Research on accurate pipetting complementation model for high-throughput molecular detection platform.

The incidence of infectious diseases has risen in recent years, leading to a significant surge in the demand for medical molecular detection. High-throughput molecular detection platforms play a crucial role in facilitating rapid and efficient molecular detection. Among the various techniques employed in high-throughput molecular detection, microliquid transfer stands out as one of the most frequently utilized methods. However, ensuring the accuracy of liquid transfer poses a challenge due to variations in the physical and chemical properties of different samples and reagents. In this study, a pipetting complementation model was developed specifically for the serum, paraffin oil, and throat swabs. The aim was to enhance the transfer accuracy of diverse liquids in the context of high-throughput molecular detection, ultimately ensuring detection reliability and stability. The experimental findings revealed notable improvements in pipetting accuracy after compensating for the three liquids. In particular, the pipetting error rates decreased by 52.5, 96, and 71.4% for serum, paraffin oil, and throat swabs, respectively. These results underscore the model's effectiveness in providing reliable support for the precise transfer of liquids on the high-throughput molecular detection platform.

Extensive abundances and characteristics of microplastic pollution in the karst hyporheic zones of urban rivers.

Cities are potential areas for microplastic pollution due to large-scale production and the use of plastic products. The karst ecosystem in southwestern China is fragile, and pollutants are more likely to be transported over long distance, resulting in higher pollution risks. Understanding the abundance and composition of microplastics in karst urban water systems is crucial for microplastic pollution management in a karst region. This study investigates the abundances and characteristics of microplastics typically found in river sediments in 10 cities in karst regions of Southwest China. The results show that the abundance of microplastics in sediments ranged from 800 items·kg-1 to 4400 items·kg-1, with an average of 2273 ± 775 items·kg-1 (n = 30), indicating high abundance. Polyamide (PA) was the most common plastic polymer types in all sediment samples. The abundance of microplastics in the downstream (2527 ± 698 items·kg-1) was higher than that in the midstream (2350 ± 999 items·kg-1) and upstream areas (1943 ± 370 items·kg-1), indicating a gradual accumulation effect in the karst water systems. Microplastic abundance in cities (2119 ± 838 items·kg-1) was lower than in counties (2427 ± 671 items·kg-1). No significant correlation was found between microplastic abundance in rivers of urban areas and the level of regional population and economy, but significantly negatively correlated with the efficiency of urban sewage treatment. The results obtained from this study provided insights into the management of microplastic pollution in urban river of a karst region.

Growth, biofilm formation and atrazine degrading gene (trzN) expression of Arthrobacter sp. DNS10 cultured with montmorillonite, kaolinite and goethite.

The viable and degradation potential of the strains which adhered to soil minerals are essential for eliminating organic pollutants from soil. Herein, the interaction (growth, biofilm formation and survive) of Arthrobacter sp. DNS10, an atrazine degrading strain, with three kinds of typical soil minerals, such as montmorillonite, kaolinite and goethite, as well as the atrazine degradation gene (trzN) expression of the strain in the minerals system were studied. The results showed that montmorillonite had significant promotion effect on the growth of strain DNS10, followed by kaolinite, but goethite significantly inhibited the growth of strain DNS10. In contrast, goethite notably promoted the biofilm formation and there was less biofilm detected in montmorillonite containing system. The percentage of the survival bacteria in the biofilm that formed on montmorillonite, kaolinite and goethite was 53.8%, 40.8% and 28.2%. In addition, there were more reactive oxygen species (ROS) were detected in the cells that exposed to goethite than those of the cells exposed to kaolinite and montmorillonite. These results suggest that the electrostatic repulsion between kaolinite/montmorillonite and strain DNS10 prevents them from contacting each other and facilitates bacterial growth by allowing the strain to obtain more nutrients. Oppositely, the needle-like morphology of goethite might damage the strain DNS10 cell when they were combined by electrostatic attraction, and the goethite induced ROS also aggravate the cytotoxicity of goethite on strain DNS10. In addition, the relative transcription of trzN in the cells contacted with montmorillonite, kaolinite and goethite was 0.94-, 0.27- and 0.20- fold of the no mineral exposure treatment. Briefly, this research suggests that the minerals with different structure and/or physicochemical characteristics might cause various trend for the biofilm formation and degradation potential of the bacteria.

Effects of cascade dams on the occurrence and distribution of microplastics in surface sediments of Wujiang river basin, Southwestern China.

The influence of cascade dams on the migration of microplastics (MPs) was conducted by analyzing the spatial distribution of MPs in sediments of the Wujiang river basin (Wujiang river basin) in Southwest China. The results showed that the abundance of MPs in Wujiang river basin sediments ranged from 310 to 2620 items/kg dw (mean: 1354 items/kg dw, a high level compared with aquatic sediments worldwide). The main chemical components of these MPs were polypropylene and polyethylene. High abundance of MPs in tributary sediments suggested that tributary inputs contributed to the main stream and reservoirs. Statistical analysis showed that gross domestic product (GDP) and the basin area of cascade reservoirs, rather than hydraulic retention time and reservoir age, were the dominating factors in the distribution of MPs in the Wujiang river basin. The accumulation of MPs in cascade reservoirs implied the interception effect of cascade dams. The rapid development of cascade dam systems and the interception effect of dams should be taken into account when predicting the flux of MPs from rivers to the ocean. Heavy metals found on the surface of the MPs showed the compound pollution of MPs and heavy metals in dammed rivers and cascade reservoirs. Our results deepen the understanding of the migration of MPs in rivers alongside intensive cascade hydropower development.

