Stratospheric chlorine processing after the 2020 Australian wildfires derived from satellite data.

The 2019 to 2020 Australian summer wildfires injected an amount of organic gases and particles into the stratosphere unprecedented in the satellite record since 2002, causing large unexpected changes in HCl and ClONO2. These fires provided a novel opportunity to evaluate heterogeneous reactions on organic aerosols in the context of stratospheric chlorine and ozone depletion chemistry. It has long been known that heterogeneous chlorine (Cl) activation occurs on the polar stratospheric clouds (PSCs; liquid and solid particles containing water, sulfuric acid, and in some cases nitric acid) that are found in the stratosphere, but these are only effective for ozone depletion chemistry at temperatures below about 195 K (i.e., largely in the polar regions during winter). Here, we develop an approach to quantitatively assess atmospheric evidence for these reactions using satellite data for both the polar (65 to 90°S) and the midlatitude (40 to 55°S) regions. We show that heterogeneous reactions apparently even happened at temperatures at 220 K during austral autumn on the organic aerosols present in 2020 in both regions, in contrast to earlier years. Further, increased variability in HCl was also found after the wildfires, suggesting diverse chemical properties among the 2020 aerosols. We also confirm the expectation based upon laboratory studies that heterogeneous Cl activation has a strong dependence upon water vapor partial pressure and hence atmospheric altitude, becoming much faster close to the tropopause. Our analysis improves the understanding of heterogeneous reactions that are important for stratospheric ozone chemistry under both background and wildfire conditions.

Chlorine activation and enhanced ozone depletion induced by wildfire aerosol.

Remarkable perturbations in the stratospheric abundances of chlorine species and ozone were observed over Southern Hemisphere mid-latitudes following the 2020 Australian wildfires1,2. These changes in atmospheric chemical composition suggest that wildfire aerosols affect stratospheric chlorine and ozone depletion chemistry. Here we propose that wildfire aerosol containing a mixture of oxidized organics and sulfate3-7 increases hydrochloric acid solubility8-11 and associated heterogeneous reaction rates, activating reactive chlorine species and enhancing ozone loss rates at relatively warm stratospheric temperatures. We test our hypothesis by comparing atmospheric observations to model simulations that include the proposed mechanism. Modelled changes in 2020 hydrochloric acid, chlorine nitrate and hypochlorous acid abundances are in good agreement with observations1,2. Our results indicate that wildfire aerosol chemistry, although not accounting for the record duration of the 2020 Antarctic ozone hole, does yield an increase in its area and a 3-5% depletion of southern mid-latitude total column ozone. These findings increase concern2,12,13 that more frequent and intense wildfires could delay ozone recovery in a warming world.

Multi-microphone Complex Spectral Mapping for Utterance-wise and Continuous Speech Separation.

We propose multi-microphone complex spectral mapping, a simple way of applying deep learning for time-varying non-linear beamforming, for speaker separation in reverberant conditions. We aim at both speaker separation and dereverberation. Our study first investigates offline utterance-wise speaker separation and then extends to block-online continuous speech separation (CSS). Assuming a fixed array geometry between training and testing, we train deep neural networks (DNN) to predict the real and imaginary (RI) components of target speech at a reference microphone from the RI components of multiple microphones. We then integrate multi-microphone complex spectral mapping with minimum variance distortionless response (MVDR) beamforming and post-filtering to further improve separation, and combine it with frame-level speaker counting for block-online CSS. Although our system is trained on simulated room impulse responses (RIR) based on a fixed number of microphones arranged in a given geometry, it generalizes well to a real array with the same geometry. State-of-the-art separation performance is obtained on the simulated two-talker SMS-WSJ corpus and the real-recorded LibriCSS dataset.

The efficacy of probiotic preparations on inflammatory cytokines in patients with chronic kidney disease: A protocol for systematic review and meta-analysis.

