[Bibliometric and visual analysis of neurological damage caused by electrical welding operations].

Objective: To analyze and summarize the trends and hot spots in the field of neurological damage caused by electric welding operations, and to provide ideas for new researches by searching the domestic and international literature. Methods: In December 2022, using Web of Science Citation Index (Web of Science), China Journal Full-Text Database (CNKI) and Wanfang Database as search databases, literature search was conducted on the Chinese and English search terms related to eletrical welding operations and neurological damage. The bibliometric analysis software VOSviewer 1.6.18 and CiteSpace 6.1.6 were used to visualize the publication year, publication quantity, country, research institution and key words of the literature. Results: A total of 309 articles (112 in Chinese and 197 in English) were included in this study. The first domestic and international papers were published in 1976 and 1994 respectively, and the number of papers reached the peak in 2006 and 2018, and then showed a downward trend to varying degrees. In China, Shandong First Medical University (including Shandong Institute of Occupational Health and Occupational Disease Prevention and Shandong Academy of Medical Sciences) and Wuhan University of Science and Technology had the largest number of publications. The 309 articles were from 52 Chinese journals and 86 English journals. The co-occurrence analysis of key words showed that the domestic research mainly focused on eletrical welding operation, welding workers, neurobehavioral function and manganese, and the nervous system damage caused by manganese in welding smoke was the field of international attention. Long term exposure, risk, and performance were key buzzwords in the field. Conclusion: The research focus in the field of nervous system damage caused by electric welding operation has an obvious trend of time evolution, gradually transiting from clinical manifestations to its toxic mechanism and early biomarkers.

[Analysis of the first national public health practice skills competition among college students].

To analyze the difficulty, distinction and result of the first national public health practice skills competition among college students, it showed the general situation of this competition, and discussed the present situation, problems and countermeasures of skills training for students majoring in preventive medicine. Based on such competition, educators can promote teaching reform and post competency training.

[Therapeutic effect of miR-489 in a mouse model of silica-induced matured pulmonary fibrosis].

Objective: To explore the potential therapeutic role of miR-489 in silica-induced pulmonary fibrosis mouse models. Methods: A total of 32 C57BL/6 male mice were randomly divided into four groups: saline, silica, silica plus miRNA control and silica plus miR-489 agomir (n=8 in each group) . The mice were instilled with silica particles suspended in saline or sterile saline intratracheally. Subsequently, miR-489 agomir or miRNA control was injected via the tail vein into each mouse at days 28, 35, 42 and 49, the miR-489 levels, histological examination, collagen deposition, fibrotic biomarkers (E-cadherin, α-SMA, Vimentin, Fibronectin) and transforming growth factor-ß(1) (TGF-ß(1)) protein levels in mouse lung tissues were measured. Results: miR-489 levels in silica plus miR-489 group were significantly increased in lung tissues compared with silica plus miRNA control group (P<0.05) . Histological examination showed attenuated inflammation, less severe fibrotic foci and less destruction of alveolar architecture in the silica plus miR-489 group. Additionally, both the severity and distribution of lung lesions were ameliorated in silica plus miR-489 group compared with the silica plus miRNA control group (P<0.05) . The collagen deposition and hydroxyproline levels in silica plus miR-489 group were significantly decreased compared with the silica plus miRNA control group (P<0.05) . These changes were supported by decreased protein levels of α-SMA, Vimentin, Fibronectin, TGF-ß1 along with increased protein levels of E-cadherin in silica plus miR-489 group (P<0.05) . Conclusion: Our data indicate that the upregulation of miR-489 has potential therapeutic role in silica-induced pulmonary fibrosis in vivo, which may be associated with the depression of TGF-ß1 release.

MBR/RO/ozone processes for TFT-LCD industrial wastewater treatment and recycling.

