Effects of glutamate on distortion–product otoacoustic emissions and auditory brainstem responses in guinea pigs

AbstractObjectivesTo investigate changes in evoked potentials and structure of the guinea pig cochleae during whole cochlear perfusion with glutamate.MethodsCM, CAP, DPOAE, and ABR were recorded as indicators of cochlear functions during whole cochlear perfusion. The morphology of the cochlea was studied via transmission electron microscopy.ResultsThere were no significant changes in DPOAE amplitude before and after glutamate perfusion. CM I/O function remained nonlinear during perfusion. ABR latencies were delayed following glutamate perfusion. The average CAP threshold was elevated 35 dB SPL following glutamate perfusion.. The OHCs appeared normal, but the IHCs and afferent dendrites showed cytoplasmic blebs after glutamate perfusion.ConclusionsWhile being a primary amino acid neurotransmitter at the synapses between hair cells and spiral ganglion neurons, excessive glutamate is neurotoxic and can destroy IHCs and spiral ganglion neurons. The technique used in this study can also be used to build an animal model of auditory neuropathy

Structural patterns of city-level CO2 emissions in Northwest China

In Northwest China, quantifying city-level CO2 emissions is fundamental to CO2 alleviation but encounters difficulties in data availability and quality. Further, structuring city-level emissions could be conductive to CO2 reduction. This study applies a practical methodology to 16 northwestern Chinese cities to grasp their historical trajectories of CO2 emissions. Then, structuring CO2 emissions is explored in terms of industrial structure, energy mix and urban-rural disparities for 8 northwestern Chinese cities. Results show that: (1) for 16 cities (2010–2015), capital and industrial cities generated most emissions. Meanwhile, CO2 emissions were mostly incompatible with CO2 intensity, but consistent with CO2 per capita; (2) for 8 cities (2006–2015), energy producing sectors, heavy manufacturing sectors, and coal remained major drivers of emissions. Then, the interconnection between industrial structure and energy mix exerted temporally varying impacts on emissions from energy producing sectors and heavy manufacturing sectors. Besides, urban gas consumption and rural coal use continued affecting most of household consumption emissions and household consumption emissions per capita. Moreover, the interplay between emissions and population was changed when emissions by energy type were decomposed among urban and rural households; and (3) uncertainty results averagely fall in the range of −39% to 6%. Finally, implications for CO2 reduction and future work are proposed

A Study of the Merger History of the Galaxy Group HCG 62 Based on X-Ray Observations and SPH Simulations

We choose the bright compact group HCG 62, which was found to exhibit both excess X-ray emission and high Fe abundance to the southwest of its core, as an example to study the impact of mergers on chemical enrichment in the intragroup medium. We first reanalyze the high-quality Chandra and XMM-Newton archive data to search for the evidence for additional SN II yields, which is expected as a direct result of the possible merger-induced starburst. We reveal that, similar to the Fe abundance, the Mg abundance also shows a high value in both the innermost region and the southwest substructure, forming a high-abundance plateau, meanwhile all the SN Ia and SN II yields show rather flat distributions in $>0.1r_{200}$ in favor of an early enrichment. Then we carry out a series of idealized numerical simulations to model the collision of two initially isolated galaxy groups by using the TreePM-SPH GADGET-3 code. We find that the observed X-ray emission and metal distributions, as well as the relative positions of the two bright central galaxies with reference to the X-ray peak, can be well reproduced in a major merger with a mass ratio of 3 when the merger-induced starburst is assumed. The `best-match' snapshot is pinpointed after the third pericentric passage when the southwest substructure is formed due to gas sloshing. By following the evolution of the simulated merging system, we conclude that the effects of such a major merger on chemical enrichment are mostly restricted within the core region when the final relaxed state is reached.Comment: Accepted for publication in the Astrophysical Journa

Adaptive CO2 emissions mitigation strategies of global oil refineries in all age groups

