Group B Streptococcus (GBS) was the main causative organism of invasive infections in newborns due to vertical transmission from the colonized mothers. The study was undertaken to determine ...colonization rate, serotype distribution, genotypic characterization, antibiotic susceptibility profiles and molecular characteristics of erythromycin-resistant strains of GBS in pregnant women in Beijing, China. Vaginal–rectal swabs were collected from a total of 2850 pregnant women at 35–37 weeks of gestation, in which 7.1% were GBS positive. Serotypes III, Ia and V predominated. All isolates were penicillin susceptible, whereas the resistance rates for erythromycin and clindamycin were strikingly high.
Water resources and soil erosion are the most important environmental concerns on the Chinese Loess Plateau, where soil erosion and sediment yield are closely related to rainfall erosivity. Daily ...rainfall data from 60 meteorological stations were used to investigate the spatiotemporal variations in annual rainfall, annual erosive rainfall and annual rainfall erosivity on the Chinese Loess Plateau during the period 1956–2008. The annual rainfall, erosive rainfall and rainfall erosivity decreased over the past five decades, as determined by the Mann–Kendall test. A comparison of the annual averaged rainfall, erosive rainfall and rainfall erosivity from 1980 to 2008 with that from 1956 to 1979 revealed a remarkable spatial difference in the rainfall trends on the Loess Plateau. Regions of the plateau with major decreases in rainfall were primarily in the Hekouzhen-Longmen section of the middle Yellow River, especially in the Wuding River basin, the Fenhe basin and the northern-central Shanxi province, where the annual rainfall and erosive rainfall decreased by more than 10% and the annual rainfall erosivity decreased by more than 15%. The rainfall erosivity also decreased more than the annual rainfall. Because the annual rainfall has decreased significantly on the Chinese Loess Plateau over the past 50 years, it is important to better understand the ecological and hydrological processes affected by this climate change.
Data on river water quality from 42 monitoring stations in the Lower Mekong Basin obtained during the period 1972–1996 was used to relate solute fluxes with controlling factors such as chemical ...weathering processes. The total dissolved solid (TDS) concentration of the Lower Mekong varied from 53mg/L to 198mg/L, and the median (114mg/L) was compared to the world spatial median value (127mg/L). Total cationic exchange capacity (Tz+) ranged from 729 to 2607μmolc/L, and the mean (1572μmolc/L) was 1.4 times higher than the world discharge-weighted average. Calcium and bicarbonate dominated the annual ionic composition, accounting for ~70% of the solute load that equalled 41.2×109kg/y. TDS and major elements varied seasonally and in a predictable way with river runoff. The chemical weathering rate of 37.7t/(km2y), with respective carbonate and silicate weathering rates of 27.5t/(km2 y) (13.8mm/ky) and 10.2t/(km2 y) (3.8mm/ky), was 1.5 times higher than the global average. The CO2 consumption rate was estimated at 191×103molCO2/(km2y) for silicate weathering, and 286×103molCO2/(km2y) by carbonate weathering. In total, the Mekong basin consumed 228×109molCO2/y and 152×109molCO2/y by the combined weathering of carbonate and silicate, constituting 1.85% of the global CO2 consumption by carbonate weathering and 1.75% by silicates. This is marginally higher than its contribution to global water discharge ~1.3% and much higher than (more than three-fold) its contribution to world land surface area. Remarkable CO2 consumed by chemical weathering (380×109mol/y) was similar in magnitude to dissolved inorganic carbon as HCO3− (370×109mol/y) exported by the Mekong to the South China Sea. In this landscape, atmospheric CO2 consumption by rock chemical weathering represents an important carbon sink with runoff and physical erosion controlling chemical erosion.
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•TDS and major elements are inversely related to river runoff modeled using power law.•About 70% of the annual solute load is Ca2+ and HCO3−.•CO2 consumed by chemical weathering equates to HCO3− export.•High runoff and relief contribute to intense chemical weathering.•CO2-consumed rate by the Mekong (like other Himalayan rivers) exceeds global average.
The statistics of day‐to‐day tidal variability within 35‐day running mean windows is obtained from Michelson Interferometer for Global High‐Resolution Thermospheric Imaging (MIGHTI)/Ionospheric ...Connection Explorer (ICON) observations in the 90–107 km height region for the year 2020. Temperature standard deviations for 18 diurnal and semidiurnal tidal components, and for four quasi‐stationary planetary waves are presented, as function of latitude, altitude, and day‐of‐year. Our results show that the day‐to‐day variability (DTDV) can be as large as 70% of the monthly mean amplitudes, thus providing a significant source of variability for the ionospheric E‐region dynamo and hence for the F‐region plasma. We further validate our results with COSMIC‐2 ionospheric observations and present an approach to extend the MIGHTI/ICON results to all latitudes using Hough Mode Extension fitting, to produce global tidal fields and their statistical DTDV that are suitable as lower boundary conditions for nudging and ensemble modeling of TIE‐GCM. In the future, this will likely help to establish a data‐driven perspective of space weather variability caused by the tidal weather of the lower atmosphere.