This research is mainly to explore the treatment capacity for TFT-LCD industrial wastewater recycling by the processes combined with membrane bioreactor (MBR), reverse osmosis (RO) and ozone(O3). The organic wastewater from the TFT-LCD industry was selected as the target. MBR, RO and ozone plants were established for evaluation. An MBR plant consisted of a 2-stage anoxic/aerobic bioreactor and an immersed UF membrane unit was employed. The effluent of MBR was conducted into the RO system then into the ozone system. The RO system consisted of a spiral membrane in the vessel. One bubble column, 75 cm high and diameter 5 cm, were used as the ozonation reactor. On the bottom of ozonation reactor is a porous diffuser for releasing gas, with an aperture of 100 microm (0.1 cm). Over the whole experimental period, the MBR process achieved a satisfactory organic removal. The COD could be removed with an average of over 98.5%. For the TOC item, the average removal efficiency was 97.4%. The stable effluent quality and satisfactory removal performance were ensured by the efficient interception performance of an immersed UF membrane device incorporated with the biological reactor. Moreover, the MBR effluent did not contain any suspended solids and the SDI value was under 3. After the treatment of RO, excellent water quality was found. The water quality of permeate was under 5 mg/I, 2 mg/l and 50 micros/cm for COD, TOC and conductivity respectively. The treated water can be recycled and reused for the cooling tower make-up water or other purposes. After the treatment of ozone, the treated water quality was under 5 mg/l and 0.852 mg/l for COD and TOC respectively. The test results of MBR, MBR/RO and MBR/RO/ozone processes were compared as possible appropriate treatment technologies applied in TFT-LCD industrial wastewater reuse and recycling.

Biological nitrification and denitrification of opto-electronic industrial wastewater.

Development and application of biological nutrient removal processes accelerated significantly over the past decade due to more stringent nutrients (nitrogen and phosphorus) discharge limits being imposed on wastewater treatment plants. The opto-electronic industry has developed very fast over the past decade in the world. The wastewater often contains a significant quantity of organic nitrogen compounds and has a ratio of over 95% in organic nitrogen (Org-N) to total nitrogen (T-N). In this study, a 2-stage Anoxic/Aerobic pre-denitrification process was established and the efficiency of wastewater treatment was evaluated. Wastewater from an actual LCD-plant was obtained as the sample for looking into the feasibility of opto-electronic industrial wastewater treatment. Hydraulic retention time (HRT) and mixed liquor recycle rate (MLR) were controlled independently to distinguish between the effects of these two factors. Under suitable HRT and mixed liquor recycle ratio, effluents of NH4-N, NOx-N and COD can fall below 20 mg/l, 30 mg/l and 80 mg/l.

Application of a membrane bioreactor system for opto-electronic industrial wastewater treatment--a pilot study.

The membrane bioreactor (MBR) system has become more and more attractive in the field of wastewater treatment. It is particularly attractive in situations where long solids retention times are required, such as nitrifying bacteria, and physical retention is critical to achieving more efficiency for biological degradation of pollutants. Although it is a new technology, the MBR process has been applied to industrial wastewater treatment for only the past decade. The opto-electronic industry, developed very fast over the past decade in the world, is a high technological manufacturing industry. The treatment of the opto-electronic industrial wastewater containing a significant quantity of organic nitrogen compounds, with a ratio over 95% in organic nitrogen (Org-N) to total nitrogen (T-N), is very difficult to meet the discharge limits. The purpose of this research is mainly to discuss the treatment capacity of high-strength organic nitrogen wastewater, and to investigate the capabilities of the MBR process. A 2 m3/day capacity MBR pilot plant consisting of anoxic and aerobic tanks and a membrane bioreactor was installed for evaluation. The operation was continued for 130 days. Over the whole experimental period, a satisfactory organic removal performance was achieved. The COD could be removed with an average of over 94.5%. For TOC and BOD5, the average removal efficiencies were 96.3 and 97.6%, respectively. The nitrification and denitrification were also successfully achieved. The effluent did not contain any suspended solids. Only a small concentration of ammonia nitrogen was found in the effluent. The stable effluent quality and satisfactory removal performance mentioned above were ensured by the efficient interception performance of the membrane device incorporated within the biological reactor. The MBR system shows promise as a means of treating very high organic nitrogen wastewater without dilution. The effluent of TKN, NOx-N and COD can fall below 20 mg/L, 30 mg/L and 50 mg/L.