Continuous expansion of fossil fuel-based energy infrastructure can be one of the key obstacles in delivering the Paris Agreement goals. The oil refinery is the world's third-largest stationary emitter of greenhouse gases (GHGs), but the historical mapping of the regional-specific refining industry, their CO2 emission patterns, and mitigation potentials remain understudied. This study develops a plant-level, technical-specific, and time-series global refinery CO2 emission inventory, covering 1,056 refineries from 2000 to 2018. The CO2 emissions of the refinery industry were about 1.3 gigatonnes (Gt) in 2018, representing 4% of the total. If current technical specifications continue, the global refineries will cumulatively emit 16.5 Gt of CO2 during 2020–2030. The refineries vary in operation age, refining configuration structure, and geographical location, leading to the demand for specific mitigation strategies, such as improving refinery efficiency and upgrading heavy oil processing technologies, which could potentially reduce global cumulative emissions by 10% during 2020–2030

Kazakhstan’s CO2 emissions in the post-Kyoto Protocol era:Production- and consumption-based analysis

The first commitment period of the Kyoto Protocol came to an end in 2012 and more developing countries began to participate in the new phase of world carbon emission reduction. Kazakhstan is an important energy export country and a pivot of the “Belt and Road Initiative” (BRI). Despite its emissions are relatively small compared with huge emitters such as China and the US, Kazakhstan also faces great pressure in terms of CO2 emission reduction and green development. Accurately accounting CO2 emissions in Kazakhstan from both production and consumption perspectives is the first step for further emissions control actions. This paper constructs production-based CO2 emission inventories for Kazakhstan from 2012 to 2016, and then further analyses the demand-driven emissions within the domestic market and international trade (exports and imports) using environmentally extended input-output analysis. The production-based inventory includes 43 energy products and 30 sectors to provide detailed data for CO2 emissions in Kazakhstan. The consumption-based accounting results showed that certain sectors like construction drive more emissions and that the fuel consumption in different sectors varies. Furthermore, Russia and China are major consumers of Kazakhstan's energy and associated emissions, with the construction sector playing the most important role in it. The results suggested that both technology and policy actions should be taken into account to reduce CO2 emissions and that the BRI is also a good chance for Kazakhstan to develop a “Green Economy”

Outsourced carbon mitigation efforts of Chinese cities from 2012 to 2017

Outsourced carbon mitigation between cities means that some cities benefit from the carbon mitigation efforts of other cities more than their own. This problem conceals the recognition of cities’ mitigation contributions. Here we quantify local and outsourced carbon mitigation levels from 2012 to 2017 and identified ‘outsourced mitigation beneficiaries’ relying on outsourced efforts more than their own among 309 Chinese cities by using a city-level input–output model. It found that the share of outsourced emissions rose from 78.6% to 81.9% during this period. In particular, 240 cities (77.7%) were outsourced mitigation beneficiaries, of which 65 were strong beneficiaries (their local carbon emissions still grew) and 175 cities were weak beneficiaries (with larger outsourced mitigation efforts than local mitigation efforts). Strong beneficiaries were often industrializing cities with more agriculture and light manufacturing, focusing on local economic growth. In contrast, weak beneficiaries were mainly at the downstream of supply chains with services and high-tech manufacturing, which have stronger connections with upstream heavy industry cities. The findings suggest the need for policies to manage outsourced mitigation of supply chains and encourage transformation, improving the fair acknowledgment of cities’ carbon mitigation efforts

Ising Superconductivity and Quantum Phase Transition in Macro-Size Monolayer NbSe2

