Deep Underground Laboratory Measurement of ^{13}C(α,n)^{16}O in the Gamow Windows of the s and i Processes

The ^{13}C(α,n)^{16}O reaction is the main neutron source for the slow-neutron-capture process in asymptotic giant branch stars and for the intermediate process. Direct measurements at astrophysical energies in above-ground laboratories are hindered by the extremely small cross sections and vast cosmic-ray-induced background. We performed the first consistent direct measurement in the range of E_{c.m.}=0.24 to 1.9 MeV using the accelerators at the China Jinping Underground Laboratory and Sichuan University. Our measurement covers almost the entire intermediate process Gamow window in which the large uncertainty of the previous experiments has been reduced from 60% down to 15%, eliminates the large systematic uncertainty in the extrapolation arising from the inconsistency of existing datasets, and provides a more reliable reaction rate for the studies of the slow-neutron-capture and intermediate processes along with the first direct determination of the alpha strength for the near-threshold state.

[Effects of obstructive sleep apnea hypopnea syndrome on cardiac function in patients with chronic obstructive pulmonary disease]

Objective: To analyze the clinical characteristics of patients with chronic obstructive pulmonary disease (COPD) and COPD overlapping obstructive sleep apnea hypopnea syndrome (overlap syndrome), and to study the relationship between overlap syndrome and cardiovascular diseases. Methods: A total of 126 stable COPD patients admitted to the Respiratory Department of Peking University Third Hospital from September 2016 to October 2018 were included in this study, including 112 males and 14 females, ranging in age from 48 to 89 years, with a median of 67 years. With apnea hypopnea index (AHI) 5 times/h for the cutoff value, we classified the patients into a simple COPD group (31 cases) and an overlap syndrome group (95 cases), and compared the patients' demographic characteristics, respiratory symptoms, lung function, the incidence of cardiovascular events and the cardiac function with echocardiography (E/e'), left atrium diameter (LAD) and left ventricular ejection fraction (LVEF), by using independent-samples T test and chi-square test. Results: There were no statistically significant differences in demographic characteristics, respiratory symptoms, pulmonary function, cardiac function between COPD patients and overlap syndrome patients, but significant differences in blood oxygen level at night and left ventricular mass index(LVMI) between these groups (P=0.014,P<0.001,P<0.001,P<0.001, P=0.047, respectively) were observed. By comparing the severe sleep apnea hypopnea syndrome (AHI≥30) with sleep apnea hypopnea syndrome patients(AHI<30), there were statistically significant differences in echocardiographic indicators, among which there were statistically significant differences in E/e'(P=0.013), LAD(P=0.006), LVMI (P=0.051) and LVEF (P=0.030).There were also significant differences in the history of coronary heart disease and congestive heart failure between the two groups (P=0.025, P<0.001). After dividing the patients with overlap syndrome by mild, moderate and severe severity, E/e' and LAD were significantly correlated with severity (P=0.045, P=0.011). In terms of blood oxygen level at night, there was a significant correlation between average blood oxygen saturation at night and E/e', LAD, and LVMI (r=-0.195, P=0.033; r=-0.197, P=0.030; r=-0.195, P=0.044); moreover, there was also a significant correlation between the ratio of blood oxygen≤90% and LAD (r=0.209, P=0.021). In the multiple linear regression model, E/e' increased by 0.070 on average for each unit increase in AHI, and 0.084 on average for each unit increase in oxygen desaturation index (ODI). Conclusions: Patients with COPD overlapping severe sleep apnea hypopnea syndrome showed worse left diastolic function and higher risk of congestive heart failure and coronary heart disease compared with the patients with COPD alone. In addition, the degree of impairment of left heart diastolic function was associated with the severity of COPD overlapping sleep apnea hypopnea syndrome. The higher the AHI and the ODI became, the more severe the left heart diastolic restriction and structures changed.

Direct Measurement of the Astrophysical ^{19}F(p,αγ)^{16}O Reaction in the Deepest Operational Underground Laboratory

Fluorine is one of the most interesting elements in nuclear astrophysics, where the ^{19}F(p,α)^{16}O reaction is of crucial importance for Galactic ^{19}F abundances and CNO cycle loss in first generation Population III stars. As a day-one campaign at the Jinping Underground Nuclear Astrophysics experimental facility, we report direct measurements of the essential ^{19}F(p,αγ)^{16}O reaction channel. The γ-ray yields were measured over E_{c.m.}=72.4-344  keV, covering the Gamow window; our energy of 72.4 keV is unprecedentedly low, reported here for the first time. The experiment was performed under the extremely low cosmic-ray-induced background environment of the China JinPing Underground Laboratory, one of the deepest underground laboratories in the world. The present low-energy S factors deviate significantly from previous theoretical predictions, and the uncertainties are significantly reduced. The thermonuclear ^{19}F(p,αγ)^{16}O reaction rate has been determined directly at the relevant astrophysical energies.