BACKGROUND: Probiotics supplementation has emerged as adjuvant therapy for chronic kidney disease (CKD) in recent years. However, the effects of probiotic preparations on serum inflammatory cytokine levels are still highly controversial and poorly documented. Therefore, we performed the protocol for systematic review and meta-analysis to further clarify the effects of probiotic preparations in CKD patients. METHODS: This review will develop following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement guidelines. We searched literature published until May, 2021 thoroughly in PUBMED, Scopus, EMBASE, Web of Science, and Cochrane Library databases on May, 2021. The risk of bias of included studies was estimated by taking into consideration the characteristics including random sequence generation, allocation concealment, blinding of patients, blinding of outcome assessment, completeness of outcome data, selective reporting, and other bias by Cochrane Collaboration's tool for assessing the risk of bias. Data synthesis and analyses were performed using Stata version 10.0 software. RESULTS: The results of this systematic review and meta-analysis will be published in a peer-reviewed journal. CONCLUSION: We hypothesized that probiotic preparations may decrease the serum levels of inflammatory cytokines and protect the intestinal epithelial barrier of patients with CKD.

On the effects of the ocean on atmospheric CFC-11 lifetimes and emissions.

The ocean is a reservoir for CFC-11, a major ozone-depleting chemical. Anthropogenic production of CFC-11 dramatically decreased in the 1990s under the Montreal Protocol, which stipulated a global phase out of production by 2010. However, studies raise questions about current overall emission levels and indicate unexpected increases of CFC-11 emissions of about 10 Gg ⋅ yr-1 after 2013 (based upon measured atmospheric concentrations and an assumed atmospheric lifetime). These findings heighten the need to understand processes that could affect the CFC-11 lifetime, including ocean fluxes. We evaluate how ocean uptake and release through 2300 affects CFC-11 lifetimes, emission estimates, and the long-term return of CFC-11 from the ocean reservoir. We show that ocean uptake yields a shorter total lifetime and larger inferred emission of atmospheric CFC-11 from 1930 to 2075 compared to estimates using only atmospheric processes. Ocean flux changes over time result in small but not completely negligible effects on the calculated unexpected emissions change (decreasing it by 0.4 ± 0.3 Gg ⋅ yr-1). Moreover, it is expected that the ocean will eventually become a source of CFC-11, increasing its total lifetime thereafter. Ocean outgassing should produce detectable increases in global atmospheric CFC-11 abundances by the mid-2100s, with emission of around 0.5 Gg ⋅ yr-1; this should not be confused with illicit production at that time. An illustrative model projection suggests that climate change is expected to make the ocean a weaker reservoir for CFC-11, advancing the detectable change in the global atmospheric mixing ratio by about 5 yr.

Physicochemical Properties, Antioxidant and Antidiabetic Activities of Polysaccharides from Quinoa (Chenopodium quinoa Willd.) Seeds.

Quinoa is known for its rich nutrients and bioactive compounds. In order to elucidate the preliminary structural characteristics and biological activity of polysaccharides from quinoa (QPs), five crude polysaccharides (QPE50, QPE60, QPE70, QPE80 and QPE90) were successively fractionated by gradient ethanol, and their physicochemical properties, antioxidant and antidiabetic activities were analyzed. The results implied that their total sugar contents were 52.82%, 63.69%, 67.15%, 44.56%, and 41.01%, and their weight-average molecular weights were 13,785 Da, 6489 Da, 4732 Da, 3318 Da, and 1960 Da, respectively. Glucose was a predominantly monosaccharide in these QPs, which together in QPE50, QPE60, QPE70, QPE80, and QPE90, respectively, made up 94.37%, 87.92%, 92.21%, 100%, and 100% of the total polysaccharide. Congo red test showed that all five QPs contained triple-helix structure. The Fourier transform-infrared spectroscopy (FT-IR) and X-ray diffractometry (XRD) results suggest that the QPs form a semi-crystalline polymer constituted typical functional groups of polysaccharide including CO, CH and OH. The thermogravimetric analysis (TGA) of QPs showed that weight loss was at about 200 °C and 320 °C. The observation from scanning electron microscope (SEM) and atomic force microscope (AFM) image indicated that the morphology of QPs exhibited spherical shape. Antioxidant and antidiabetic assay exhibited that all five QPs samples had certain antioxidant and antidiabetic activities, and QPE90 showed the best antioxidant and antidiabetic activity. Overall, QPs present a promising natural source of food antioxidants and antidiabetic agents.