Two-dimensional (2D) transition metal dichalcogenides (TMDs) have a range of unique physics properties and could be used in the development of electronics, photonics, spintronics and quantum computing devices. The mechanical exfoliation technique of micro-size TMD flakes has attracted particular interest due to its simplicity and cost effectiveness. However, for most applications, large area and high quality films are preferred. Furthermore, when the thickness of crystalline films is down to the 2D limit (monolayer), exotic properties can be expected due to the quantum confinement and symmetry breaking. In this paper, we have successfully prepared macro-size atomically flat monolayer NbSe2 films on bilayer graphene terminated surface of 6H-SiC(0001) substrates by molecular beam epitaxy (MBE) method. The films exhibit an onset superconducting critical transition temperature above 6 K, 2 times higher than that of mechanical exfoliated NbSe2 flakes. Simultaneously, the transport measurements at high magnetic fields reveal that the parallel characteristic field Bc// is at least 4.5 times higher than the paramagnetic limiting field, consistent with Zeeman-protected Ising superconductivity mechanism. Besides, by ultralow temperature electrical transport measurements, the monolayer NbSe2 film shows the signature of quantum Griffiths singularity when approaching the zero-temperature quantum critical point

SARS-CoV-2 Causes a Significant Stress Response Mediated by Small RNAs in the Blood of COVID-19 Patients

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has had a serious impact on the world. In this study, small RNAs from the blood of COVID-19 patients with moderate or severe symptoms were extracted for high-throughput sequencing and analysis. Interestingly, the levels of a special group of tRNA-derived small RNAs (tsRNAs) were found to be dramatically upregulated after SARS-CoV-2 infection, particularly in coronavirus disease 2019 (COVID-19) patients with severe symptoms. In particular, the 3′CCA tsRNAs from tRNA-Gly were highly consistent with the inflammation indicator C-reactive protein (CRP). In addition, we found that the majority of significantly changed microRNAs (miRNAs) were associated with endoplasmic reticulum (ER)/unfolded protein response (UPR) sensors, which may lead to the induction of proinflammatory cytokine and immune responses. This study found that SARS-CoV-2 infection caused significant changes in the levels of stress-associated small RNAs in patient blood and their potential functions. Our research revealed that the cells of COVID-19 patients undergo tremendous stress and respond, which can be reflected or regulated by small non-coding RNA (sncRNAs), thus providing potential thought for therapeutic intervention in COVID-19 by modulating small RNA levels or activities

Homotopic Connectivity in Early Pontine Infarction Predicts Late Motor Recovery

Connectivity-based methods are essential to explore brain reorganization after a stroke and to provide meaningful predictors for late motor recovery. We aim to investigate the homotopic connectivity alterations during a 180-day follow-up of patients with pontine infarction to find an early biomarker for late motor recovery prediction. In our study, resting-state functional MRI was performed in 15 patients (11 males, 4 females, age: 57.87 ± 6.50) with unilateral pontine infarction and impaired motor function during a period of 6 months (7, 14, 30, 90, and 180 days after stroke onset). Clinical neurological assessments were performed using the Fugl–Meyer scale (FM).15 matched healthy volunteers were also recruited. Whole-brain functional homotopy in each individual scan was measured by voxel-mirrored homotopic connectivity (VMHC) values. Group-level analysis was performed between stroke patients and normal controls. A Pearson correlation was performed to evaluate correlations between early VMHC and the subsequent 4 visits for behavioral measures during day 14 to day 180. We found in early stroke (within 7 days after onset), decreased VMHC was detected in the bilateral precentral and postcentral gyrus and precuneus/posterior cingulate cortex (PCC), while increased VMHC was found in the hippocampus/amygdala and frontal pole (P < 0.01). During follow-up, VMHC in the precentral and postcentral gyrus increased to the normal level from day 90, while VMHC in the precuneus/PCC presented decreased intensity during all time points (P < 0.05). The hippocampus/amygdala and frontal pole presented a higher level of VMHC during all time points (P < 0.05). Negative correlation was found between early VMHC in the hippocampus/amygdala with FM on day 14 (r = −0.59, p = 0.021), day 30 (r = −0.643, p = 0.01), day 90 (r = −0.693, p = 0.004), and day 180 (r = −0.668, p = 0.007). Furthermore, early VMHC in the frontal pole was negatively correlated with FM scores on day 30 (r = −0.662, p = 0.013), day 90 (r = −0.606, p = 0.017), and day 180 (r = −0.552, p = 0.033). Our study demonstrated the potential utility of early homotopic connectivity for prediction of late motor recovery in pontine infarction