[Effects of alprostadil in β-aminopropanitrile induced aortic dissection in a murine model]

Objective: To investigate the protective role of alprostadil on aortic dissection. Methods: 26 C57BL6 male mice were divided into control group (normal drinking water, n=13) and model group (1 g·kg^-1·d^-1 BAPN via drinking water, n=13). On day 14, mRNA expression of inflammatory-related genes as well as EP receptor families were detected by RT-PCR (n=6 each) and EP4 protein levels were determined by Western blot (n=7 each). Another 88 mice were divided into 3 groups: control group (n=22), model group (n=33) and treatment group (n=33). The mice in model group and treatment group were applied with BAPN (1 g·kg^-1·d^-1) via drinking water. The mice in treatment group received additional intraperitoneal injection with alprostadil (80 μg·kg^-1·d^-1) for 28 days. The mice in the control and model group received equal volume intraperitoneal injection with 0.9% saline respectively. The body weight and systolic blood pressure, the mortality and morbidity were monitored from the beginning until the designed end of the study. On day 28, the mice were sacrificed and aorta were fixed, embedded and sliced, followed by staining with HE and Victoria Blue. The distribution of EP4 was determined by immunohistochemistry in control (n=6) and model group (n=6). Furthermore, the concentration of PGE1 were tested among model (n=3) and treatment group (n=4). EP4 protein expression was determined in model group (n=7) and treatment group (n=6). Results: On day 14, mRNA expression level of MCP-1 ((2.74±1.55) vs. (1.00±0.49),<0.05) and MMP2((1.38±0.42) vs. (1.00±0.27), P<0.05) was significantly upregulated in model group compared with control group. Protein expression of EP4 receptor also increased in aorta in model group compared with control group (1.48±0.51 vs. 1.00±0.19, P<0.05). In the dissection area, the EP4 expression was also enriched compared with non-dissection area, particularly in endothelial cells and inflammatory cells on day 28. BAPN applied in drinking water (model and treatment groups) successfully induced the aortic dissection in mice, some mice died of the rupture. The elastic fibers were fractured, and the infiltrated immune cells were visible in dissected tissue. False lumen was formed. There was no dissection and death in the control group. Compared with control group, the morbidity and mortality rates were significantly increased in the model group (60.6%, 20/33, 30.3%, 10/33) and the treatment group (72.7%, 24/33, 24.2%, 8/33). The mortality and morbidity rates were similar between model and treatment groups. There is no difference in terms of SBP among three groups (P>0.05). Further study showed that after alprostadil injection, the blood concentration of PGE1 was increased in treatment group ((0.540±0.041 vs. 0.436±0.012)μmol/L, P<0.05). Besides, the EP4 receptor expression was downregulated in the treatment group compared to model group (0.60±0.30 vs. 1.00±0.20, P<0.05). Conclusion: EP4 expression is upregulated in BAPN induced aortic dissection mouse model. No protective effects are observed post alprostadil treatment in this model probably due to the reduced expression of EP4.

Effects of residual superdoses of phytase on growth performance, tibia mineralization, and relative organ weight in ducks fed phosphorus-deficient diets

This study was conducted to determine the effects of residual superdoses of phytase on growth performance, tibia mineralization, and relative organ weight in ducks fed phosphorus-deficient diets. In Exp. 1, 4 kinds of commercial phytase were used to determine retention rate of phyatse with the phytase C being the highest via both high water-bath temperature (90%) and pelleting (50%), followed by phytase A, B, and D. In Exp. 2, a total of 560 male ducks were blocked based on body weight, and then allocated randomly to 7 treatments (5 replicates with 16 birds per replicate). Treatments included a maize-soybean meal-based diet with recommended calcium and 4.0 g non-phytate phosphorus (nPP)/kg starter diet or 3.8 g nPP/kg grower diet (positive control; PC), an nPP-deficient diet with 1.3 g nPP/kg starter diet or 1.1 g nPP/kg grower diet (negative control; NC), NC diets with increasing levels of residual phytase C (500, 1,000, 2,000, 3,000, and 4,000 units/kg feed) after pelleting. Birds fed NC diets had lower (P < 0.05) average daily gain (ADG) and average daily feed intake (ADFI) throughout the experiment compared with those fed PC diet. Supplementing NC diet with increasing residual superdoses of phytase improved (P < 0.05) ADG and ADFI quadratically in the entire experiment, while reduced feed-to-gain ratio (P < 0.05) quadratically during day 0 to 14. On day 14 and 35, birds fed NC diet had lower (P < 0.05) tibia length, weight, ash, calcium, phosphorus, and manganese contents than those fed PC diet. Increasing residual superdoses of phytase in NC diet increased (P < 0.05) tibia weight and ash, calcium, phosphorus contents quadratically on day 14 and 35. NC treatment increased (P < 0.05) the duodenum, jejunum, ileum, and cecum index compared with other treatments on day 14 and 35. Taken together, feeding increasing residual superdoses of phytase could counteract or exceed the negative effects of NC diet on growth performance, tibia mineralization, and relative organ weight in ducks.

