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A novel method, noted as approximate envelope method (AEM), was developed to estimate the secondary PM2.5 concentrations based on the air quality monitoring data. This approach made it possible to obtain the long‐term characteristics of the secondary PM2.5 using only conventional observations. The secondary PM2.5 concentrations and their variation characteristics under different PM2.5 pollution levels during wintertime of 2015 to 2018 in Chengdu, a major urban area of Sichuan Basin over Southwest China, were analyzed. The results showed that the secondary PM2.5 concentrations ranged from 52.3 to 122.8 μg·m−3 and accounted for 56.3%, 63.6%, and 67.4% of the total PM2.5 in slight, moderate, and heavy pollution status, respectively. Additionally, the concentrations of secondary PM2.5 increased year by year, while the concentrations of primary PM2.5 performed significant decreasing trends from 2015 to 2018. The diurnal variations of primary and secondary PM2.5 presented a significantly unimodal patterns but with maximum at morning and noon, respectively. Specific meteorological conditions such as high (low) relative humidity and temperature (wind speed and air pressure) aggravated the secondary particulate pollution in wintertime of Chengdu, reflecting an influence of regional climate change over the Sichuan Basin of Southwest China on the urban air pollution. Key Points: The PM2.5/CO ratio is a valid tracer for estimating the concentration of primary particlesSecondary particles dominated wintertime PM2.5 in urban area of Chengdu [ABSTRACT FROM AUTHOR]

Evaluation of CAS-OB refining slags showed that the melting temperature and viscosity were very high and could further increase during the CAS-OB refining process, causing excessive slag to stick to the snorkel with resulting operational problems. To avoid this, B2O3–CaO (mass ratio 1 : 1) and CaF2–CaO (mass ratio 1 : 1) were employed as modifiers added to the slag. The fusibility (melting temperature and viscosity) and desulphurising capacity of modified slag were investigated. Both B2O3–CaO and CaF2–CaO can effectively lower the melting temperature and viscosity of slag. The results of experiments on sulphur partition equilibrium between metal and slag indicate that the sulphur content of metal can be further decreased by the modified slag. [ABSTRACT FROM AUTHOR]

Investigate the biofilm-forming ability and drug resistance of Hypervirulent Klebsiella pneumoniae (HvKP) to provide scientific basis for the treatment of HvKP-infection . A total of 96 Klebsiella pneumoniae strains isolated from clinical infection specimens in Changsha Central Hospital from January to December in 2021 were retrospectively collected, and the clinical data of patients were collected. The string test preliminarily distinguished between HvKP and classic Klebsiella pneumoniae (CKP). The biofilm-forming ability of clinical strains of Klebsiella pneumoniae (KP) was determined by microplate method. The Vitek 2 Compact automatic microbial identification/drug sensitivity analysis system was used for bacterial identification and drug sensitivity test. The clinical data of patients, biofilm forming ability and drug resistance in the HvKP group and those in the CKP group were compared and analyzed. The results showed that a total of 20 strains of HvKP were isolated from 96 non-repetitive KP, and the detection rate was 20.8%. HvKP mainly come from respiratory specimens, up to 75.0%.The prevalence of hepatobiliary diseases and the infection rate of multiple sites in patients with HvKP infection were higher than those in patients with CKP infection, and the difference was statistically significant( χ 2 =5.184,7.488; P =0.023,0.006).There was no significant difference between the two groups in terms of gender, age, ICU admission, hypertension, diabetes, coronary heart disease, lung disease, urinary system disease, central nervous system disease and laboratory test indexes (all P >0.05).17 (85.0%) strains of HvKP can form biofilm, including 2 strains with weak biofilm-forming ability (10.0%), 10 strains with moderate biofilm-forming ability (50.0%) and 5 strains with strong biofilm-forming ability (25.0%). Among the 76 CKP, 71 (93.4%) could form biofilm, including 13 (17.1%) with weak biofilm-forming ability, 30(39.5%) with moderate biofilm-forming ability and 28 (36.8%) with strong biofilm-forming ability. There was no significant difference in biofilm-forming ability between HvKP and CKP ( χ 2 = 1.470, P =0.225).The overall resistance rate of HvKP was not high, but a multi-resistant HvKP resistant to carbapenems was found. The detection rate of multi-resistant HvKP (5.0%) was lower than that of multi-resistant CKP (28.9%), and the difference was statistically significant ( χ 2 =4.984, P =0.026).The resistance rate of HvKP to piperacillin/tazobactam, aztreonam, ciprofloxacin, levofloxacin, ceftazidime, cefepime, tobramycin, minocycline, doxycycline, and compound sulfamethoxazole was lower than that of CKP, and the difference was statistically significant (all P <0.05). In conclusion, most of hypervirulent Klebsiella pneumoniae can form biofilm in this study, but the difference of biofilm-forming ability is not obvious compared with classic Klebsiella pneumoniae. HvKP maintains high sensitivity to commonly used antibacterial drugs, but the drug resistance monitoring of the bacteria cannot be ignored.