Nitrification-denitrification of opto-electronic industrial wastewater by anoxic/aerobic process.

This research focused on the biological treatment of high-strength organic nitrogen wastewater, and presented the results from the nitrification and denitrification of an actual industrial wastewater using anoxic/aerobic process. The opto-electronic industrial wastewater often contains a significant quantity of organic nitrogen compounds and has a ratio over 95% in organic nitrogen (Org-N) to total nitrogen (T-N). In this study, a 2-stage anoxic/aerobic process was established and evaluated the efficiency of wastewater treatment. Raw wastewater from an actual TFT-LCD manufacturing plant was obtained as the sample for looking into the feasibility of opto-electronic industrial wastewater treatment. After toxicity identification evaluation (TIE) test of raw wastewater. the inhibition was related to organic nitrogen (TMAH, MEA) and unionized ammonia (free ammonia, NH3) with high pH. Therefore, pH control is important for biological treatment of high-strength organic nitrogen industrial wastewater. Besides. hydraulic retention time (HRT) and mixed liquor recycled rate (MLR) were controlled independently to distinguish between the effects of these two factors. Under suitable HRT ( > 1.7 d) and mixed liquor recycled rate (< 4Q), effluent of NH4-N. NO3-N + NO2-N, and COD can fall below 20 mg/L, 30 mg/L, and 80 mg/L. The anoxic/aerobic process removed 92-98% of the carbon source, and approximately 80% of TKN, 70% of T-N.

Recycling and reuse of wastewater from a new-developed community using sand filtration, ultrafiltration, and ozonation.

In this study, the pilot apparatus combined with sand filtration, ozonation and ultrafiltration was established. Wastewater from the secondary treatment effluent in the new-developed community was taken as the sample for looking into the feasibility of domestic wastewater reuse and recycling. The test results by sand filtration, sand filtration/ultrafiltration, sand filtration/ozonation, and sand filtration/ultrafiltration/ozonation were compared for looking for appropriate treatment processes applied in the domestic wastewater reuse and recycling. Finally, cost analysis was carried out and sand filtration/ozonation process was suggested to be one of the best processes. The total cost is about 0.1-0.32 USD dollars per cubic meter of produced water by considering the capital and operation cost for five years in the small domestic wastewater treatment plant (50-750 CMD).

High-strength nitrogen removal of opto-electronic industrial wastewater in membrane bioreactor--a pilot study.

The membrane bioreactor (MBR) system has become more and more attractive in the field of wastewater treatment. It is particularly attractive in situations where long solids retention times are required, such as nitrifying bacteria, and physical retention critical to achieving more efficiency for biological degradation of pollutant. Although it is a new technology, the MBR process has been applied for industrial wastewater treatment for only the past decade. The opto-electronic industry, developed very fast over the past decade in the world, is high technology manufacturing. The treatment of the opto-electronic industrial wastewater containing a significant quantity of organic nitrogen compounds with a ratio over 95% in organic nitrogen (Org-N) to total nitrogen (T-N) is very difficult to meet the discharge limits. This research is mainly to discuss the treatment capacity of high-strength organic nitrogen wastewater, and to investigate the capabilities of the MBR process. A 5 m3/day capacity of MBR pilot plant consisted of anoxic, aerobic and membrane bioreactor was installed for evaluation. The operation was continued for 150 days. Over the whole experimental period, a satisfactory organic removal performance was achieved. The COD could be removed with an average of over 94.5%. For TOC and BOD5 items, the average removal efficiencies were 96.3 and 97.6%, respectively. The nitrification and denitrification was also successfully achieved. Furthermore, the effluent did not contain any suspended solids. Only a small concentration of ammonia nitrogen was found in the effluent. The stable effluent quality and satisfactory removal performance mentioned above were ensured by the efficient interception performance of the membrane device incorporated within the biological reactor. The MBR system shows promise as a means of treating very high organic nitrogen wastewater without dilution. The effluent of TKN, NOx-N and COD can fall below 20 mg/L, 30 mg/L and 50 mg/L.