Ambra1 inhibits paclitaxel-induced apoptosis in breast cancer cells by modulating the Bim/mitochondrial pathway

Cancer cells often evade apoptosis induced by anti-cancer drugs, which reduces the efficacy of the drugs. Autophagy/Beclin 1 regulator 1 (Ambra1) is a crucial proautophagic protein. It also plays an important role in the execution of apoptosis. However, the mechanism by which Ambra1 regulates apoptosis has not been fully clarified. Moreover, whether Ambra1 participates in the regulation of paclitaxel-induced apoptosis in breast cancer cells is not clear. Here, we show that Ambra1 inhibits paclitaxel-induced apoptosis in breast cancer cells. Moreover, Bim and mitochondria are key effectors of Ambra1 in this process. Thus, Ambra1 is a protein that makes breast cancer cells resistant to apoptosis by modulating the Bim/mitochondrial pathway. Therefore, Ambra1 may be a potential target for the treatment of breast cancer.

[Effects of preoperative percutaneous transhepatic biliary drainage on surgical treatment of type Ⅲ and Ⅳ hilar cholangiocarcinoma]

Objective: To investigate the effects of preoperative percutaneous transhepatic biliary drainage on surgical treatment of type Ⅲ and Ⅳ hilar cholangiocarcinoma. Methods: Clinical data of 72 patients with hilar cholangiocarcinoma of the Bismuth-Corlette type Ⅲ and Ⅳ treated at Department of General Surgery,First Affiliated Hospital of Bengbu Medical College from January 2010 to December 2017 were analyzed retrospectively.Patients were divided into two groups based on whether PTBD was performed:a drained group and an undrained group.In the drained group,there were 31 patients,20 males and 11 females,aged (59.9±9.7)years (range: 39-73 years).Among them,14 patients underwent hepatectomy with half or more than half of the liver removed (extended hepatectomy)and 17 patients underwent non-anatomical hepatectomy in the hilar region (limited hepatectomy).In the undrained group,there were 41 patients, 26 males and 15 females, aged (60.8±7.8)years(range: 45-75 years).Among them, 17 patients underwent hepatectomy with half or more than half of the liver removed (extended hepatectomy)and 24 patients underwent non-anatomical hepatectomy in the hilar region (limited hepatectomy).Percutaneous transhepatic biliary drainage(PTBD)was used in the drained group.Under the guidance of ultrasound,one or more hepatobiliary ducts could be sufficiently drained,which had good effect and was not restricted by the obstruction location of hilar cholangiocarcinoma.The analysis of the measurement data was performed using t test,and the analysis of the count data was performed using χ(2) test,and the survival curve was plotted using Kaplan-meier method. Results: In total, 72 jaundiced patients with hilar cholangiocarcinoma underwent surgical treatment: 31 had PTBD prior to operation while 41 did not had PTBD.There were significant differences in ALT((93.2±21.4)U/L vs.(207.4±65.1)U/L),AST((87.6±18.1)U/L vs.(188.9±56.6)U/L)and total bilirubin((68.8±12.6)μmol/L vs.(227.5±87.7)μmol/L)between the patients after treatment and those before treatment(t=10.958, P=0.000; t=10.845, P=0.000; t=10.386, P=0.000).Compared with those in the undrained group, the operation time was shorter, the amount of intraoperative bleeding and the incidence of complications were lower in the drained group(t=-2.840, P=0.006; t=-3.698, P=0.000; χ(2)=4.108, P=0.043).There were no perioperative death cases in drained group and 2 perioperative death cases in undrained group.There was no significant difference in R0 resection rate between the two groups(χ(2)=0.778,P=0.378).The 1-,3-,5-year survival rate of patients in the drained group and the undrained group was 72.7%,34.2%, 13.7% and 72.8%, 31.5%, 11.8%, respectively.The difference was not statistically significant(all P>0.05). Conclusions: The preoperative percutaneous transhepatic biliary drainage in patients with hilar cholangiocarcinoma of Bismuth-Corlette type Ⅲ and Ⅳ could effectively shorten operative time, reduce amount of intraoperative bleeding and incidence of postoperative complications,but have no significant effect on the R0 resection rate and survival rate.