Effect of cascade damming on microplastics transport in rivers: A large-scale investigation in Wujiang River, Southwest China.

Rivers are the important channels for transporting microplastics into the ocean from land. Prosperous dam construction changed the connectivity of rivers, thereby reducing the flux of microplastics to the ocean. However, this process currently lacks verification for the large-scale watersheds. In this study, we investigated the Wujiang River in China to evaluate the interception of cascade dams on microplastics. The results showed that: 1) The midstream exhibits a high abundance of microplastics (606.6-1046.2 items·kg-1) while the upstream and downstream reach exhibits relatively low pollution levels. The small-sized microplastics of 0-0.5 mm are easily migrated into downstream while the large-sized microplastics of 0.5-5 mm tend to deposit. 2) Ten kinds of plastic materials were found, in which polyethylene and polypropylene, originated from the developed tourism and fishery, account for 74.2% in all samples. 3) The earliest microplastics were found in the sediments of 1962. The abundance of microplastics in the sediments in seven reservoirs increased over time, impling the contribution of increasing human activities. 4) Positive correlations between the abundance of microplastics in sediments and local gross domestic product (GDP) (n = 33, R2 = 0.89, p < 0.05) and negative correlations between microplastics abundance and reservoir basin area (n = 33, R2 = 0.42, p < 0.05) revealed that GDP and watershed area are the key factors that control the distribution of microplastics. Our results help to understand the migration of microplastics between terrestrial and marine ecosystems.

Relationship between homocysteine level and prognosis of elderly patients with acute ischemic stroke treated by thrombolysis with recombinant tissue plasminogen activator.

BACKGROUND: Acute ischemic stroke (AIS) is mainly caused by cerebral blood flow disorders, which further leads to ischemic brain necrosis or encephalomalacia. The role of homocysteine (Hcy), an independent risk factor for cardiovascular disease, in the development of atherosclerosis is gradually revealed. However, studies are still rare and little is known about the relationship of Hcy level with the prognosis. AIM: To explore the relationship between Hcy level and prognosis in elderly patients with AIS after thrombolytic therapy with recombinant tissue plasminogen activator (rtPA). METHODS: A total of 120 patients with acute ischemic stroke who were admitted to Jingzhou Central Hospital and underwent recombinant tissue plasminogen activator treatment were randomly selected from January 2017 to December 2018. They were divided into two groups according to the level of Hcy, with 60 patients in each group. Patients with Hcy ≥ 18.54 umol/L were included into a high-level group and those with Hcy < 18.54 umol/L were included into a low-level group. The outcomes were analyzed in the two groups after the treatment. RESULTS: The National institute of Health Stroke Scale (NIHSS) scores were significantly higher in the high-level group than in the low-level group before and 1 h after the treatment (P < 0.05). There was no significant difference in NIHSS scores between the two groups at 12 and 24 h after the treatment (P > 0.05). The Modified Rankin scale (MRS) scores were significantly higher in the high-level group than in the low-level group before and 1 h after the treatment (P < 0.05). There was no significant difference in MRS scores between the two groups at 12 and 24 h after the treatment (P > 0.05). NIHSS and MRS scores were positively correlated with the prognosis after thrombolytic therapy (P < 0.05). CONCLUSION: The level of Hcy is closely related to the prognosis of elderly patients with acute ischemic stroke, and after rtPA treatment, the prognosis of elderly patients is improved significantly.

Cystitis glandularis: A controversial premalignant lesion.

Cystitis glandularis (CG) has been hypothesized as a potential precursor of adenocarcinoma, although this remains controversial. The present study reports data accumulated from 166 cases of cystitis glandularis with follow-up periods ranging between 0.5 and 17 years. The association between intestinal and typical CG and bladder carcinoma was retrospectively evaluated. The patients included in the present study had presented with typical (n=155) or intestinal (n=11) CG between 1994 and 2010. Of those patients, concurrent carcinoma of the bladder was identified in 15 (9.0%) patients, including two cases of squamous cell carcinoma and 1 case of sarcoma. The cases of carcinoma were identified either prior to or concurrently with the diagnosis of CG. Follow-up was available for 9/11 (81.8%) patients with intestinal CG. Nine months following transurethral fulguration, 8/11 (72.7%) patients were in complete remission and 1/11 (9.1%) complained of urgency and dysuria; two patients were lost to follow-up. The follow-up of the patients ranged from 0.7 to 4.5 years (median, 2.67 years; mean, 2.82 years). No evidence of subsequent carcinoma was identified in any of the patients during the follow-up of the intestinal and typical CG groups. In addition, there was no evidence of carcinoma subsequent to CG in either of the typical or intestinal CG groups. The results did not support that CG increases the future risk of malignancy in the short term and repeated cystoscopies over a short period of time are not recommended.