in 1991 were investigated at Dry-Hot Valley via density fractionation and acid hydrolysis. The results showed that organic C density at surface (0-15 cm) and subsurface (15-30 cm) soil layers was 1.40 kg x m(-2) and 0.99 kg x m(-2) after 19 years of afforestation, respectively. The annual C sequestration rates of surface and subsurface soil layers were 37.89 g x (m2 x a)(-1) and 16.84 g x (m2 x a)(-1) during 1991-2010, respectively, and the sequestration was accelerating. The ratio of organic C in heavy fraction to in surface soil was 71.44% in 2003, which was significantly higher than that in 2010 (67.99%). The recalcitrant carbon index (I(RC)) in light fraction was significantly higher than that in heavy fraction at surface or subsurface layers in 2003, but both decreased with aging of plantation, especially I(RC) in light fraction. Approximately 57% - 70% of new sequestered C was protected by physical mechanism and 33-49 percent was biochemical recalcitrant C during the stage from 12 to 19 years after afforestation. The results reveal that forested torrid red soil at Dry-Hot Valley may have a considerable capability of C sequestration. The biochemical stability of physically protected C is lower than the unprotected. Both the stability, however, decreases with the plantation age.

[Soil labile organic carbon contents and their allocation characteristics under different land uses at dry-hot valley].

Soil organic carbon (SOC), readily oxidation organic carbon (ROC), microbial biomass carbon (MBC)and dissolved organic carbon (DOC) contents and their allocation ratios were comparatively investigated under Leucaena leucocephala woodland, Acacia auriculiformis woodland, dry cropland and wasteland in dry-hot valley. Results showed that SOC contents were not significant differences among the four land uses with the range of 4.22-5.19 g x kg(-1). ROC contents under L. leucocephala (2.14 g x kg(-1)) and A. auriculiformis woodland (2.03 g x kg(-1)) were both significantly higher than those under dry cropland (1.38 g x kg(-1)) and wasteland (1.34 g x kg(-1)). The highest MBC and DOC contents both presented under dry cropland among the four land uses, whereas the lowest occurred under wasteland. ROC allocation ratios under woodlands were 1.3 to 1.6 times to those under dry cropland and wasteland. MBC and DOC allocation ratios under cropland were higher than those under other three land uses, and the ratios were closely among woodlands and wasteland. Plant residue amounts and management were primarily determined ROC contents, and soil water content and plant residue quantity were mainly affected the variation of MBC and DOC contents under the four land uses. The change of ROC contents could sensitively indicate SOC dynamics in dry-hot valley, but the change of MBC or DOC could not.

Effects of placental isoferritin on the mouse embryo development in vitro.

To investigate the effect of placental isoferritin (PLF) on mouse embryo development in vitro, mice 2-cell embryos were co-cultured with human first trimester decidual cells at different concentrations of PLF in vitro. The following changes of the above system were observed under an invert microscope and the number of embryos were recorded and the embryos were classified. The results showed there was no significant difference in the percentage of embryos development to 4-cell, 8-cell and morula (P>0.05). PLF at the doses of 10 and 100 U/mL significantly enhanced more embryos development to the blastocyst and hatching blastocyst (P<0.05). PLF at the dose of 1000 U/mL depressed more embryos development from 2-cell to hatching blastocyst, meanwhile such phenomena as cell degeneration and irregular cleavage were observed in part of embryos, but there was no significant difference in statistics (P>0.05). It was concluded that PLF at the concentration of 10-100 U/mL had no significant effects on the early development of mice embryos, however, PLF could promote the growth, differentiation, and hatching of preimplantation blastocysts.

[Detection and significance of phosphatidylinositol 3-kinase in adipose tissue of polycystic ovary syndrome patients with insulin resistance].