Fully integrated silicon probes for high-density recording of neural activity

Sensory, motor and cognitive operations involve the coordinated action of large neuronal populations across multiple brain regions in both superficial and deep structures. Existing extracellular probes record neural activity with excellent spatial and temporal (sub-millisecond) resolution, but from only a few dozen neurons per shank. Optical Ca2+ imaging offers more coverage but lacks the temporal resolution needed to distinguish individual spikes reliably and does not measure local field potentials. Until now, no technology compatible with use in unrestrained animals has combined high spatiotemporal resolution with large volume coverage. Here we design, fabricate and test a new silicon probe known as Neuropixels to meet this need. Each probe has 384 recording channels that can programmably address 960 complementary metal-oxide-semiconductor (CMOS) processing-compatible low-impedance TiN sites that tile a single 10-mm long, 70 × 20-μm cross-section shank. The 6 × 9-mm probe base is fabricated with the shank on a single chip. Voltage signals are filtered, amplified, multiplexed and digitized on the base, allowing the direct transmission of noise-free digital data from the probe. The combination of dense recording sites and high channel count yielded well-isolated spiking activity from hundreds of neurons per probe implanted in mice and rats. Using two probes, more than 700 well-isolated single neurons were recorded simultaneously from five brain structures in an awake mouse. The fully integrated functionality and small size of Neuropixels probes allowed large populations of neurons from several brain structures to be recorded in freely moving animals. This combination of high-performance electrode technology and scalable chip fabrication methods opens a path towards recording of brain-wide neural activity during behaviour.

[Efficiency of FibroScan and FibroTouch in liver stiffness measurement and fat quantification: a comparative analysis]

Objective: To investigate the efficiency of FibroScan(FS)and FibroTouch(FT)in liver stiffness measurement(LSM)and fat quantification through a comparative analysis. Methods: The outpatients or hospitalized patients who underwent LSM and fat quantification using FS and FT were enrolled. The differences in success rate and detecting parameters between FS and FT were analyzed, as well as the correlation between FS and FT values. The t-test was used for comparison of normally distributed continuous data between groups, and a one-way analysis of variance or the Kruskal-Wallis test was used for comparison between multiple groups. The Mann-Whitney U test was used for comparison of non-normally distributed continuous data between groups. Results: A total of 1621 patients were enrolled. The success rates of FT and FS were 100% and 94.96%, respectively, and the success rate of FS was influenced by sex, age, body mass index, and biochemical markers of liver function. FT has a significantly shorter duration of single detection and a significantly lower number of times of single detection than FS(duration of single detection: 190.21±38.78 s vs 220.89±68.36 s, P < 0.01; number of single detection times: 10.31±1.32 vs 11.81±3.76, P < 0.01), as well as a significantly lower ratio of interquartile range to median of fat quantification in the same patient(5.39%±4.81% vs 17.18%±14.07%, P < 0.01). The LSM and fat quantification of FS were significantly correlated with those of FT(r = 0.645 and 0.620, both Based on the duration and number of times of single detection, success rate, and stability of fat quantification, FT seems to have a better detection efficiency than FS. The detection values of FT and FS can be calculated with regression equations < 0.01). The equations of linear regression were LSM(FT)= 4.435+0.477×LSM(FS); CAP(FT)= 134.71+0.456×CAP(FS). Conclusion: Based on the duration and number of times of single detection, success rate, and stability of fat quantification, FT seems to have a better detection efficiency than FS. The detection values of FT and FS can be calculated with regression equations.

