Analyses of rare earth and trace element concentrations of native sulfur samples from the Kueishantao hydrothermal field were performed at the Seafloor Hydrothermal Activity Laboratory of the Key ...Laboratory of Marine Geology and Environment,Institute of Oceanology,Chinese Academy of Sciences.Using an Elan DRC II ICP-MS,and combining the sulfur isotopic compositions of native sulfur samples,we studied the sources and formation of a native sulfur chimney.The results show,when comparing them with native sulfur from crater lakes and other volcanic areas,that the native sulfur content of this chimney is very high (99.96%),the rare earth element (REE) and trace element constituents of the chimney are very low (ΣREE<21×10-9),and the chondrite-normalized REE patterns of the native sulfur samples are similar to those of the Kueishantao andesite,implying that the interaction of subseafloor fluid-andesite at the Kueishantao hydrothermal field was of short duration.The sulfur isotopic compositions of the native sulfur samples reveal that the sulfur of the chimney,from H2S and SO2,originated by magmatic degassing and that the REEs and trace elements are mostly from the Kueishantao andesite and partly from seawater.Combining these results with an analysis of the thermodynamics,it is clear that from the relatively low temperature (<116℃),the oxygenated and acidic environment is favorable for formation of this native sulfur chimney in the Kueishantao hydrothermal field.
Fast radio bursts (FRBs) are bright millisecond radio bursts at cosmological distances. Only three FRBs have exhibited extreme activities, such as achieving a peak event rate \(\gtrsim 100\) ...hr\(^{-1}\) or being persistently active. Only these three among \(\sim 50\) known repeating FRBs have circular polarization. We observed the FRB 20220912A with the Robert C. Byrd Green Bank Telescope (GBT) at L-band on 24 October 2022 and detected 128 bursts in 1.4 hours, corresponding to a burst rate of about 90 hr\(^{-1}\), which is the highest yet for FRBs observed by the GBT and makes it the fourth extremely active FRB. The median energy of the bursts is \(4.0\times10^{37}\) erg, close to the characteristic energy of FRB 20121102A. The average rotation measure (RM) was \(-\)0.4 rad m\(^{-2}\) with unnoticeable intraday RM change, indicating a likely clean environment, in contrast to the other three extremely active repeating FRBs. Most bursts have nearly 100% linear polarization. Approximately 56% of the bright bursts have circular polarization, the highest such fraction among all FRBs. A downward drift in frequency and polarization angle swings were found in our sample. The discovery and characterization of FRB 20220912A support the view that the downward drift in frequency, polarization angle swings, and circular polarization are intrinsic to radiation physics, which may be shared by active repeaters regardless of the environments.
Summary
The Sonic hedgehog (SHH) signaling pathway plays a pivotal role in neurogenesis and brain damage repair. Our previous work demonstrated that the SHH signaling pathway was involved in the ...neuroprotection of cortical neurons against oxidative stress. The present study was aimed to further examine the underlying mechanism. The cortical neurons were obtained from one-day old Sprague-Dawley neonate rats. Hydrogen peroxide (H
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, 100 μmol/L) was used to treat neurons for 24 h to induce oxidative stress. Exogenous SHH (3 μg/mL) was employed to activate the SHH pathway, and cyclopamine (20 μmol/L), a specific SHH signal inhibitor, to block SHH pathway. LY294002 (20 μmol/L) were used to pre-treat the neurons 30 min before H
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treatment and selectively inhibit the phosphatidylinositol 3-kinase (PI3K)/Akt pathway. The cell viability was measured by MTT and apoptosis rate by flow cytometry analysis. The expression of p38, p-p38, ERK, p-ERK, Akt, p-Akt, Bcl-2, and Bax in neurons was detected by immunoblotting. The results showed that as compared with H
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treatment, exogenous SHH could increase the expression of p-Akt by 20% and decrease the expression of p-ERK by 33%. SHH exerted no significant effect on p38 mitogen-activated protein kinase (p38 MAPK) pathway. Blockade of PI3K/Akt pathway by LY294002 decreased the cell viability by 17% and increased the cell apoptosis rate by 2-fold. LY294002 treatment could up-regulate the expression of the pro-apoptotic gene Bax by 12% and down-regulate the expression of the anti-apoptotic gene Bcl-2 by 54%. In conclusion, SHH pathway may activate PI3K/Akt pathway and inhibit the activation of the ERK pathway in neurons under oxidative stress. The PI3K/Akt pathway plays a key role in the neuroprotection of SHH. SHH/PI3K/Bcl-2 pathway may be implicated in the protection of neurons against H
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-induced apoptosis.
To analyze factors influencing the choice of atrial septal occluder (ASO) for transcatheter closure of patients with secundum atrial septal defect (ASD).
A total of 1114 ASD patients 388 males, aged ...from 2 to 75 years, mean age (26.3 +/- 17.0) years were enrolled. Patients were divided to adult (> 14 years, mean 34.4 years, n = 779) and child (< or = 14 years, mean 7.3 years, n = 335) groups. ASD size in different ultrasound cross-sections was determined by transthoracic echocardiography (TTE). ASO size was chosen on the basis of the maximum diameter of the defect (MD). Defect-shapes and rim lengths of ASD, the difference choice of ASO in the two groups were compared.