Catalytic ozonation of 2-dichlorophenol by metallic ions.

This research is mainly to explore functional improvement by adding various kinds of metallic ions in the ozonation of 2-chlorophenol solution. During the experiment, various kinds of metallic ions (Pb+, Cu2+, Zn2+, Fe2+, Ti2+, and Mn2+) were added; it was found that the reaction rate increased in all cases. The best result was obtained by using manganese ions, followed by iron and titanium ions. At pH = 3 and 1 ppm Mn2+ concentration, the reaction rate was increased by three times. TOC removal rate was also increased from 12.6% to 38% at 60 min reaction time. Ozone self-decomposition with various kinds of metallic ions alone was tested. It was found the ozone self-decomposition coefficient is highly dependent on the reaction rate constant for ozonation of 2-chlorophenol. The improvement of reaction was relevant to the mechanism of reaction between ozone and metallic ions. Furthermore, the effect of adding manganese ions was studied. With the initial manganese concentration at 0-2 ppm, after gas exposure for 20 min the removal rate can be increased from 38% to 93%. TOC removal rate was increased from 11% to 38%. The reaction rate was improved more greatly at the initial pH = 3.

Ozonation of domestic secondary effluent for recycling and reuse--a pilot plant study.

In this study, a pilot plant combined ozonation with sand filtration is established. Wastewater from the secondary effluent was taken as the sample for looking into the feasibility of domestic wastewater recovery and recycling. At the beginning, a series of hydraulic analysis and ozone transfer tests was conducted in the bubble column reactor. From these tests, it was found that when the gas flow is controlled to within 0.2 to approximately 1.0 L/min and liquid flow within 0.5 to approximately 2.5 L/min, using series connected mixing tank model for our calculation, the result J (CSTR) is 1 to approximately 2. From the ozone transfer test it is known that the smaller the gas flow, the better the transfer rate, and the same pattern occurs on ozone gas concentration. After sand filtration and ozone treatment, the G/L ratio within the ozone column reactor can be maintained within 0.2 to approximately 0.4 and the ozone dosage within 8 to approximately 12 mg/L. The removal rate for coliform bacillus, BOD, turbidity and color is 99.96%, 62.2%, 89.6% and 67% respectively. After ozonation treatment, coliform bacillus content can be controlled under 10 CFU/mL, BOD under 10 mg/L, turbidity within 2.0 to approximately 2.5 (NTU), and color within 10.3 to approximately 13.7 degree. The recycled water is almost colorless and odorless, and is capable of reaching the reference standard for recycled water.

Heterogeneous catalytic ozonation of 2-chlorophenol aqueous solution with alumina as a catalyst.

Heterogenous catalytic ozonation of 2-chlorophenol (2-CP) in the presence of gamma-alumina as a solid catalyst has been investigated in this research. It showed that the rate for degradation of TOC could increase from 21% to 43%. The pseudo-first reaction constants of 2-CP could increase from 0.8688 min-1 to 0.1270, increasing by approximately 40%. At the same time, the consumption of ozone was only half that of ozone alone. This research also explored the effects of the catalyst dosage, pH values and removal kinetics of 2-CP. In addition, three consecutive running with the same catalyst revealed insignificant reduction of the activity. Furthermore, the elimination of toxicity was evaluated by Microtox analysis. The detoxification was more stable and with good results.

[Climbing-upward inhibition of Oncomelania hupensis by niclosamide combination].

OBJECTIVE: To develop a combination of molluscicide/insecticide with a good molluscicidal effect, especially an inhibitory effect on climbing-upward of Oncomelania hupensis. METHODS: Experiments on molluscicidal and snail-climbing inhibition effect of the combination of niclosamide and shachongding [(dimethylamine) trithacyclohexane hydrochloride] were conducted by immersion and spraying in laboratory. RESULTS: The combination of niclosamide (0.2 mg/L) and shachongding (0.1 mg/L) showed an inhibition of 92.67% of snails to climb up. There was no significant difference in molluscicidal effect between the combination (LC90 0.198 mg/L) and niclosamide alone (LC90 0.207 mg/L). CONCLUSION: The combination showed an effective inhibition on the climbing-upward of snails in water so as to improve the molluscicidal effect and reduce the cost of mollusciciding.