Enhanced hydrogen adsorption on graphene by manganese and manganese vanadium alloy decoration

In this work, two kinds of novel manganese decorated (G + Mn) and manganese-vanadium co-decorated (G + MnV) graphene composites are synthesized by in situ wet chemical reduction, and their hydrogen storage properties and microstructures are characterized by Sievert-type adsorption apparatus, BET, SEM, TEM/STEM, EDX and EELS. Compared with pristine graphene, Mn decoration marginally increases the hydrogen adsorption capacity of graphene at room temperature and 4 MPa hydrogen pressure from 0.25 wt% to 0.36 wt%. On the other hand, the co-decoration of Mn and V increases the room temperature hydrogen storage capacity of graphene significantly to 1.81 wt% under 4 MPa hydrogen pressure, which is 1.56 wt% higher than the capacity of pristine graphene. The microstructures and valence states of the decorated Mn and Mn-V nanoparticles are investigated by TEM, EDX and EELS analyses, and strong interactions between the decorated nanoparticles and graphene are observed. Based on the results from structural analyses, potential enhancement mechanisms are suggested in terms of the catalytic effects of nanoparticles on graphene hydrogen adsorption. Given the relatively low cost of Mn and V metals compared to noble metals such as Pd, Pt and Au, these results demonstrate a low cost and effective way to significantly enhance the room temperature hydrogen adsorption properties of graphene for potential hydrogen storage applications.

[A serum lipidomic study of patients with non-alcoholic fatty liver disease]

Objective: To investigate the serum lipidomic profile in patients with nonalcoholic fatty liver disease (NAFLD), and to analyze the lipid metabolism characteristics of NAFLD. Methods: The subjects were divided into control group (23 patients) and pathologically confirmed NAFLD group (42 patients), and ultra-high-performance liquid chromatography-tandem mass spectrometry was used to measure serum lipidomic metabolites. The partial least squares-discriminant analysis (PLS-DA) model was established to analyze the differences in lipid metabolism with reference to the univariate analysis. The t-test and Mann-Whitney U test were used for data analysis. Results: A total of 239 lipids were identified and qualitative and quantitative analyses were performed. The PLS-DA model (R2 = 0.753, Q2 = 0.456) and the univariate analysis showed that 77 lipids were metabolized differentially between the NAFLD group and the control group (VIP > 1, P < 0.05), including free fatty acid, phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, lysophosphatidylcholine, lysophosphatidylinositol (LPI), choline plasmalogen (PlsCho), ethanolamine plasmalogen (PlsEtn), ceramide (Cer), sphingomyelin, and triglyceride (TG). Compared with the control group, the NAFLD group had significant increases in monounsaturated fatty acids (increased by 39%, t = -3.954, P < 0.05) and TGs (increased by 36%, Z = -2.662, P < 0.05), mainly TGs with low numbers of carbon atoms and unsaturated bonds, while there were reductions in TGs with high numbers of carbon atoms and unsaturated bonds. In addition, compared with the control group, the NAFLD group had significant increases in the levels of LPI (increased by 223%, t = -3.858, P < 0.05) and Cer (increased by 21%, t = -2.481, P < 0.05) and significant reductions in PlsCho (reduced by 18%, t = 3.184, P < 0.05) and PlsEtn (reduced by 20%, t = 2.363, P < 0.05). Conclusion: There is a significant difference in lipid metabolism profile between NAFLD patients and healthy people, and a serum lipidomic analysis of NAFLD helps to further clarify the characteristics of lipid metabolism in patients with NAFLD.

[A clinical study of the association between hepatic controlled attenuation parameter and metabolic syndrome]

Objective: To investigate the association between hepatic controlled attenuation parameter (CAP) and metabolic syndrome (MetS) and the correlation of CAP and its changes with the incidence of MetS. Methods: A total of 2461 subjects who underwent physical examination from July 2013 to September 2015 were enrolled. Spearman correlation analysis was used to investigate the correlation of CAP with the number of MetS components and each MetS component, and the chi-square test was used to investigate the prevalence rates of MetS and each component under different CAP levels. Logistic regression analysis was used to analyze the odds ratio (95% confidence interval (CI)) of MetS under different CAP levels. A total of 230 subjects without baseline MetS were selected; in a prospective cohort study, these subjects were divided into groups according to the baseline CAP, change in CAP, and percent change in CAP, and the chi-square test was performed to compare the incidence of MetS. The Cox regression analysis was used to analyze the values of baseline CAP, change in CAP, and percent change in CAP in predicting MetS. Results: CAP was positively correlated with the number of MetS components (r = 0.309, P < 0.01) and significantly correlated with all components. There were significant differences in the prevalence rates of MetS and its components under different CAP levels (< 238 dB/m, 238-258 dB/m, 259-291 dB/m, and ≥292 dB/m) (P < 0.05). After the adjustment for sex and age, with < 238 dB/m as a reference, the odds ratios (95% CI) of MetS in patients with CAP levels of 238-258 dB/m, 259-291 dB/m, and ≥292 dB/m were 1.784 (1.369-2.325), 2.936 (2.292-3.760), and 4.363 (3.435-5.543), respectively (all P < 0.05). Follow-up data showed that 28 patients (12.2%) developed MetS. After the adjustment for related factors, the hazard ratios (95% CI) of MetS in patients with baseline CAP > 238 dB/m, change in CAP > 30 dB/m, and percent change in CAP > 25.0% were 3.337 (1.163-9.569), 7.732 (2.453-24.366), and 11.656 (3.329-40.813), respectively (all P < 0.05). Conclusion: CAP is closely associated with MetS and its components. CAP and its change can be used to predict the risk of MetS.