OBJECTIVE: To investigate the expression of phosphatidylinositol 3-kinase (PI-3K) in adipose tissue of polycystic ovary syndrome patients (PCOS), and explore molecular mechanisms of insulin resistance (IR) in PCOS. METHODS: Samples from patients with PCOS with IR (n = 19), PCOS without IR (n = 10) and controls (n = 15) were collected. Serum fasting insulin (FIN) and fasting plasma glucose (FPG) were measured. Insulin resistance index was calculated using homeostasis model assessment (HOMA) to analyze the relationship between these markers and IR. Western blot technique was used to detect the PI-3K p85 subunit. Gene expression of PI-3K p85 subunit was detected by reverse transcription polymerase chain reaction (RT-PCR) method. Kinase activity was detected by immunoprecipitation, thin-layer chromatography and gamma scintillation counting. RESULTS: (1) The levels of FIN [(25.2 +/- 3.8) mU/L] and HOMA-IR (1.6 +/- 0.3) in PCOS with IR were significantly higher than those in PCOS without IR [(13.4 +/- 3.8) mU/L, 0.9 +/- 0.3] and controls [(9.5 +/- 2.6) mU/L, 0.5 +/- 0.3; all P < 0.05). (2) There was no significant difference in the protein (0.65 +/- 0.10) and gene expression (0.92 +/- 0.12) of PI-3K p85 subunit in PCOS with IR compared with PCOS without IR (0.72 +/- 0.10, 1.01 +/- 0.10) and control groups (0.73 +/- 0.14, 1.00 +/- 0.12; P > 0.05). (3) PI-3K activity in PCOS with IR (81%) and PCOS without IR (89%) was significantly decreased (P < 0.01, P < 0.05) and negatively correlated with HOMA-IR (r = -0.69, P < 0.01; r = -0.62, P < 0.05). CONCLUSIONS: No significant difference in the protein and gene expression of PI-3K p85 subunit in PCOS with IR is found. The decreased PI-3K activity may lead to IR of PCOS.

Effects of metformin combined with cyproterone acetate on clinical features, endocrine and metabolism of non-obese women with polycystic ovarian syndrome.

In order to explore the effects of metformin combined with cyproterone acetate (CPA) on the clinical features, endocrine and metabolism of the patients with polycystic ovarian syndrome (PCOS), 50 cases of non-obese PCOS were randomly subjected to CPA (CPA treatment group, n = 25) and CPA+ metformin (n = 25) treatment for 6 months. Before and after treatment the body mass index (BMI), waist : hip ratio (WHR), ovarian volume, serum gonadotrophin, androgen and sex hormone-binding globulin (SHBG) levels, and fasting lipid, glucose and insulin levels were measured. The results showed that all of the parameters in two groups were similar before treatment. After treatment for 6 months in the CPA+ metformin group, BMI and WHR were significantly decreased, while insulin sensitivity was significantly decreased as Compared with those before treatment. In CPA group, no significant changes were found before and after treatment. Combined use of CPA and metformin could result in the reduction of serum androstenedione and increases of serum SHBG levels as compared with the CPA treatment alone. It was concluded that combined use of CPA and metformin could improve the insulin sensitivity, and further suppress the hyperandrogenism in non-obese women with PCOS.

[Tyrosine phosphorylation and protein expression of insulin receptor substrate-2 in the adipose tissue from patients with polycystic ovary syndrome].

OBJECTIVE: To explore molecular mechanisms of insulin resistance of polycystic ovary syndrome (PCOS) by determining the tyrosine phosphorylation and protein expression of insulin receptor substrate-2 (IRS-2) in adipose tissue from patients with PCOS. METHODS: Serum and subcutaneous adipose tissue samples from patients with PCOS with insulin resistance (n = 19), PCOS without insulin resistance (n = 17) and controls (n = 20) were collected. The expression of IRS-2 in adipose tissue was assessed by Western blot. Immunohistochemistry was used to detect the distribution of IRS-2 in adipose tissues of all patients. The tyrosine phosphorylation of IRS-2 was measured by immunoprecipitation and enhanced chemiluminescent immunoblotting technique. RESULTS: (1) There was no significant difference of the protein expression of IRS-2 in PCOS with insulin resistance 1.15 +/- 0.26 compared to those in PCOS without insulin resistance 1.13 +/- 0.26 and control group 1.00 +/- 0.25 (P > 0.05); (2) The tyrosine phosphorylation of IRS-2 was significantly decreased in PCOS with insulin resistance 0.77 +/- 0.16 compared to that of PCOS without insulin resistance 0.91 +/- 0.25 and control groups 1.00 +/- 0.12 (P < 0.05). There was no significant difference between PCOS without insulin resistance and control groups (P > 0.05). CONCLUSIONS: The decrease of tyrosine phosphorylation of IRS-2 in PCOS patients, which induces impairment of the insulin signal pathway, may be one of the mechanisms leading to insulin resistance.

[Tyrosine phosphorylation and protein expression of insulin receptor substrate-1 in the patients with polycystic ovary syndrome].