Objective: To analyze the epidemiological characteristics of pneumoconiosis in Qinghai Province from 2011 to 2020, and to provide a basis for the formulation of prevention and control strategy. Methods: In April 2021 , the cases of pneumoconiosis were monitored by the Occupational Disease and Health Hazard Factors Monitoring Information System in Qinghai Province from 2011 to 2020. The distribution of pneumoconiosis, the composition of diseases and the working years exposed to dust were analyzed. Results: All 1026 cases of pneumoconiosis were newly diagnosed in Qinghai Province from 2011 to 2020, silicosis and coal worker pneumoconiosis were the main diseases (78.36% ,804/1026). Stage Ⅰ pneumoconiosis were 484 (47.17%,484/1026) cases. 359 (34.99%,359/1026) cases, 315 (30.70%,315/1026) cases and 252 (24.56%, 252/1026) cases had been diagnosed respectively in Xining City, Haidong City and Haixi Prefecture; 628 (61.21%,628/1026) cases and 418 (40.74%, 418/1026) cases engaged in mining industry and large-sized enterprise, respectively. The working years exposed to dust in silicosis cases were shorter than that in coal worker pneumoconiosis and other pneumoconiosis ( P <0.05). Conclusion: The pneumoconiosis area and industry focus in Qinghai Province is obvious. The supervision and adninistration of small and micro scale employers should be strengthened to protect the health rights and interests of workers, especially for the key area and industry.

To explore the correlation between the changes of the intestinal flora of newly treated pulmonary tuberculosis patients and the immune indicators of the body, and to provide a reference for the prevention and treatment of pulmonary tuberculosis. A single-center and case-control study was adopted. From October 2020 to April 2021, 43 patients with newly diagnosed tuberculosis in the Department of Tuberculosis, Affiliated Changsha Central Hospital,University of South China were selected as the control group. 43 cases of newly treated pulmonary tuberculosis (PTB), 43 healthy control (HC) during the same period, collected fresh feces and whole blood of subjects, and used Illumina Hiseq high-throughput sequencing technology to analyze 16S of all microorganisms in feces The V4 region of rRNA was amplified and sequenced, and the structure of the intestinal flora was analyzed by QIIME software. Use flow cytometry to determine the subject's immune indicators (CD3 + , CD4 + , CD8 + , CD4 + CD25 + CD127 - Treg, CD14 + CD16 + , CD14 + CD16 - ), and analyze the changes in intestinal flora and immune function in newly treated pulmonary tuberculosis patients Inherent connection. The χ² test, t test, and Wilcox rank sum test were used to analyze the differences in age, gender, α diversity, and relative abundance of the two groups of people. Compared with the HC group, the alpha diversity of the intestinal flora in the PTB group decreased (shannon index: t =3.906, P =0.000 2; simpson index: Z =553, P =0.004 7; chao1 index: t =5.395, P =0.000 0). β diversity analysis showed that there were significant differences in the structure of the intestinal flora between the two groups ( P =0.000). Species difference analysis showed that at the phylum level, the relative abundance of Firmicutes in the PTB group was significantly lower than that in the HC group ( Z =486.0, P =0.000 5). At the genus level, there are 15 different bacterial genera between the two groups. In the PTB group, bifidobacterium, enterococcus, lactobacillus, anaerostipes, the relative abundance of the above 5 genera of veillonella is higher than that of the HC group ( P <0.05); Butyricimonas, clostridium, and broutella (blautia), coprococcus, dorea, lachnospira, roseburia, faecalibacterium, ruminococcus, the relative abundance of 10 bacterial genera including dialister was lower than that of the HC group ( P <0.05). Comparison of immune indexes between groups showed that CD14 + CD16 + monocytes (%) in the PTB group were higher than those in the HC group ( t =2.456, P =0.001 6<0.05), while CD14 + CD16 - monocytes (%) were lower than HC ( t =-4.368, P =0.000<0.05), while the differences in CD3 + , CD4 + , CD8 + , CD4 + /CD8 + and Treg (CD4 + CD25 + CD127 - ) were not statistically significant ( P >0.05). Spearman correlation analysis showed that Firmicutes in the PTB group was negatively correlated with CD4 + /CD8 + , CD14 + CD16 + ( r =-0.218, P =0.048; r =-0.245, P =0.025), and positively correlated with CD14 + CD16 - Correlation ( r =0.250, P =0.022); At the genus level, Faecalis is positively correlated with CD4 + /CD8 + and CD4 + ( r =0.250, P =0.023; r =0.258, P =0.019); Rosella and CD3 + , CD8 + and CD14 + CD16 - are positively correlated ( r =0.27, P =0.024; r =0.219, P =0.046; r =0.027, P =0.039), and negatively correlated with CD14 + CD16 + ( r =-0.280, P = 0.01). Changes in the structure of the intestinal flora of newly treated pulmonary tuberculosis patients may be one of the influencing factors of the immune function of the body. Targeted optimization of the structure of the intestinal flora and improvement of the body's immunity may be used as an effective auxiliary treatment for pulmonary tuberculosis.