Autophagy facilitates multidrug resistance development through inhibition of apoptosis in breast cancer cells

Acquired multidrug resistance (MDR) is the main mechanism of chemotherapeutic drugs resistance. Nevertheless, the mechanisms of MDR are complex and still not very clear. Recently, including our previous study, several studies have revealed that macroautophagy (here referred to as autophagy) induced by anti-cancer drugs in breast cancer cells may facilitate the development of resistance to epirubicin (EPI), paclitaxel (PTX), tamoxifen or herceptin. Whereas there are a few studies on the relationship between autophagy and MDR, especially the studies designed directly employing induced resistant breast cancer cells. Based on previous study, we explored the relationship between autophagy and MDR. The results showed that induced EPI-resistant MCF-7er and SK-BR-3er cells were simultaneously resistant to PTX and vinorelbine (NVB), which demonstrated that the cells obtained MDR phenotype. Furthermore, PTX and NVB could also induce autophagy in MCF-7er and SK-BR-3er cells, and the induced autophagy protected the cells from apoptosis, which facilitated the development of resistance to PTX and NVB. Thus, autophagy promoted the development of MDR in breast cancer cells through inhibition of apoptosis. In addition, we found that P-glycoprotein (Pgp) was overexpressed in MCF-7er and SK-Br-3er cells. And we preliminarily investigated the relationship between autophagy and P-glycoprotein (Pgp). The results showed that the expression of the protein did not obviously change despite the inhibition of autophagy. Therefore, the role of Pgp in the development of MDR might be independent of autophahy. Also this finding implies that autophagy might be a target to overcome MDR in breast cancer cells, and clinical use autophagy inhibitors might be one of the important strategies for overcoming MDR in breast cancer therapy.

KEYWORDS

Autophagy, apoptosis, multidrug resistance, breast cancer, chemotherapy.

Effect of supplementation of organic manganese on reproductive performance of female Ussuri raccoon dogs (Nyctereutes procyonoides) during the breeding season

The study was conducted to investigate the effect of dietary manganese (Mn) on reproductive performance of female Ussuri raccoon dogs (Nyctereutes procyonoides) during the breeding season. Healthy female Ussuri raccoon dogs (n=72) were randomly divided into six groups of twelve each. The six experimental diets were formulated to contain graded amounts of Mn (0, 40, 80, 120, 200 and 400mg/kg of diet; Groups A through F, respectively). Litter size of Group D was greater than that of Groups A, B, C and E (P<0.05), with Group E having the smallest litter size. Values of number born alive were affected by different amounts of organic Mn. Number of pups born alive in Group D was greater than that of Groups B, C, E and F (P<0.05). Number of pups weaned alive for Group D was greater than that of Groups A, B, C and E (P<0.05). Mn supplementation of the control diet (containing 24.32 mg/kg from raw materials) with 120 mg/kg of Mn was adequate for female Ussuri raccoon dogs during the breeding season, based on positive effects of reproduction performance.

Fluorescence evolution of leachates during treatment processes from two contrasting landfills

Landfill leachates are composed of a complex mixture of organic matter, including a wide range of potentially fluorescent organic compounds. The fluorescence excitation-emission matrix (FEEM) of leachates during treatment processes is investigated. Particular attention is paid to the fluorescence evolution of leachates during treatment processes. Two typical types of landfill, landfill A (a direct municipal solid waste (MSW) landfill) and landfill B (disposal of bottom ashes from MSW incinerators), in a city in Southern China were selected. The results show that two characteristic and intense excitation-emission peaks located at Ex/Em = 310-330 nm/395-410 nm (peak alpha) and Ex/Em = 250-260 nm/450-460 nm (peak alpha') are observed. As the aromatic chemicals, capable of emitting fluorescence, are more recalcitrant to biodegradation than aliphatic chemicals, enhancement of the dissolved organic carbon normalized fluorescence intensities is demonstrated during treatment processes of leachate A and leachate B. This is confirmed by the variation of ultraviolet absorptivity of leachates at 254 nm. Peak alpha' and peak alpha are attributed to a mixture of xenobiotic organic compounds with low molecular weight and relatively stable aromatic fulvic-like matters with high molecular weight, respectively. Humic substances are more resistant to biodegradation than xenobiotic organic compounds, so a significant reduction in the Ialpha'/Ialpha values (fluorescence intensity ratios of peak alpha' and peak a) of leachate A was observed during treatment processes. However, no evident variation for the Ialpha/Ialpha values of leachate B was found during treatment processes owing to the low concentrations of xenobiotic organic compounds in leachate B after incineration.

