This report highlights placental pathology that was probably the result of pathophysiological alteration of the maternal fetal unit during SARS. Further studies are required to delineate the relationship between severe maternal respiratory disease, placental pathology and pregnancy outcome.
The reaction of LiY [N i Pr 2 ] 4 with H 2 LCl () and BuLi in the molar ratio of 1:3:2 at -78 °C affords a yttrium complex supported by three anionic NHC ligands, L 3 Y (1). Reaction temperature has a great effect on the reaction outcome. The same reaction at room temperature yields a monoanionic NHC yttrium complex co-supported by a bridged bisphenoxo group, LY [(O-4,6di-t formed from the cleaVage of NHC.
In the present study, we aimed to investigate the association between gestational diabetes mellitus (GDM) and the oral microbial imbalance in the second trimester of pregnancy.Three hundred thirtyone women in the second trimester of pregnancy who underwent prenatal examinations at the Third Affiliated Hospital of Soochow University from February 2018 to August 2018 were included in this study. Personal parameters including the age, education level, and body mass index (BMI) at 28 weeks of gestation were recorded. Gestational diabetes mellitus (GDM) was diagnosed according to the Standards of Medical Care in Diabetes-2011 recommended by American Diabetes Association (ADA). After the significant difference of each parameter was erased by a propensity-score matched (PSM) analysis at a 1:1 ratio, the oral health conditions and the oral flora in pregnant women with GDM were compared with those in nondiabetic pregnant women.Our data demonstrated that 65 of the 331 pregnant women (19.6%) were diagnosed with GDM. Results from the matched data including 59 matched pairs of pregnant women showed that the gingival index (GI), plaque index (PI), tooth mobility degree (TMD), probing depth (PD), and bleeding on probing (BOP) of pregnant women with GDM were higher or more severe than those of nondiabetic pregnant women (P < .05). The detection rate of tuberculosis bacilli, Black-pigmented bacteria, and Capnocytophaga in pregnant women with GDM was higher than those in nondiabetic pregnant women (P = .000, P = .026, and P = .030, respectively). In addition, pregnant women with GDM had fewer oral streptococci (P = .000) and lactobacilli (P = .000) and more oral anaerobic bacteria (P = .000), tuberculosis bacilli (P = .000), Black-pigmented bacteria (P = .007), Capnocytophaga (P = .000), and actinomycetes (P = .000).The detection rate and the number of oral bacteria in pregnant women with GDM were higher than those in nondiabetic pregnant women in the second trimester of pregnancy.
Rare earth element and yttrium in hydrothermal fluids sampled from six high temperature vents and two diffuse flow sites on the Endeavour segment, Juan de Fuca Ridge by US-CHINA Joint Deep Dive Cruise in Aug. 2005 were analyzed by ICP-MS after being pre-concentrated by 20-fold. According to the species distributions calculated by GWB, the chondritenormalized REE patterns (REE CN ) of these fluids are characterized by LREE enrichment and positive Eu anomalies, which are mainly controlled by complexing with chloride. The (La/Yb) CN ratio does not correlate significantly with fluoride. Sulfate content are low in most high temperature fluids except in Gremlin vent fluids. Certain amounts of REE are complexed with sulfate that likely originates from oxidation of magmatic SO 2 and/or H 2 S in Gremlin. Sulfates, mostly come from seawater, are also responsible of large percentage of REE complexes in diffuse fluids.It is shown by the character of REY concentrations and the Y/Ho ratios that REE removed by Fe, Mn-oxyhydroxides is negligible in most of high temperature vent fluids. However, the Y/Ho ratios in Gremlin (Y/Ho = 160) and Faulty Towers (Y/Ho = 140) vent fluids are higher than that in other high temperature vent fluids, suggesting REE removal controlled by coprecipitation and scavenging. The negative Ce anomalies in diffuse fluids also result from the scavenging of mineral particles in the oxidizing conditions when mixing with seawater. Compared to ideal mixing fluids calculated by Mg content, two diffuse fluids display LREE-depleted patterns and enhanced positive Eu anomalies. Based on the REE characteristics of anhydrite, the REE distribution patterns of diffuse fluids are probably influenced largely by anhydrite precipitation under the seafloor at diffuse fluids sites. It is interesting to notice that the HREE CN pattern of Mothra vent fluids is similar to sediments but different from the sediment-starved hydrothermal fluids, suggesting they are likely remolded by the sediments in