Investigation and analysis of standardized training for residents of general practitioners of Gansu Province in China.

BACKGROUND: China's standardized training for residents of General Practitioners (GPs) is aimed at providing the postgraduate training for family doctors who will serve the primary health care institutions. The aim of this paper is to investigate the standardized training situation, satisfaction with standardized training, work situation, intention, satisfaction and attitude of GPs who have finished standardized training. METHODS: This study was undertaken in 6 training hospitals in Gansu province using a questionnaire with 45 questions. RESULTS: Approximately 275 residents of GPs were enrolled. Finally, 263 residents completed the questionnaire (95.64% response rate), including 133 females (50.57%) and 130 males (49.43%) with an average age of 28 years (standard deviation, 1.93 years; range, 25-36 years). Additionally, 56.65% were single and 43.35% were married. Of all subjects, 92.40% residents had obtained certification of standardized training for residents of GPs and only 39.54% residents were satisfied with monthly income during training. There were 171 oriented rural medical graduates, of whom, only 42.69% expressed the willing to continue working in the primary health care institutions after the serve time (6 years) expired. Around 86.31% of residents of GPs who had finished standardized training got jobs with more than half serving in the primary health care institutions. For medical institutions and sanitary bureau were clear about general medicine policies, only 29.96% subjects registered as GPs. Among the residents in general practice department, 68.42% were engaged in the diagnosis and treatment of common disease and frequently-occurring diseases as well as referral of patients. The percentage of residents who were satisfied with the job and income were 30.40 and 14.98%, respectively. CONCLUSION: Standardized training for residents of GPs in China is gradually improving. In order to cultivate more GPs and increase their willing to serve in the primary health care institutions, it is necessary to formulate and execute better policy of GPs, publize general medicine and improve the training quality.

Clinical application of Chinese Nanjing persistent vegetative state scale.

BACKGROUND: It is a challenge to characterize the consciousness level of patients with severe disturbance of consciousness and predict their prognosis effectively for Chinese doctors. We aimed to investigate the psychometric property and the diagnostic practicality of severe disturbance of consciousness by Chinese Nanjing persistent vegetative state scale (CNPVSS) which was first set up in 1996 and modified in 2001 and 2011. METHODS: The concurrent validity, inter-rater consistency and diagnostic accuracy of CNPVSS and Chinese version of coma recovery scale-revised (CRS-R) were investigated by assessment of 380 patients with severe disorders of consciousness. RESULTS: Total scores of the CNPVSS were correlated significantly with that of the CRS-R, indicating acceptable concurrent validity. Sub-scale analysis showed moderate to high inter-rater reliability and test-retest reliability. CNPVSS was superior to CRS-R on the diagnosis sensitivity. The CNPVSS was able to distinguish 65 patients in emergence from minimal consciousness state who were misclassified as in minimal consciousness state (MCS) by the CRS-R, and it could also distinguish two patients in MCS who were misclassified as in vegetative state by the CRS-R. CONCLUSION: The CNPVSS is an appropriate measurement and is sensitive to distinguish the MCS patients from the VS patients.

Phenotypic and molecular characterisation of a novel species, Mycobacterium hubeiense sp., isolated from the sputum of a patient with secondary tuberculosis in Hubei of China.