MD of the defects ranged from 5 to 40 mm mean (19.7 +/- 7.8) mm. ASD was successfully occluded in 1085 out of 1114 patients (97.4%). Occluder size ranged from 6 to 46 mm mean (25.8 +/- 8.9) mm and the difference between occluder size and MD ranged from 2 to 10 mm mean (6.1 +/- 3.4) mm, ASO/MD ratio 1.3:1. Though the diameter of the defec
To investigate the effect of L-NAME on nitric oxide and gastrointestinal motility alterations in cirrhotic rats.
Rats with cirrhosis induced by carbon tetrachloride were randomly divided into two ...groups, one n =13 receiving 0.5mg.kg(-1) per day of N(G)-nitro-L-arginine methyl ester (L-NAME), a nitric oxide synthase inhibitor, for 10 days, whereas the other group (n =13) and control (n =10) rats were administrated the same volume of 9g.L(-1) saline. Half gastric emptying time and 2h residual rate were measured by SPECT, using (99m)Tc-DTPA-labeled barium sulfate as test meal. Gastrointestinal transition time was recorded simultaneously. Serum concentration of nitric oxide (NO) was determined by the kinetic cadmium reduction and colorimetric methods. Immunohistochemical SABC method was used to observe the expression and distribution of three types of nitric oxide synthase (NOS) isoforms in the rat gastrointestinal tract. Western blot was used to detect expression of gastrointestinal NOS isoforms.
Half gastric emptying time and trans-gastrointestinal time were significantly prolonged(124.0 +/- 26.4 min; 33.7 +/- 8.9 min; 72.1 +/- 15.3 min; P<0.01), (12.4 +/- 0.5h; 9.5 +/- 0.3h; 8.2 +/- 0.8h; P<0.01), 2h residual rate was raised in cirrhotic rats than in controls and cirrhotic rats treated with L-NAME (54.9 +/- 7.6%,13.7 +/- 3.2%, 34.9 +/- 10.3%, P<0.01). Serum concentration of NO was significantly increased in cirrhotic rats than in the other groups (8.20 +/- 2.48) micromol.L(-1), (5.94 +/-1.07) micromol.L(-1) and control (5.66 +/- 1.60 micromol.L(-1), P<0.01. NOS staining intensities which were mainly located in the gastrointestinal tissues were markedly lower in cirrhotic rats than in the controls and cirrhotic rats after treated with L-NAME.
Gastrointestinal motility was remarkably inhibited in cirrhotic rats, which could be alleviated by L-NAME. Nitric oxide may play an important role in the inhibition of gastrointestinal motility in cirrhotic rats.
To investigate high risk human papillomavirus (HR-HPV) prevalence among married women in Beijing and to study the high risk factors.
During March 2007 to September 2008, a total of 6185 married women ...sampled from 137 communities in 12 districts were screened by HR-HPV DNA test and cytological test. The interview was carried out with unified questionnaires. The database was set up and twice entered in EpiData 3.0. After checked up, the data were analyzed in SPSS 15.0.
(1) The HR-HPV infection rate was 9.89%. The HR-HPV infection rate of the city zone, the suburb and the exurb were 9.34%, 10.51% and 9.51% (P > 0.05). The HR-HPV infection rate of the native and the outlander were 9.53%, 11.30% (P < 0.05). (2) The age distribution of HR-HPV infection was that the rate was around 10% among 25 to 44 age groups, which was the highest (11.21%) in 30 to 34 age group; then the rate was descended as the age raising, the rate of 50 to 54 age group was the lowest (7.78%). (3) Multiple logistic regression showed that the r
In our previous study, we found that the sonic hedgehog (Shh) signaling pathway is activated in neurons under oxidative stress and plays a neuro-protective role Dai RL, et al. (2011) Neurochem Res ...36:67-75; we are led to postulate that the Shh might be released by astrocytes, thereby protecting neurons against oxidant injury. In primary cultured astrocytes of rats, we found that treatment with 100 μM H₂O₂ for 24 h induced a significant increase in the mRNA and protein levels of Shh, Patched1, and Gli-1, and the increase was substantially greater in astrocytes than in neurons. In the coculture systems of astrocytes and neurons under the H₂O₂ treatment, blocking the Shh signaling pathway with 5E1 (an antibody against the N-terminal domain of Shh) could block the neuroprotective activity of astrocytes on cocultured neurons. In this study, we found that treatment with H₂O₂ (100-800 μM) for 24 h caused cell death of astrocytes in a concentration-dependent manner. MTT reduction and Trypan Blue exclusion assay showed that exogenous Shh increased survival rate of the H₂O₂-treated astrocytes, whereas pretreatment with cyclopamine (a specific inhibitor of the Shh signaling pathway) or 5E1 decreased the survival rate of the H₂O₂-treated astrocytes. Shh also inhibited H₂O₂-induced apoptosis of astrocytes, and this effect could be partially reversed by cyclopamine. We also found that Shh promoted the phosphorylation of AKT, but had no significant effect on p38 or extracellular signal regulated kinases 1 and 2 (ERK 1/2) in H₂O₂-treated astrocytes. Blocking Shh or phosphoinositide 3-kinases (PI3-K)/AKT signaling pathway with cyclopamine or LY294002 decreased the survival rate of astrocytes, induced cell apoptosis, upregulated the expression of Bax, and downregulated the expression of Bcl-2. We are led to conclude that the oxidative stress induces astrocytes to secrete endogenous Shh and exogenous administration of Shh might protect the astrocytes from oxidative stress by activating PI3-K/AKT/Bcl-2 pathway.