The effects of renal ischemia on spontaneous electrical activity and Fos protein expression of nucleus paragigantocellularis lateralis (PGL) in rostral ventrolateral medulla (RVLM) were observed in 67 anesthetized Sprague-Dawley rats with sinoaortic denervation by using extracellular recording and immunohistochemical techniques. The results obtained are as follows. (1) Renal ischemia increased the discharge rate from 11.40 +/- 1.08 to 21.1 +/- 1.74 spikes/s (P < 0.001) in 28 out of 30 PGL neurons, while blood pressure and heart rate had no significant change (P > 0.05). (2) Administration of 8-phenyltheophylline (8-PT), an adenosine receptor antagonist, did not affect the discharge rate of PGL neurons, but could partially inhibit the effects of renal ischemia in 17 units (P < 0.05). (3) Renal ischemia resulted in a remarkable increase in the number of Fos-like protein immunoreactive PGL neurons in the RVLM (P < 0.01). (4) Fos protein expression induced by renal ischemia was significantly inhibited by pretreatment with 8-PT (P < 0.05). Taken together, it is concluded that renal ischemia induces an increase in spontaneous electrical activity and Fos protein expression in PGL neurons of RVLM, and that adenosine released within ischemic kidney may be involved in such effects.

The present study was undertaken to define whether intracarotid injection of capsaicin induces Fos expression associated with the activation of NOS-containing neurons in brainstem nuclei by combining the immunocytochemical method for Fos with NADPH-d histochemical technique for NOS. The results obtained are as follows: (1) Intracarotid injection of capsaicin caused a significant increase of Fos-like immunoreactive neurons in area postrema (AP), nucleus tractus solitarius (NTS), paragigantocellularis lateralis (PGL) and locus coeruleus (LC), without influence upon the neurons of raphe nuclei (RN) and periaqueductal gray (PAG). (2) NO-containing neurons in PGL and NTS and the double-labeled neurons in PGL were also increased significantly following intracarotid injection of capsaicin. Small numbers of NO-containing neurons were found in LC, but there was no change in the number of NO-containing neurons in RN and PAG. No NADPH-d histochemical activity could be found in AP. (3) The above responses to capsaicin were significantly inhibited by pretreatment with either a capsaicin receptor antagonist ruthenium red or a NMDA receptor antagonist MK-801. The above results indicate that intracarotid injection of capsaicin may activate the neurons in brainstem nuclei involved in cardiovascular regulation, and that NO only plays an indirect role in the modulation of the responses of brainstem nuclei to capsaicin. These effects of capsaicin are mediated by capsaicin receptors with involvement of glutamate.

Effects of intracarotid injected capsaicin on the expression of Fos proto-oncogene in the brainstem nuclei involved in cardiovascular regulation were examined in 16 anesthetized rats with sinoaortic denervation. Only a few Fos-like protein immunoreactivity (FLI) neurons were found in the vehicle-control rats. Following intracarotid injection of capsaicin (10 micromol, 0.1 ml), the FLI neurons were markedly increased in nucleus paragigantocellularis lateralis (PGL), locus coeruleus (LC), area postrema (AP) and nucleus tractus solitarius (NTS), as compared with the results of vehicle-control rats, while the FLI neurons of raphe nuclei (RN) and periaqueductal gray (PAG) were not affected. The excitatory response to intracarotid injection of capsaicin was significantly inhibited by pretreatment with the vanilloid receptor (capsaicin receptor) antagonist ruthenium red (200 mmol, 0.1 ml). The results indicate that capsaicin may activate the neurons of the brainstem nuclei involved in cardiovascular regulation through vanilloid receptors, but does not exert any effects on PAG and RN.

Expression of c-fos protein in the medulla oblongata after baroreceptor activation by elevated intrasinus pressure (ISP) and perfusion of adenosine (Ado) was examined in 14 vascularly isolated carotid sinus perfusion rats. The results showed that Fos-like immunoreactive (FLI) neurons were distributed throughout nucleus tractus solitarius, area postrema, rostral ventrolateral medulla and nucleus raphe pallidus, and the number of FLI was increased with the elevation of ISP. Furthermore, perfusing the carotid sinus with Ado at a given ISP markedly increased the FLI in the above regions. From the results obtained, it is concluded that the c-fos expression in baroreflex pathway in medulla oblongata may be enhanced by elevated ISP and intrasinus perfusion of Ado, and Ado is capable of facilitating the baroreflex.