A new fast-growing mycobacterium, designated strain QGD101T, was isolated from the sputum of an 84-year-old man suspected of tuberculosis in Wuhan Medical Treatment Center, Hubei, China. This strain was a gram-staining-negative, aerobic, non-spore-forming and catalase-positive bacterium, which was further identified as the NTM by PNB and TCH tests. The moxifloxacin and levofloxacin exhibited strong suppressing function against QGD101T with MIC values of 0.06 and 0.125 µg/ml after drug susceptibility testing of six main antimicrobial agents on mycobacteria. Based on the sequence analysis of 16S rRNA, rpoB, hsp65 and 16S-23S rRNA internal transcribed spacer, the strain QGD101T could not be identified to a species level. Mycobacterium moriokaense ATCC43059T that shared the highest 16S rRNA gene sequence similarity (98%) with strain QGD101T was actually different in genomes average nucleotide identity (78.74%). In addition, the major cellular fatty acids of QGD101T were determined as C18:1ω9c, C16:0 and C18:2ω6c. The DNA G + C content was 64.9% measured by high performance liquid chromatography. Therefore, the phenotypic and genotypic characterisation of this strain led us to the conclusion that it represents a novel species of mycobacteria, for which the name Mycobacterium hubeiense sp. nov. (type strain QGD101T = CCTCCAA 2017003T = KCTC39927T) was proposed. Thus, the results of this study are very significant for the clinical diagnosis of tuberculosis and future personalised medicine.

Complex Spectral Mapping for Single- and Multi-Channel Speech Enhancement and Robust ASR.

This study proposes a complex spectral mapping approach for single- and multi-channel speech enhancement, where deep neural networks (DNNs) are used to predict the real and imaginary (RI) components of the direct-path signal from noisy and reverberant ones. The proposed system contains two DNNs. The first one performs single-channel complex spectral mapping. The estimated complex spectra are used to compute a minimum variance distortion-less response (MVDR) beamformer. The RI components of beamforming results, which encode spatial information, are then combined with the RI components of the mixture to train the second DNN for multi-channel complex spectral mapping. With estimated complex spectra, we also propose a novel method of time-varying beamforming. State-of-the-art performance is obtained on the speech enhancement and recognition tasks of the CHiME-4 corpus. More specifically, our system obtains 6.82%, 3.19% and 2.00% word error rates (WER) respectively on the single-, two-, and six-microphone tasks of CHiME-4, significantly surpassing the current best results of 9.15%, 3.91% and 2.24% WER.

Effect of azithromycin in combination with simvastatin in the treatment of chronic obstructive pulmonary disease complicated by pulmonary arterial hypertension.

OBJECTIVE: To evaluate the effect of azithromycin in combination with simvastatin in the treatment of chronic obstructive pulmonary disease (COPD) complicated by pulmonary arterial hypertension. METHODS: Eighty-six patients who developed COPD and pulmonary arterial hypertension and received treatment from August 2013 to October 2014 were selected and randomly divided into an observation group and a control group using random number table, 43 in each group. Patients in the control group were orally administrated 20 mg of simvastatin, once a day. Patients in the observation group took 0.25g of azithromycin enteric-coated tablets, once a day, besides simvastatin. The treatment course of both groups was six months. Blood gas analysis indexes, forced expiratory volume in first second (FEV1), six minutes walking distance, dyspnea grade and blood lipid parameter were recorded and compared between the two groups. RESULTS: Arterial partial pressure of oxygen (PaO2) and arterial partial pressure of carbon dioxide (PaCO2) of the observation group were (68.13±3.03) mmHg and (45.08±2.27) mmHg after treatment, respectively. In the control group, the values were (60.01±4.72) mmHg and (38.93±1.61) mmHg, respectively. The improvement amplitude of the observation group was superior to that of the control group (P<0.05). FEV1, forced vital capacity (FVC) and 6-minutes walking distance of the observation group were (1.08±0.11) L, (2.1±0.2) L and (380.34 ± 31.28) m respectively after treatment, superior to the control group ((0.93±0.09) L, (1.7±0.1) L) and (302.79±29.74) m, and the difference had statistical significance (P<0.05). The levels of peripheral systolic blood pressure (PSBP) and peripheral diastolic blood pressure (PDBP) of patients in the observation group were both lower than those of the control group, and the difference had statistical significance (P<0.05). CONCLUSION: Azithromycin in combination with simvastatin has definite effect in the treatment of COPD in combination with pulmonary arterial hypertension as it can significantly relieve ventilation disturbance, improve lung function, and decrease pulmonary arterial pressure. Hence it is worth clinical promotion.