The geochemical and U-series isotopic characteristics of hydrothermal sulfide samples from the Jade site (127°04.5′E, 27°15′N, water depth 1300-1450 m) at Jade site in the Okinawa Trough were ...analyzed. In the hydrothermal sulfide samples bearing sulfate (samples HOK1 and HOK2), the LREEs are relatively enriched. All the hydrothermal sulfide samples except HOK1 belong to Zn-rich hydrothermal sulfide. In comparison with Zn-rich hydrothermal sulfides from other fields, the contents of Zn, Pb, Ag, Cd, Au and Hg are higher, the contents of Fe, Al, Cr, Co, Ni, Sr, Te, Cs, Ti and U lower, and the 210Pb radioactivity ratios and 210Pb/Pb ratios very low. In the hydrothermal sulfide mainly composed of sphalerite, the correlations between rare elements Hf and U, and Hf and Mn as well as that between dispersive elements Ga and Zn, are strongly positive; also the contents of Au and Ag are related to Fe-sulfide, because the low temperature promotes enrichment of Au and Ag. Meanwhile, the positive correlations between Fe and Bi and between Zn and Cd are not affected by the change of mineral assemblage. Based on the 210Pb/Pb ratios of hydrothermal sulfide samples (3.99×10-5-5.42×10?5), their U isotopic composition (238U content 1.15-2.53 ppm, 238U activity 1.07-1.87 dpm/g, 234U activity 1.15-2.09 dpm/g and 234U/238U ratio 1.07-1.14) and their 232Th and 230Th contents are at base level, and the chronological age of hydrothermal sulfide at Jade site in the Okinawa Trough is between 200 and 2000 yr.
To analyze the sequence of GJB2 gene in nonsyndromic hearing impairment (NSHI) patients in China.
Peripheral blood samples were obtained from 1190 NSHI patients randomly selected from the Deaf and ...Mute Schools of Beijing, Hebei, Heilongjiang, Jilin, Inner Mongolia, Shanxi, Henan, Hubei, Shaanxi, Gansu, Ningxia, Qinghai, Anhui, Jiangsu, Shanghai, Fujian, Guangdong, and Guangxi, and 301 children with normal hearing level used as controls. Genomic DNA was extracted by extraction kits to undergo polymerase chain reaction and sequencing so as to detect the mutations of GJB2 gene.
Sixteen pathogenic mutations of GJB2 gene were found, the most common of which included 235delC, 299-300delAT, and 176del16bp. 250 patients (21.05%) carried definite GJB2 mutations, 245 of which (98%) carried at least one of these 3 common mutations. 222 of the 250 patients (88.80%) carried the mutation 235delC with a detection rate of 18.66%. 62 of the 250 patients (24.80%) carried the mutation 299-300delAT with a detection rate of 5.21%
To evaluate the impact of hypertension on the clinical outcome of COVID-19 patients aged 60 years old and older.Methods:This single-center retrospective cohort study enrolled consecutive COVID-19 ...patients aged 60 years old and older,who were admitted to Liyuan Hospital from January 1,2020 to April 25,2020.All included patients were divided into two groups:hypertension and nonhypertension group.The baseline demographic characteristics,laboratory test results,chest computed tomography(CT)images and clinical outcomes were collected and analyzed.The prognostic value of hypertension was determined using binary logistic regression.Results:Among the 232 patients included in the analysis,105(45.3％)patients had comorbid hypertension.Compared to the nonhypertension group,patients in the hypertension group had higher neutrophil-to-lymphocyte ratios,red cell distribution widths,lactate dehydrogenase,high-sensitivity C-reactive protein,D-dimer and severity of lung lesion,and lower lymphocyte counts(all P＜0.05).Furthermore,the hypertension group had a higher proportion of intensive care unit admissions24(22.9％)vs.14(11.0％),P=0.02)and deaths16(15.2％)vs.3(2.4％),P＜0.001and a significantly lower probability of survival(P＜0.001)than the nonhypertension group.Hypertension(OR:4.540,95％CI:1.203-17.129,P=0.026)was independently correlated with all-cause in-hospital death in elderly patients with COVID-19.Conclusion:The elderly COVID-19 patients with hypertension tend to have worse conditions at baseline than those without hypertension.Hypertension may be an independent prognostic factor of poor clinical outcome in elderly COVID-19 patients.
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