Fluorescence of sediment humic substance and its effect on the sorption of selected endocrine disruptors

Humic substances (HS) have a critical influence on the sorption of organic contaminants by soils and sediments. This paper describes investigations into the sorption behavior of three representative endocrine disruptors, bisphenol A (BPA), 17beta-estradiol (E2), and 17alpha-ethynylestradiol (EE2), onto sediments and HS extracted sediments using a batch technique. The organic carbon-normalized partition coefficients (K(oc)) for the extracted HS (K(oc)(hs)) were calculated, and the fluorescence spectra of the HS extraced from different sediment samples were gained using excitation/emission matrix (EEM). Particular attention was paid to the correlations between the fluorescence characteristics of HS and the log K(oc)(hs) of selected endocrine disruptors. The results show that the log K(oc)(hs) values range from 3.14 to 4.09 for BPA, from 3.47 to 4.33 for E2, and from 3.65 to 4.32 for EE2. Two characteristic excitation-emission peaks were observed for HS samples extracted from sediments. They are located at Ex/Em=250-260 nm/400-450 nm (peak alpha') and Ex/Em=310-330 nm/390-400 nm (peak alpha) respectively. The alpha' and alpha peak relative intensities I(alpha')/I(alpha) vary from 0.46 to 1.64 for different extracted HS samples. The similarity between fulvic acids (FA) Ex/Em pairs and those observed for HS indicates that FA is the predominant fraction of HS extracted from sediments. Moreover, the log K(oc)(hs) values of BPA, E2, and EE2 have a negative linear correlation to I(alpha')/I(alpha) values. Peak alpha is often attributed to relatively stable and high molecular weight aromatic fulvic-like matter. Therefore, the result presented here reveals that the abundance of aromatic rings in HS molecular structure plays a critical role in the sorption of selected endocrine disruptors.

A high-resolution radiation hybrid map of the human genome draft sequence

We have constructed a physical map of the human genome by using a panel of 90 whole-genome radiation hybrids (the TNG panel) in conjunction with 40,322 sequence-tagged sites (STSs) derived from random genomic sequences as well as expressed sequences. Of 36,678 STSs on the TNG radiation hybrid map, only 3604 (9.8%) were absent from the unassembled draft sequence of the human genome. Of 20,030 STSs ordered on the TNG map as well as the assembled human genome draft sequence and the Celera assembled human genome sequence, 36% of the STSs had a discrepant order between the working draft sequence and the Celera sequence. The TNG map order was identical to one of the two sequence orders in 60% of these discrepant cases.

An STS-based radiation hybrid map of the human genome

We have constructed a physical map of the human genome by using a panel of 83 whole genome radiation hybrids (the Stanford G3 panel) in conjunction with 10,478 sequence-tagged sites (STSs) derived from random genomic DNA sequences, previously mapped genetic markers, and expressed sequences. Of these STSs, 5049 are framework markers that fall into 1766 high-confidence bins. An additional 945 STSs are indistinguishable in their map location from one or more of the framework markers. These 5994 mapped STSs have an average spacing of 500 kb. An additional 4484 STSs are positioned with respect to the framework markers. Comparison of the orders of markers on this map with orders derived from independent meiotic and YAC STS-content maps indicates that the error rate in defining high-confidence bins is < 5%. Analysis of 322 random cDNAs indicates that the map covers the vast majority of the human genome. This STS-based radiation hybrid map of the human genome brings us one step closer to the goal of a physical map containing 30,000 unique ordered landmarks with an average marker spacing of 100 kb.

A gene map of the human genome

The human genome is thought to harbor 50,000 to 100,000 genes, of which about half have been sampled to date in the form of expressed sequence tags. An international consortium was organized to develop and map gene-based sequence tagged site markers on a set of two radiation hybrid panels and a yeast artificial chromosome library. More than 16,000 human genes have been mapped relative to a framework map that contains about 1000 polymorphic genetic markers. The gene map unifies the existing genetic and physical maps with the nucleotide and protein sequence databases in a fashion that should speed the discovery of genes underlying inherited human disease. The integrated resource is available through a site on the World Wide Web at http://www.ncbi.nlm.nih.gov/SCIENCE96/.

