This synthesis addresses the vulnerability of the North American high‐latitude soil organic carbon (SOC) pool to climate change. Disturbances caused by climate warming in arctic, subarctic, and ...boreal environments can result in significant redistribution of C among major reservoirs with potential global impacts. We divide the current northern high‐latitude SOC pools into (1) near‐surface soils where SOC is affected by seasonal freeze‐thaw processes and changes in moisture status, and (2) deeper permafrost and peatland strata down to several tens of meters depth where SOC is usually not affected by short‐term changes. We address key factors (permafrost, vegetation, hydrology, paleoenvironmental history) and processes (C input, storage, decomposition, and output) responsible for the formation of the large high‐latitude SOC pool in North America and highlight how climate‐related disturbances could alter this pool's character and size. Press disturbances of relatively slow but persistent nature such as top‐down thawing of permafrost, and changes in hydrology, microbiological communities, pedological processes, and vegetation types, as well as pulse disturbances of relatively rapid and local nature such as wildfires and thermokarst, could substantially impact SOC stocks. Ongoing climate warming in the North American high‐latitude region could result in crossing environmental thresholds, thereby accelerating press disturbances and increasingly triggering pulse disturbances and eventually affecting the C source/sink net character of northern high‐latitude soils. Finally, we assess postdisturbance feedbacks, models, and predictions for the northern high‐latitude SOC pool, and discuss data and research gaps to be addressed by future research.
Key Points
SOC in northern high latitudes is highly vulnerable to disturbances
Disturbances are an important component of the northern soil C cycle
Soils in northern high latitudes could loose their long‐term C sink character
Four new chalcones (1, 10, 13, and 14), a new flavanone, (9), a new amide (8), and 19 known compounds were acquired from Melodorum siamensis. The structures were established by NMR and MS data ...analyses. Compounds 1 (er 1.4:1) and 2 (er 1.1:1) were scalemic and were resolved to yield (−)-1 and (+)-1 and (−)-2 and (+)-2, respectively. The absolute configurations of these compounds were determined from experimental and calculated ECD data. The structures and configurations of (−)-2 and (+)-8 were identified by single-crystal X-ray diffraction analysis. Compound 11 showed nuclear factor-κB inhibitory effects (IC50 = 9 μM) in a pancreatic β cell line (MIN-6 cells).
•Heyrovskyite - Pb6Bi2S9 (H- LBS) compound was synthesized by chemical bath deposition.•Orthorhombic Pb6Bi2S9 phase prevailed in annealed films.•The optical absorption edge ranged from 1.31 to ...1.62 eV.•A H- LBS/PbS diode generated VOC = 285 mV and JSC = 13.3 mA/cm2.
In this work, we report the procedure for the synthesis by chemical bath deposition of Heyrovskyite - Pb6Bi2S9 (H- LBS) thin films as a new emerging material. Homogeneous thin films are obtained, with a thickness from 95 to 130 nm. X-ray diffraction shows that deposited films are amorphous, and crystallize to the orthorhombic Pb6Bi2S9 phase when annealed in air at 150 °C. The deposited material has direct optical energy gap (Eg)from 1.31 to 1.62 eV. A heterojunction formed by H- LBS/PbS shows diode behavior with the generation of open circuit voltage (VOC) of 285 mV, short circuit current density (JSC) of 13.3 mA/cm2 and power conversion efficiency (PCE) of 0.98%, evidencing the feasible application of H- LBS thin films as absorbers in solar cells.
The mechanical properties of Ti alloys are changed significantly with the addition of interstitial elements, such as oxygen. Because oxygen is a strong stabilizer of the α phase and has an effect on ...hardening in a solid solution, it has aroused great interest in the biomedical area. In this paper, Ti-Zr alloys were subjected to a doping process with small amounts of oxygen. The influence of interstitial oxygen in the structure, microstructure and some selected mechanical properties of interest for use as biomaterial and biocompatibility of the alloys were analyzed. The results showed that in the range of 0.02 wt% to 0.04 wt%, oxygen has no influence on the structure, microstructure or biocompatibility of the studied alloys, but causes hardening of the alloys, increasing the values of the microhardness and causing variation in the elasticity modulus values.
Aims
Several clinical trials have confirmed the therapeutic benefit of imipenem for treatment of lung infections. There is however no knowledge of the penetration of imipenem into the lung epithelial ...lining fluid (ELF), the site of action relevant for lung infections. Furthermore, although the plasma pharmacokinetics (PK) of imipenem has been widely studied, most studies have been based on selected patient groups. The aim of this analysis was to characterize imipenem plasma PK across populations and to quantify imipenem ELF penetration.
Methods
A population model for imipenem plasma PK was developed using data obtained from healthy volunteers, elderly subjects and subjects with renal impairment, in order to identify predictors for inter‐individual variability (IIV) of imipenem PK. Subsequently, a clinical study which measured plasma and ELF concentrations of imipenem was included in order to quantify lung penetration.
Results
A two compartmental model best described the plasma PK of imipenem. Creatinine clearance and body weight were included as subject characteristics predictive for IIV on clearance. Typical estimates for clearance, central and peripheral volume, and inter‐compartmental clearance were 11.5 l h–1, 9.37 l, 6.41 l, 13.7 l h–1, respectively (relative standard error (RSE) <8%). The distribution of imipenem into ELF was described using a time‐independent penetration coefficient of 0.44 (RSE 14%).
Conclusion
The identified lung penetration coefficient confirms the clinical relevance of imipenem for treatment of lung infections, while the population PK model provided insights into predictors of IIV for imipenem PK and may be of relevance to support dose optimization in various subject groups.