Key Points
Statistics of the day‐to‐day variability (DTDV) of diurnal and semidiurnal tides in the ionospheric dynamo region is obtained from Michelson Interferometer for Global High‐Resolution Thermospheric Imaging/Ionospheric Connection Explorer
DTDV is validated with COSMIC‐2 ionospheric observations
Statistics is extended to all latitudes using Hough Mode Extensions
Summary
In this study, we aimed at investigating the impact of melatonin supplementation on semen parameters, hormonal profile and total antioxidant capacity after varicocelectomy. Infertile male ...patients who were diagnosed with varicocele and underwent subinguinal varicocelectomy were included in the study. After performing subinguinal varicocelectomy, the patients were randomised into two groups: 27 receiving melatonin for 3 months and 27 as the placebo‐controlled group receiving placebo for 3 months. The pre‐operative parameters of semen analyses, hormonal profile and seminal oxidative stress status of both groups were compared with those of post‐operative parameters. There were statistically significant improvements in post‐operative parameters of semen analyses (sperm concentration, motility and proportions of normally formed spermatozoa), peripheral blood inhibin B and total antioxidant capacity in melatonin group compared with placebo group. In conclusion, melatonin therapy adds extra benefit to varicecelectomy in terms of sperm parameters, peripheral blood inhibin B and total antioxidant capacity; however, further studies including large number of samples are needed to make a proper decision on melatonin supplementation after varicocelectomy.
Traumatic joint injuries often result in elevated proinflammatory cytokine (such as IL-1β) levels in the joint cavity, which can increase the catabolic activities of chondrocytes and damage ...cartilage. This study investigated the early genetic responses of healthy in situ chondrocytes under IL-1β attack with a focus on cell cycle and calcium signaling pathways. RNA sequencing analysis identified 2,232 significantly changed genes by IL-1β, with 1,259 upregulated and 973 downregulated genes. Catabolic genes related to ECM degeneration were promoted by IL-1β, consistent with our observations of matrix protein loss and mechanical property decrease during 24-day in vitro culture of cartilage explants. IL-1β altered the cell cycle (108 genes) and Rho GTPases signaling (72 genes) in chondrocytes, while chondrocyte phenotypic shift was observed with histology, cell volume measurement, and MTT assay. IL-1β inhibited the spontaneous calcium signaling in chondrocytes, a fundamental signaling event in chondrocyte metabolic activities. The expression of 24 genes from 6 calcium-signaling related pathways were changed by IL-1β exposure. This study provided a comprehensive list of differentially expressed genes of healthy in situ chondrocytes in response to IL-1β attack, which represents a useful reference to verify and guide future cartilage studies related to the acute inflammation after joint trauma.
Nanostructured materials provide a promising platform for early cancer detection and treatment. Here we highlight recent advances in the synthesis and use of Au nanocages for such biomedical ...applications. Gold nanocages represent a novel class of nanostructures, which can be prepared via a remarkably simple route based on the galvanic replacement reaction between Ag nanocubes and HAuCl4. The Au nanocages have a tunable surface plasmon resonance peak that extends into the near‐infrared, where the optical attenuation caused by blood and soft tissue is essentially negligible. They are also biocompatible and present a well‐established surface for easy functionalization. We have tailored the scattering and absorption cross‐sections of Au nanocages for use in optical coherence tomography and photothermal treatment, respectively. Our preliminary studies show greatly improved spectroscopic image contrast for tissue phantoms containing Au nanocages. Our most recent results also demonstrate the photothermal destruction of breast cancer cells in vitro by using immuno‐targeted Au nanocages as an effective photo‐thermal transducer. These experiments suggest that Au nanocages may be a new class of nanometer‐sized agents for cancer diagnosis and therapy.
Gold nanocages represent a novel class of biocompatible nanostructures, with potential cancer diagnostic and therapy properties intrinsic to their surface plasmon resonance (SPR). They are prepared by the galvanic replacement reaction between Ag nanocubes and HAuCl4 solution, and their SPR peak position can be precisely tuned into the near‐infrared. Recent advances in the use of Au nanocages as optical contrast enhancement and photothermal therapy agents are discussed.
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