An automated integrated platform for rapid and sensitive multiplexed protein profiling using human saliva samples.

During the last decade, saliva has emerged as a potentially ideal diagnostic biofluid for noninvasive testing. In this paper, we present an automated, integrated platform useable by minimally trained personnel in the field for the diagnosis of respiratory diseases using human saliva as a sample specimen. In this platform, a saliva sample is loaded onto a disposable microfluidic chip containing all the necessary reagents and components required for saliva analysis. The chip is then inserted into the automated analyzer, the SDReader, where multiple potential protein biomarkers for respiratory diseases are measured simultaneously using a microsphere-based array via fluorescence sandwich immunoassays. The results are read optically, and the images are analyzed by a custom-designed algorithm. The fully automated assay requires as little as 10 µL of saliva sample, and the results are reported in 70 min. The performance of the platform was characterized by testing protein standard solutions, and the results were comparable to those from the 3.5 h lab bench assay that we have previously reported. The device was also deployed in two clinical environments where 273 human saliva samples collected from different subjects were successfully tested, demonstrating the device's potential to assist clinicians with the diagnosis of respiratory diseases by providing timely protein biomarker profiling information. This platform, which combines noninvasive sample collection and fully automated analysis, can also be utilized in point-of-care diagnostics.

[Design and implementation of projection-initialized wall filter in ultrasonic imaging].

Wall filtering is a key technology in ultrasound color flow imaging system. Without efficient suppression of wall signal originating from stationary and moving tissue, low velocity blood flow cannot be measured, and the estimates of higher velocities will have a large bias. Among the various wall filters, the projection-initialized infinite impulse response (IIR) wall filter has narrow transition bandwidth and high stopband suppression ratio; it is superior to other wall filters. At present, the related literatures are only limited to theoretical research on this kind of filter, and no feasible design and implementation methods are reported. In this paper, a new design and implementation scheme for the projection-initialized filter is proposed, which transforms the filtering process to matrix multiplications. The proposed scheme is realized on programmable logic devices. Experimental results show that it is a simple and effective implementation method for projection-initialized IIR filter, and it is superior to conventional wall filters.

Gaussian wavelet based dynamic filtering (GWDF) method for medical ultrasound systems.

In this paper, a novel dynamic filtering method using Gaussian wavelet filters is proposed to remove noise from ultrasound echo signal. In the proposed method, a mother wavelet is first selected with its central frequency (CF) and frequency bandwidth (FB) equal to those of the transmitted signal. The actual frequency of the received signal at a given depth is estimated through the autocorrelation technique. Then the mother wavelet is dilated using the ratio between the transmitted central frequency and the actual frequency as the scale factor. The generated daughter wavelet is finally used as the dynamic filter at this depth. Frequency-demodulated Gaussian wavelet is chosen in this paper because its power spectrum is well-matched with that of the transmitted ultrasound signal. The proposed method is evaluated by simulations using Field II program. Experiments are also conducted out on a standard ultrasound phantom using a 192-element transducer with the center frequency of 5 MHz. The phantom contains five point targets, five circular high scattering regions with diameters of 2, 3, 4, 5, 6 mm respectively, and five cysts with diameters of 6, 5, 4, 3, 2 mm respectively. Both simulation and experimental results show that optimal signal-to-noise ratio (SNR) can be obtained and useful information can be extracted along the depth direction irrespective of the diagnostic objects.