Strain complex of Schistosoma japonicum in the mainland of China.

The present paper deals with studies on the characteristics of Schistosoma japonicum isolated from five localities in the mainland of China. The following items were observed and compared including morphometric data, susceptibility of six mammalian hosts, prepatent period, compatibility between larvae and snail hosts, size of hepatic granuloma produced by eggs, immunoreactions in experimental animals, sensitivity to praziquantel, SDS-PAGE protein pattern and its antigenicity analysis, DNA hybridization and genetic variation and differentiation by analysis with multilocus enzyme electrophoresis. By means of these multidisciplinary methods, from morphological to molecular level, the following conclusions may be drawn from our results. The evidence indicates firstly that S. japonicum in the mainland of China comprises a strain complex with several components of geographically distributed strains. At least four distinct strains exist, ie Yunnan, Guangxi, Sichuan and Anhui-Hubei. Characteristics of each strain are distinct and the results of these studies lead to discussion on the problem of the intraspecific and interstrain differentiation of S. japonicum in the mainland of China.

Compatibility between Oncomelania hupensis and different isolates of Schistosoma japonicum in China.

Oncomelania hupensis from six localities were used for infection with different isolates of Schistosoma japonicum in the mainland of China, ie Anhui in the east, Hubei in the center, Guangxi in the south, Sichuan in the West, Yunnan in the southwest and Fujian in the southeast. Snails from Anhui and Hubei were readily infected with the local isolate of S. japonicum and cross infection also took place readily between the snails and the schistosomes from these two places. Snails from Sichuan and Yunnan were refractory to infection with schistosome isolates from Hubei and Anhui, but the isolates from Sichuan and Yunnan were able to develop in snails from Hubei and Anhui. Though the Guangxi isolate developed readily in both Anhui and Guangxi snails, the average precercarial period in the former was significantly longer than in the latter. None of the other snails from Sichuan, Yunnan and Fujian became infected. On the other hand, snails from Guangxi infected with Anhui parasites also had a longer precercarial period than that in Anhui snails. Snails from Fujian were readily infected with the isolates from Anhui and Yunnan. The present results suggest that there might be different geographic strains of S. japonicum and their Oncomelania snail hosts in the mainland of China.

[Studies on the strain differences of Schistosoma japonicum in the mainland of China. I. Compatibility between schistosomes and their snail hosts].

Oncomelania hupensis hupensis from six localities were used in this study, i.e. Guichi of Anhui in the east, Jianli of Hubei in the middle, Guiping of Guangxi in the south, Tianquan of Sichuan and Eryuan of Yunnan in the southwest and Fuqing of Fujian in the southeast. Snails from each locality were individually cross-exposed to 20 miracidia of the different isolates of S. japonicum from the above-named places, with the exception of Fujian Province where no snail could be found naturally infected with S. japonicum. The results showed that snails from one locality were readily infected with the local isolate of S. japonicum. Besides, cross infection also took place readily between the snails and the schistosomes from Hubei and Anhui with snail infection rates of 43.8% and 40.9% respectively. Snails from Sichuan and Yunnan were refractory to infection with schistosome isolates from Hubei and Anhui, but the isolate from Sichuan was able to develop in Oncomelania snails from Hubei and Anhui, resulting in infection rates of 10.2% and 4.5% while that from Yunnan, in snails from Hubei and Anhui in infection rates of 33.6% and 10.8% respectively. Though the Guangxi isolate of S. japonicum developed readily in both Anhui (30.7%) and Guangxi snails (9.4%), the average precercarial period was 100.9 days in the former which was significantly longer than 76.9 days in the latter. None of the other snails from Sichuan, Yunnan and Fujian became infected. On the other hand, snails from Guangxi infected with Anhui parasites also had a longer precercarial period of 92.7 days compared with that of 81.6 days in Anhui snail.(ABSTRACT TRUNCATED AT 250 WORDS)