Background:
Pregnancy in women with autoimmune rheumatic diseases (ARD) is associated with an increase in the risk of adverse perinatal outcomes and birth defects. Many factors have been attributed ...to these including medication employed and maternal autoantibodies. The national prevalence of congenital anomalies in newborns in Mexico is estimated to be 73.9 per 10,000 births but the rate of these in Mexican women with ARD is unknown.
Objectives:
This study aims to describe the frequency of adverse perinatal outcomes and congenital defects in Mexican women with ARD.
Methods:
We performed a descriptive and prospective study that included all pregnant patients with ARDs from the clinic of pregnancy and rheumatic diseases in the University Hospital “Dr. José Eleuterio González” who gave birth between February 2019 to November 2020. Demographic information, pregnancy outcome, and congenital defects were prospectively evaluated. Congenital defects were clinically confirmed by a clinical geneticist.
Results:
A total of 40 women were taken in the final analyses. The ARD diagnosis is shown in graphic 1. Rheumatoid arthritis was the most frequent diagnosis that had an adverse perinatal outcome with 4 (40%) and congenital defects in 2 (40%). No complications or birth defects were reported in 25 (62.5%). The adverse perinatal outcome was reported in 10 (25%) women and congenital defects in 5 (12.5%). The most frequent adverse perinatal outcomes were preterm birth 6 (15%) and the second most frequent miscarriage 3 (7.5%) (Table 1 below).
Conclusion:
We found a high frequency (12.5%) of adverse perinatal outcomes and congenital defects in Mexican women with ARD. Multidisciplinary groups and clinics are needed to adequately serve this complex population and reduce morbidity and mortality. A multidisciplinary approach before, during, and after pregnancy in patients with ARD may improve morbidity and mortality.
References:
1Vinet, E., Bernatsky, S. (2017). Outcomes in Children Born to Women with Rheumatic Diseases. Rheum Dis Clin N Am.
http://dx.doi.org/10.1016/j.rdc.2016.12.006
.
2Krishnan AN, Sable CA, Donofrio MT.(2008). Spectrum of fetal echocardiographic findings in fetuses of women with clinical or serologic evidence of systemic lupus erythematosus. J Matern Fetal Neonatal Med. 21(11):776–82.
3NAVARRETE HERNANDEZ, Eduardo et al. Prevalencia de malformaciones congénitas registradas en el certificado de nacimiento y de muerte fetal: México, 2009-2010.
Bol. Med. Hosp. Infant. Mex.
online. 2013, vol.70, n.6, pp.499-505.
Graphic 1.
Percentage of adverse perinatal outcomes and congenital defects due to rheumatic disease.
Table 1.
Frequency and percentages of adverse perinatal outcomes and congenital defects.
Adverse perinatal outcome (n=10) 25%
Congenital defects (n=5) 12.5%
Preterm birth
6 (15%)
-
Miscarriage
3 (7.5%)
-
Stillbirth
1 (2.5%)
-
Congenital heart disease*
-
1 (2.5%)
Congenital cardiac block with pacemaker placement
-
1 (2.5%)
Krabbe´s disease
-
1 (2.5%)
Preauricular appendix
-
1 (2.5%)
Diabetic fetopathy
-
1 (2.5%)
*Tetralogy of Fallot
Disclosure of Interests:
None declared
Gamma-ray and neutron spectra from the
18
O
+
76
Se
reaction at 15.3 MeV/u were measured with the EDEN array of liquid scintillators at the LNS. The results were compared to GEANT Hadrontherapy ...physics list simulations in order to assess the reliability of this model for the development of the NUMEN project. A good agreement with the shape of the experimental gamma-ray spectra and a reasonable agreement with the total count rates were obtained. The gamma spectra originated from the nuclear reactions were selected by time coincidence with the Superconducting Cyclotron radio-frequency reference signal. The random coincidence background rate was appropriately described only when the Faraday Cup, the material and geometry of the experimental hall and its contents were included in the simulation with sufficient detail. The information on the radiation spectra is important for the adequate development of the project of the detector arrays and electronic equipment for the advanced phase of NUMEN. Since orders of magnitude larger beam intensities are planned for this phase, the random coincidence rate is also of significant importance, particularly for the performance of the G-NUMEN gamma calorimeter array.
Neonatal hypoxic-ischemic injury of the brain and resultant encephalopathy (HIE) leads to major developmental impairments by school age. Conventional/anatomical MRI often fails to detect hippocampal ...injury in mild cases. We hypothesize that diffusion tensor imaging (DTI) has greater sensitivity for identifying subtle hippocampal injury.
We retrospectively analyzed DTI data collected from a cohort of neonates with HIE and controls. Conventional MRI sequences were classified qualitatively according to severity using a modified Barkovich scale. Using multivariate linear regression, we compared hippocampal DTI scalars of HIE patients and controls. Spearman correlation was used to test the association of DTI scalars in the hippocampal and thalamic regions. A multiple regression analysis tested the association of the DTI scalars with short-term outcomes.
Fifty-five neonates with HIE (42% males) and 13 controls (54% males) were included. Hippocampal DTI scalars were similar between HIE and control groups, even when restricting the HIE group to those with moderate-to-severe injury (8 subjects). DTI scalars of the thalamus were significantly lower in the moderate-to-severely affected patients compared to controls (right fractional anisotropy FA .148 vs. .182, P = .01; left FA .147 vs. .181, P = .03). Hippocampal and thalamic DTI scalars were correlated (P < .001). Hippocampal DTI scalars were not associated with short-term outcomes.
Quantitative DTI analysis of the hippocampus in neonates following HIE is a feasible technique to examine neuronal injury. Although DTI scalars were useful in identifying thalamic injury in our cohort, hippocampal DTI analysis did not provide additional information regarding hippocampal injury following HIE.
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