A novel clutter rejection scheme in color flow imaging.

In ultrasound color flow imaging systems, it is important to suppress the clutter signals originated from stationary and slowly moving tissue sufficiently. Without sufficient clutter rejection, the estimation of the blood flow velocity will be inaccurate, and the imaging quality will be poor. In this paper we present a new clutter rejection scheme involving first down-mixing the clutter signals to zero frequency and then cancelling the stationary echo by subtracting the signals from two consecutive pulses. This stationary echo cancelling scheme is easy to be realized with small computational power, and is adaptive to the clutter signals. Theoretical analysis and simulation using RF data prove that it's an efficient and practical clutter rejection scheme for color flow imaging.

An improved mean frequency estimator for ultrasonic color flow imaging using second-order autoregressive model.

An improved second-order AR estimator is proposed for color flow imaging. It can give accurate estimation in the presence of very intensive clutter signal. Traditionally, the performance of the second-order AR estimator may be degraded by the clutter when the amplitude of the clutter is very large compared with the Doppler signal, because very large clutter will shift the Doppler pole toward low frequency. The improved second-order AR estimator which we propose in this paper can remedy this problem by first estimating the mean frequency of the clutter signal and then compensating the frequency down-shift of the Doppler signal using this mean frequency. Simulation results show that the improved AR estimator can give more accurate estimate of the mean frequency and variance of the blood signal than the conventional one, even if the amplitude of the clutter is very large compared with Doppler signal.

An novel clutter rejection filters applied to wideband blood flow velocity estimation.

Color flow imaging plays a major role in the diagnosis of many vascular diseases, especially cardiovascular disease. The imaging quality is highly influenced by the clutter originating from the vascular wall, stationary and slowly moving tissues and relative motion between the probe held by doctor and the blood flow. The clutter rejection filter in front of the mean frequency estimator will restrict the mean frequency estimation range because the power of the signal component induced by slowly moving blood is suppressed as well. Therefore, a novel scheme, using parameter estimation methods based on the two-dimensional correlation function model (2DCM) and the conventional down mixing, is proposed to clutter rejection. With the parameter estimation methods based on the 2DCM, both the center frequency and the mean Doppler frequency are estimated. The two dimensional information in range gate has been also sufficiently used. Simulation results have shown that this adaptive scheme has achieved superior performance in wideband blood flow velocity estimation.

[The research on monoamine neurotransmitters changes in plasma and cerebrospinal fluid in patients with persistent vegetative state].

AIM: To study the relationships between the pathogenesis of persistent vegetative state (PVS) and the levels of monoamine neurotransmitters in plasmas and cerebrospinal fluids (CSFs) in patients with PVS. METHODS: The high-pressure liquid chromatography (HPLC) was used to detect. RESULTS: It was found that the level of dopamine (1.95 +/- 0.99) was significantly increased in plasma compared with the control (1.16 +/- 0.47) (P < 0.05), but the levels of 5-HT, TYR, TRP, GABA of plasma were insignificantly changed. In cerebrospinal fluid, the level of DA was insignificantly changed, and the level of 5-HT (0.49 +/- 0.32) was significantly decreased compared with the control (1.02 +/- 0.35) (P < 0.05), but the levels of TYR (1.36 +/- 0.11), TRP (0.63 +/- 0.40), GABA (1.15 +/- 0.61) were significantly increased respectively compared with the controls (0.40 +/- 0.24; 0.29 +/- 0.22; 0.37 +/- 0.45) (P < 0.05; P < 0.05; P < 0.01). The levels of GABA and DA in plasma were significant correlated (P < 0.05), and GABA and DA in CSF were also significant correlated (P < 0.01). CONCLUSION: The results of this study suggested that PVS is related to the decrease of 5-HT in CSF and the increase of DA in plasma.