OBJECTIVE: To investigate the tyrosine phosphorylation and protein expression of insulin receptor substrate-1 in adipose tissue from patients with polycystic ovary syndrome, and explore molecular mechanisms of insulin resistance of PCOS. METHODS: Samples from patients with PCOS with insulin resistance (group A, n = 19), PCOS without insulin resistance (group B, n = 10) and controls group (n = 15) were collected. Serum luteinizing hormone (LH), follicle stimulating hormone (FSH) and testosterone (T) were measured by chemiluminescence assay. Fasting insulin (FIN) was measured by radioimmunoassay. Fasting plasma glucose (FPG) was measured by oxidase assay. Insulin resistance index was calculated using homeostasis model assessment (HOMA) to analyze the relationship between these markers and insulin resistance. The amount of insulin receptor substrate-1 in adipose tissue was assessed by western blot. The tyrosine phosphorylation of IRS-1 was measured by immunoprecipitation. RESULTS: (1) The levels of serum LH (15.8 +/- 2.8) U/L, LH/FSH 2.8 +/- 0.6, T (4.3 +/- 0.9) nmol/L, FIN (25.2 +/- 3.8) mU/L and HOMA IR (1.56 +/- 0.25) in group A were significantly higher than those of group B (13.9 +/- 1.9) U/L, 2.3 +/- 0.4, (3.6 +/- 0.4) nmol/L, (13.4 +/- 3.8) mU/L, 0.87 +/- 0.28 and control group (7.3 +/- 2.1) U/L, 1.3 +/- 0.3, (0.9 +/- 0.2) nmol/L, (9.5 +/- 2.6) mU/L, 0.50 +/- 0.30 (all P < 0.05); (2) The protein expression and tyrosine phosphorylation of IRS-1 in group A (690 +/- 19 and 528 +/- 72 respectively) were significantly lower than those in group B (892 +/- 31, 801 +/- 64) and control group (988 +/- 29, 1139 +/- 124) (P < 0.05, and P < 0.01 respectively). (3) Insulin resistance index in group A and group B were negatively related with protein expression and tyrosine phosphorylation (r = -0.52, P < 0.05; r = -0.61, P < 0.01 and r = -0.60, P < 0.05; r = -0.63, P < 0.05). CONCLUSIONS: The signal transduction malfunction because of protein expression and tyrosine phosphorylation changes of IRS-1 in adipose tissue from polycystic ovary syndrome patients may be one of the mechanisms leading to insulin resistance.

Reduced amount of cytochrome c oxidase subunit I messenger RNA in placentas from pregnancies complicated by preeclampsia.

BACKGROUND: Cytochrome c oxidase is a marker enzyme of the mitochondrial inner membrane. A change in the structure and activity of cytochrome c oxidase may alter the electron transport in the inner membrane, leading to insufficient adenosine triphosphate (ATP) production. ATP is essential for maintaining the function of cells. The aim of this study was to compare the expression of cytochrome c oxidase subunit I mRNA in placentas from normal and preeclamptic pregnancies. METHODS: By means of in situ hybridization, frozen sections of placentas from 23 women with preeclampsia and 29 women with uneventful pregnancies were examined. Digoxigenin (DIG)-labeled probes were used to detect the expression of cytochrome c oxidase subunit I mRNA in the placentas. The expression density was assessed by using an image disposal and analysis system. RESULTS: Positive expression of cytochrome c oxidase subunit I mRNA was found in the cytoplasm of villous syncytiotrophoblasts. The mean light density of cytochrome c oxidase subunit I mRNA in placental villi of normal pregnant women was 0.2638, and 0.1763 in women with preeclampsia, a statistically significant difference (P < 0.05). The number density of cytochrome c oxidase subunit I mRNA in placental villi was also significantly reduced in preeclamptic women compared with the control group (P < 0.05). CONCLUSIONS: Our study demonstrates a reduced amount of cytochrome c oxidase subunit I mRNA in preeclamptic placentas compared to control placentas. We hypothesize that a reduced expression may play a role in the pathophysiology of preeclampsia.

Expression of resistin mRNA in adipose tissue of rat model with polycystic ovarian syndrome and its implication.

