In Situ Observations of Halogenated Gases at the Shangdianzi Background Station and Emission Estimates for Northern China.

Halogenated gases include ozone-depleting substances and greenhouse gases, such as chlorofluorocarbons, halons, hydrochlorofluorocarbons, hydrofluorocarbons, and perfluorinated gases. In situ atmospheric observations of major halogenated gases were conducted at the Shangdianzi (SDZ) background station, China, from October 2020 to September 2021 using ODS5-pro, a newly developed measurement system. The measurement time series of 36 halogenated gases showed occasional pollution events, where background conditions represented 25% (CH2Cl2) to 81% (CF3Cl, CFC-13) of the measurements. The annual mean background mole fractions of most species at SDZ were consistent with those obtained at the Mace Head station in Ireland. The background conditions were distinguished from pollution events, and the enhanced mole fractions were used to estimate the emissions of four categories of fluorinated gases (F-gases) from northern China using a tracer ratio method. The CO2-equivalent (CO2-equiv) emission of F-gases from northern China reached 181 ± 18 Tg year-1 during 2020-2021. Among the four categories of F-gases estimated, SF6 accounted for the highest proportion of CO2-equiv emissions (24%), followed by HFC-23 (22%), HFC-125 (17%), HFC-134a (13%), NF3 (10%), CF4 (5.9%), HFC-143a (3.9%), HFC-32 (3.4%), and HFC-152a (0.2%).

High-Throughput Electromechanical Coupling Chip Systems for Real-Time 3D Invasion/Migration Assay of Cells.

Cell invasion/migration through three-dimensional (3D) tissues is not only essential for physiological/pathological processes, but a hallmark of cancer malignancy. However, how to quantify spatiotemporal dynamics of 3D cell migration/invasion is challenging. Here, this work reports a 3D cell invasion/migration assay (3D-CIMA) based on electromechanical coupling chip systems, which can monitor spatiotemporal dynamics of 3D cell invasion/migration in a real-time, label-free, nondestructive, and high-throughput way. In combination with 3D topological networks and complex impedance detection technology, this work shows that 3D-CIMA can quantitively characterize collective invasion/migration dynamics of cancer cells in 3D extracellular matrix (ECM) with controllable biophysical/biomechanical properties. More importantly, this work further reveals that it has the capability to not only carry out quantitative evaluation of anti-tumor drugs in 3D microenvironments that minimize the impact of cell culture dimensions, but also grade clinical cancer specimens. The proposed 3D-CIMA offers a new quantitative methodology for investigating cell interactions with 3D extracellular microenvironments, which has potential applications in various fields like mechanobiology, drug screening, and even precision medicine.

Characterization of haze pollution in Zibo, China: Temporal series, secondary species formation, and PMx distribution.

An online field observation was conducted in Zibo, China from September 1, 2018 to February 28, 2019, covering autumn and winter. Within the investigation period, the mean mass concentrations of PM1, PM2.5, and PM10 were 49.3, 86.1, and 136.5 µg m-3, respectively. OA (organic aerosol) was the most dominant species in PM2.5 (39.7 %), followed by NO3- (26.3 %) and SO42- (17.0 %), indicating the importance of secondary species on PM2.5. Increase of particles were always accompanied increasing relative humidity (RH), slow wind, and increasing precursors, contributing the secondary transition. SO42- was more susceptible to RH, indicating the dominant role of heterogeneous processes in its secondary formation. As RH increased, its strengthening effect on SO42- increased as well. Photochemistry was the main contributor to the secondary formation of NO3-. The morning and evening rush hours determined the peak of absolute NO3- throughout the day. By classifying particles into three bins, we found that smaller particles were the biggest contributors (larger PM1/PM2.5) of slight pollution (35 < PM2.5<115 µg m-3). When severe haze occurred, PM2.5 contributed more than particles of other sizes (PM1 or PM10). Secondary species contributed more to particles within 2.5 µm but less to larger particles. PM1/PM2.5 was high from 9:00 to 15:00, indicating the strong effect of photochemistry on smaller particles. In comparison, larger particles favored more humid conditions. NO3- preferentially existed in larger particles because the hygroscopicity of preexisting species (SO42- and NO3-) promoted partitioning. SO42- appeared a stable diurnal variation, replying its stable contribution to particles of different sizes.

Prognosis and outcome of the tympanic membrane flap at traumatic tympanic membrane perforation edge.

This study aimed to retrospectively evaluate the prognosis and outcome of tympanic membrane perforations with a particular focus on the fate of the perforation edge flaps.Chart records of 329 patients with a single ear traumatic tympanic membrane perforation were retrieved and analyzed. Of these patients, 70 were left to heal spontaneously, 93 received gelatin sponge patching treatment and 114 were subjected to otoendoscopic eardrum repair before gelatin sponge patching. The complete perforation closure rate at 3 months was 94.29% (66/70), 98.92% (92/93) and 98.24% (112/114) in the 3 groups, respectively, with no statistically significant difference (p = 0.608). The mean closure time was 28.2 ± 3.6 days in the spontaneous healing group, which was significantly longer than that in the sponge patching group (11.1 ± 2.1 days, p = 0.0017) and in the eardrum repair + sponge patching group (12.5 ± 1.9 days, p = 0.0032), while there was no significant difference between the 2 gelatin sponge patching groups (p = 1.86). The hearing ability improved in the 3 groups (6.4 ± 0.83, 7.2 ± 1.65 and 9.6 ± 2.37 dB, respectively), with no statistically significant difference (p >0.05). In the gelatin sponge patching group, new tympanic membrane tissue of the eardrum flap edge proliferated, and the contour of the eardrum flap was not obvious. In the eardrum flap repair group, the eardrum flap retracted to the perforation edge. In conclusion, the eardrum flap of the perforation edge does not have any obvious effect on the perforation closure so that it is unnecessary to conduct an intervention procedure on the flap in the clinical treatment.