water-rock interaction zone and/or upflow zone nearby Mothra vent field. The provenance and character of these sediments bears further investigation.Keywords: hydrothermal fluids, rare earth element, Juan de Fuca Ridge, species abundance, Europium anomaly (Fouquet et al., 1993).Although the characteristics of REY in MOR systems have been well documented, the factors controlling the patterns and distributions of REY in hydrothermal fluids are still in debate. Klinkhammer et al. (1994a) systematically studied the REE of hydrothermal fluids from eight deep-sea hydrothermal areas and predicted that the REE distribution is dominated by crystochemical exchange with plagioclase phenocrysts. However, laboratory experiments indicated interstitial material and some secondary minerals are the main REE sources in the rock (Bach and Irber, 1998). Furthermore, coprecipitating with metal particles (German et al
The reaction of monomeric [(DIPPh)(2)nacnac]YbCl(2)(THF)(2) ((DIPPh)(2)nacnac = N,N-diisopropylphenyl-2,4-pentanediimineanion) with NaOAr (OAr = 2,6-diisopropylphenoxide) in THF afforded the mononuclear complexes [(DIPPh)(2)nacnac]Yb(OAr)Cl(THF) 1 and [(DIPPh)(2)nacnac]Yb(OAr)(2) 2 depending on the molar ratio of dichloride to sodium salt, while the same reaction with NaOAr' (OAr' = 2,6-dimethylphenoxide) in toluene yielded the binuclear complex [{(DIPPh)(2)nacnac}Yb(OAr')](2)(mu-Cl)(2) 3. Treatment of [(DIPPh)(2)nacnac]Yb(THF)(mu-Cl)(3)Yb(Cl)[(DIPPh)(2)nacnac] with NaOAr and NaOAr', respectively, in toluene yielded selectively the corresponding binuclear complexes {[(DIPPh)(2)nacnac]Yb(OAr)(mu-Cl)(3)Yb[(DIPPh)(2)nacnac](THF)} 4 and {[(DIPPh)(2)nacnac]Yb(OAr')(mu-Cl)(3)Yb[(DIPPh)(2)nacnac](THF)} 5 in high yields. All complexes were structurally characterized. Complex 2 was found to be a highly active initiator for both polymerizations of epsilon-caprolactone (epsilon-CL) and L-lactide. All monoaryloxide complexes can initiate the polymerization of epsilon-CL in a controlled manner giving polymers with narrow molecular weight distributions (M(w)/M(n) around 1.06) with relatively low activity relative to complex 2.
The lithium salt of the novel amido-phenoxo-functionalized NHC L (L = [3,5-t 1), was synthesized by the direct reaction of the salicylaldimino-functionalized imidazolium salt H 2 L 0 Br (L) with 2 equiv of Li n Bu and structurally characterized. Treatment of LnCl 3 with in situ formed 1 in a molar ratio of 1:1 at room temperature yielded the first cationic complexes(2), Lu (3), Er (4)) in good yields. Treatment of Li(THF)Ln(N i Pr 2 ) 4 with 2 equiv of H 2 L 0 Br at -78 5) and Yb ( 6)) in desired yields. Each central metal in cations [LnL 2 ] þ for 2-4 is coordinated by two L ligands, while the central metal in [L 0 2 Ln(THF)] þ for 5 and 6 is ligated by two ligands and one THF molecule. The structures of NHC lanthanide bromides have been found to depend on both the size of the metal and the ligand.
The Clarion and Clipperton Fracture Zones in the Eastern Pacific are well known as a manganese nodule belt, which developed since the late Oligocene. The slow growth rate of these marine ferromanganese nodules implies that they have potentially recorded long‐term environmental changes. To produce environmental records from these nodules, their chronology needs to be established first. In order to achieve this objective, many dating methods have been applied; however, due to relatively low‐resolution temporal constraint, high‐resolution environmental signals recorded in marine ferromanganese nodules have not been well documented yet. In this paper, we present a geochronological study based jointly on magnetic scanning and analyses of the authigenic beryllium isotopes (authigenic 10Be/9Be) and the cobalt (Co) flux of a marine ferromanganese nodule. Results lead to the following observations: (1) The growth of the studied nodule resulted from a combination of hydrogenetic and diagenetic processes, and (2) a total of 24 magnetozones is recognized for the studied nodule. Correlation to the geomagnetic polarity timescale suggests that chrons from C3n.2r to C1n were recorded in the nodule, implying that the growth of this nodule initiated ~4.70 Ma, which agrees well with the authigenic 10Be/9Be and Co chronometers. Furthermore, a consistent pattern of broad paleomagnetic field variations was observed between the nodule's magnetic signal and the ocean‐floor magnetic fields of the South Atlantic, confirming the validity of our growth model. Overall, our study highlights the potential of marine ferromanganese nodules from the Eastern Pacific as recorders of changes in Earth's magnetic field.
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