To investigate the relationship between the insulin resistance (IR) of polycystic ovarian syndrome (PCOS) rat model induced by dehydroeplandrosterone (DHEA) and hormonal changes in the ovarium and the resistin mRNA levels in adipose tissue, 21-day-old female SD rats were divided into two groups in pairs. The rats in group 1 were injected daily (s.c.) with DHEA for up to 20 days and the rats in group 2 injected with oil at the same time. Ovarian weight, serum insulin levels and sex hormone levels in rat blood of both groups were determined. Oral glucose tolerance tests, light microscopic and electronic microscopic examination were performed. The levels of resistin mRNA in adipose tissue were measured by reverse transcription-polymerase chain reaction (RT-PCR). Our results showed that the ovarian weight in group 1 was greater than that in group 2 (P<0.05). The ovaria in group 1 showed multiple follicular cysts, The serum testeosterone and etrasdiol concentration were significantly higher in group 1 than those in group 2 (P<0.001 and P<0.05 respectively), so as the fasting serum glucose (P<0.001) and fasting serum insulin (P<0.05). The value of 1/FINS x FGC was significantly higher in group 1 than that in group 2 (P<0.001). Moreover, the resistin mRNA level of white adipose tissue in the DHEA-induced group was significantly higher than that in the control rats (P<0.05). It is concluded that the DHEA-induced PCOS rat models were similar to those of the patients with PCOS, and the IR was observed. Resistin secreted by adipose tissue may mediate IR in PCOS, and it is likely involved in the pathogenesis and development of PCOS.

Expression of survivin in early villus and decidua and its implication.

To investigate the expression and implication of survivin protein and mRNA in decidua and villus and the effects of mifepristone on its expression, survivin levels in decidua and villus collected from 15 normal early pregnant women and 15 early pregnant women pretreated with 150 mg mifepristone and 400 micrograms misoprostol were assessed by immuno-histochemical techniques and reverse transcriptional-polymerase chain reaction (RT-PCR). Our results showed that survivin proteins were stained in the cytoplasm of trophoblasts and decidual cells and in the nuclei of some of the decidual glandular epithelial cells. The expression was strongest in the trophoblasts and decidual glandular epithelial cells. The expression values in the villus and decidua were (14.56 +/- 2.44) and (10.46 +/- 2.81) respectively for normal pregnant and (8.45 +/- 2.08), (7.33 +/- 1.91) for those pretreated with mifepristone respectively (P < 0.05). The transcription of survivin mRNA in villus and decidua of those pretreated with mifepristone decreased significantly compared with those in the normal pregnant women (P < 0.05). It is concluded that survivin can be expressed in the decidua and villus and mifepristone inhibits its mRNA transcription and protein expression, which could possibly be one of the factors inducing decidual and villous apoptosis.

Expression of c-erbB2 in gestational trophoblastic disease and its clinical significance.

In order to explore a potential indicator of predicting the occurrence and development of gestational trophoblastic tumor, the expression of c-erbB2 oncogene in human normal placenta, hydatidiform mole and choriocarcinoma was investigated. The expression of c-erbB2 was detected immunohistochemically by monoclonal antibody against the gene on the formalin-fixed paraffin sections of 21 hydatidiform moles, 21 invasive moles, 20 choriocarcinomas and 30 normal placentas. Results showed that the expression level of c-erbB2 was significantly higher in gestational trophoblastic tumor than in hydatidiform mole and normal placenta of midterm and term pregnancy (P < 0.05), while there was no significant difference between patients with gestational trophoblastic tumor of stage III, IV and those of stage I, II. It was demonstrated that overexpression of c-erbB2 may closely associated with malignant transformation of hydatidiform mole, not only providing important insight into pathogenesis of gestational trophoblastic tumor, but also having an important significance for the early diagnosis and early treatment of gestational trophoblastic tumor.

Different imprinting status of IGF-2 in epithelial ovarian tumors.

To explore whether the imprinting status of IGF-2 in the malignant epithelial ovarian tumors is different from that in benign tumors, the target sequences (DNA and RNA) which contain a polymorphism site for ApaI restriction endonuclease digestion were amplified with PCR and RT-PCR methods. Then the PCR/RT-PCR products were digested by ApaI. The IGF-2 transcriptional pattern came out from the results of endonucleases digestion. Among the 36 cases of benign epithelial ovarian tumors, 20 were heterozygous for ApaI locus and all showed genomic imprinting. While in the malignant group, 22 were heterozygous for ApaI locus but six were found to lose imprinting. Significant differences existed between the two groups (P < 0.05). Loss of imprinting of IGF-2 may serve as a marker for differentiating the malignant ovarian cancers from the benign ones. In a new field of molecular genetics, our research provides an experimental basis for genetic diagnosis and treatment of the ovarian cancers.