Stronger secondary pollution processes despite decrease in gaseous precursors: A comparative analysis of summer 2020 and 2019 in Beijing.

To control the spread of COVID-19, China implemented a series of lockdowns, limiting various offline interactions. This provided an opportunity to study the response of air quality to emissions control. By comparing the characteristics of pollution in the summers of 2019 and 2020, we found a significant decrease in gaseous pollutants in 2020. However, particle pollution in the summer of 2020 was more severe; PM2.5 levels increased from 35.8 to 44.7 µg m-3, and PM10 increased from 51.4 to 69.0 µg m-3 from 2019 to 2020. The higher PM10 was caused by two sandstorm events on May 11 and June 3, 2020, while the higher PM2.5 was the result of enhanced secondary formation processes indicated by the higher sulfate oxidation rate (SOR) and nitrate oxidation rate (NOR) in 2020. Higher SOR and NOR were attributed mainly to higher relative humidity and stronger oxidizing capacity. Analysis of PMx distribution showed that severe haze occurred when particles within Bin2 (size ranging 1-2.5 µm) dominated. SO42-(1/2.5) and SO42-(2.5/10) remained stable under different periods at 0.5 and 0.8, respectively, indicating that SO42- existed mainly in smaller particles. Decreases in NO3-(1/2.5) and increases in NO3-(2.5/10) from clean to polluted conditions, similar to the variations in PMx distribution, suggest that NO3- played a role in the worsening of pollution. O3 concentrations were higher in 2020 (108.6 µg m-3) than in 2019 (96.8 µg m-3). Marked decreases in fresh NO alleviated the titration of O3. Furthermore, the oxidation reaction of NO2 that produces NO3- was dominant over the photochemical reaction of NO2 that produces O3, making NO2 less important for O3 pollution. In comparison, a lower VOC/NOx ratio (less than 10) meant that Beijing is a VOC-limited area; this indicates that in order to alleviate O3 pollution in Beijing, emissions of VOCs should be controlled.

Effect of treatment at different time intervals for traumatic tympanic membrane perforation on the closure.

CONCLUSION: Treatment of traumatic tympanic membrane (TM) perforation with everted or involute edge flaps at different time intervals within 1 week after the injury did not affect the perforation closure rate and mean closure time. OBJECTIVE: To retrospectively analyze the effect of treatment at different time intervals for traumatic tympanic membrane perforation with gelatin sponge patch and edge approximation plus gelfoam patching. METHODS: Patients with traumatic TM perforation visited at different days since the injury for medical treatment (1, 2, 3, 4, and 5-7 days post trauma). These patients were treated with the following prominent methods of treatment: gelatin sponge patch treatment and edge approximation plus gelfoam patching. Measurement indicators were perforation closure rate and mean closure time at 3 months. RESULTS: In the group treated with the gelatin sponge patch technique, the patients sought medical treatment at different time intervals since the injury. Accordingly, the outcome of the treatment varied in terms of the perforation closure rates achieved in different patients in this group. The respective perforation closure rates were 100%, 100%, 96%, 94%, and 89% in accordance with the time interval at which the patients were treated since the injury. The results were not significantly different when compared by statistical analysis (p > 0.05); the mean closure times in each of the different sets of cases in this group were calculated and the following values were reported: 7.1 ± 2.3, 8.2 ± 1.6, 8.7 ± 1.2, 9.2 ± 3.1, and 10.7 ± 3.9 days. On the other hand, in the edge approximation plus gelfoam patching group, the perforation closure rates were 100%, 97%, 96%, 97%, and 94%, respectively. This was in accordance with the time elapsed since the injury for the patients who visited the hospital on different days. Statistical analysis confirmed that the perforation closure rates for the different cases of this group did not have any significant difference (p > 0.05); the mean closure times were 7.6 ± 1.9, 7.9 ± 2.2, 9.2 ± 2.8, 8.5 ± 3.6, and 11.2 ± 4.1 days, respectively, indicating that differences were not significant even in terms of mean closure rates for the different cases of this group (p > 0.05).

[Evaluation of influencing factors and different repair mechanism of tympanic membrane perforations].

OBJECTIVE: Evaluation of different repair mechanism and influencing factors for Prognosis of tympanic membrane perforations. METHOD: One hundred and twelve female patients of tympanic membrane perforations were randomly divided into two groups: control group (natural repair group) and treatment group (gelatin sponge patch bonded repair group). The perforation healing were dynamically observed in two groups by endoscope. RESULT: The result show that low, medium and high perforations healing rates were 100.00%, 90.48%, 93.33%. The healing time of low, medium and high was (9.0 +/- 2.8) d, (13.0 +/- 2.6) d, (22.0 +/- 4.7) d, the epithelial layer reverse growth in 5 cases. The result show that low, medium and high perforations healing rates were 91.67%, 95.24%, 84.62%. The healing time of low, medium and high was (11.0 +/- 3.7) d, (24.0 +/- 3.8) d, (36.0 +/- 2.1) d, 2 cases were undergone surgeries. CONCLUSION: There are differences in repair mechanism between natural repair and patch bonded repair patch bonded repair can promote granulation hyperplasia, it can help recovering and lessening the patient's conductive hearing loss and occasional tinnitus. granulation hyperplasia and the healing time is closely related. The epithelial layer reverse growth may affect the healing of tympanic membrane perforation.