Effects of drug discrimination history on the generalization of pentobarbital to other drugs

In pigeons trained to discriminate between pentobarbital and saline, pentobarbital, amobarbital and diazepam substituted for pentobarbital, whereas phencyclidine (PCP) substituted in part for pentobarbital and d-amphetamine, morphine and drug vehicles did not substitute. After morphine replaced pentobarbital as the training drug (group A), morphine, pentobarbital and diazepam substituted, PCP substituted in part, but not d-amphetamine, haloperidol and vehicles. After d-amphetamine replaced pentobarbital as the training drug (group B), d-amphetamine, pentobarbital and diazepam substituted, PCP substituted in part, but not haloperidol, morphine and vehicles. Next, morphine and d-amphetamine were reversed as training drugs for the two groups. In group A, morphine, d-amphetamine, pentobarbital and diazepam substituted, PCP substituted in part, but not haloperidol and vehicles. Similar effects were observed in group B. Next, birds in group A were reinforced for responses on the drug key (red key) after d-amphetamine and on the previous saline key (green key) after pentobarbital. In group B, morphine continued as the training drug for the red key, whereas responses on the green key were reinforced after pentobarbital. In group A, d-amphetamine, morphine, d-pentazocine and to some extent PCP, produced responding on the red key, whereas pentobarbital, diazepam, haloperidol and the vehicles produced responding on the green key. Similar results were obtained in group B. Finally, responses were reinforced on the green key after pentobarbital and on the red key after saline. Group B did not learn this discrimination. In group A, responding occurred on the red key after d-amphetamine, morphine, haloperidol and vehicles, in part after d-pentazocine, but not after pentobarbital, diazepam and PCP. These experiments show that drug stimuli can continue to exert stimulus control over behavior for long periods, even when training with several other drug stimuli intervenes between tests, and the experiments also show that through sequential training procedures multiple drugs can serve as discriminative stimuli for the same response, even when these drugs are from different phamacological classes.

Tumor necrosis factor-alpha augments pulmonary arterial transendothelial albumin flux in vitro

Tumor necrosis factor-alpha (TNF alpha) has been implicated as a mediator of pulmonary vascular endothelial injury. We studied the effect of human recombinant TNF alpha (rTNF alpha) on transfer of 14C-labeled bovine serum albumin (BSA) across cultured bovine pulmonary arterial endothelial cell monolayers. rTNF alpha induced a dose-, time-, and temperature-dependent increment in transendothelial [14C]BSA flux. Only after an incubation time of greater than or equal to 4 h did rTNF alpha significantly (P less than 0.005) increase transendothelial albumin flux. rTNF alpha exposure times as brief as 5 min induced significantly (P less than 0.005) increased albumin transfer at 6 h. Although this initial rTNF alpha-endothelial interaction was not temperature dependent, the subsequent barrier dysfunction could only be generated at 37 degrees C. The rTNF alpha-induced changes could not be ascribed to endothelial cell cytotoxicity and was not blocked by protein synthesis inhibition. The effects of rTNF alpha on endothelial permeability were reversible and not specific for albumin transfer. Therefore, rTNF alpha may influence the movement of macromolecules across the pulmonary vascular endothelial barrier.

Expression in Yersinia enterocolitica of K99 antigen gene of Escherichia coli

The expression of the determinant for the K99 antigen of Escherichia coli in Yersinia enterocolitica avirulent transconjugants D29(pFS239) and L15(pFS239) was confirmed by means of SDS-polyacrylamide gel electrophoresis, double immunodiffusion and Western blotting. The conditions for the expression of K99 antigen genes in Y. enterocolitica and in E. coli were compared. The K99 antigen protein expressed in Y. enterocolitica in the form of pili on the surface of the cells was discussed. This article offers the first description on the expression in Y. enterocolitica of gene from organism other than Yersinia spp.

Cloning in Yersinia enterocolitica of K99 antigen gene from Escherichia coli

A recombinant plasmid pFS239 containing the gene coding for K99 antigen of Escherichia coli and wide-host-range plasmid pKT230 has been cloned in E. coli C600. pFS239 has been transferred to Yersinia enterocolitica strains D29, L15 and L15 (pYV15) through triparental mating. In Y. enterocolitica transconjugants the expression of VW antigens and calcium dependence which represent the properties associated with the virulence plasmid of Y. enterocolitica remains unchanged.