Sub-micron microplastics affect nitrogen cycling by altering microbial abundance and activities in a soil-legume system

Recently, the environmental and agricultural impact of plastic waste has attracted considerable attention. Here, we investigated the impact of sub-micron polyethylene (PE) and polypropylene (PP) microplastics (MPs) on nitrogen cycling, with emphasis on bacterial abundance and diversity in a soil-soybean (Glycine max) system. Exposure to soil containing MPs (50 and 500 mg kg-1) did not affect soybean growth, but significantly increased plant nitrogen uptake, which was confirmed by increased activities of nitrogenase in the soil and glutamine synthetase in soybean root. Additionally, there was an increase in 16S gene copy number and carbon and nitrogen substrate utilization, indicating increased abundance and activity of rhizosphere microbial communities. Moreover, MP contamination affected the taxonomic profile of rhizosphere bacteria, especially the abundance of symbiotic and free-living bacteria involved in nitrogen cycling. Furthermore, qPCR analysis of nitrogen-related genes and Kyoto Encyclopedia of Genes and Genomes analysis of 16S rRNA gene sequencing data revealed an increased abundance of functional genes associated with nitrogen fixation and nitrification. However, the concentration and polymer type of MPs did not have a significant impact in our system. Overall, these results provide insights into the interactions between MPs and rhizosphere bacterial communities in the soil-legume system.

Efficacy and safety of mucous fistula refeeding in preterm infants: an exploratory randomized controlled trial

BACKGROUND

This study aimed to evaluate whether mucous fistula refeeding (MFR) is safe and beneficial for the growth and intestinal adaptation of preterm infants with enterostomies.

METHODS

This exploratory randomized controlled trial enrolled infants born before 35 weeks' gestation with enterostomy. If the stomal output was ≥ 40 mL/kg/day, infants were assigned to the high-output MFR group and received MFR. If the stoma output was < 40 mL/kg/day, infants were randomized to the normal-output MFR group or the control group. Growth, serum citrulline levels, and bowel diameter in loopograms were compared. The safety of MFR was evaluated.

RESULTS

Twenty infants were included. The growth rate increased considerably, and the colon diameter was significantly larger after MFR. However, the citrulline levels did not significantly differ between the normal-output MFR and the control group. One case of bowel perforation occurred during the manual reduction for stoma prolapse. Although the association with MFR was unclear, two cases of culture-proven sepsis during MFR were noted.

CONCLUSIONS

MFR benefits the growth and intestinal adaptation of preterm infants with enterostomy and can be safely implemented with a standardized protocol. However, infectious complications need to be investigated further.

TRIAL REGISTRATION

clinicaltrials.gov NCT02812095, retrospectively registered on June 6, 2016.

Assessment of sulfidated nanoscale zerovalent iron for in-situ remediation of cadmium-contaminated acidic groundwater at a zinc smelter

Unprecedented high concentrations of heavy metals have been detected in the groundwater at a zinc smelter in Seokpo, South Korea. The outflow of the contaminated groundwater into the nearby Nakdong River must be prevented by some means such as permeable reactive barrier (PRB). As a reactive material for injection-type PRB, we have tested sulfidated nanoscale zerovalent iron (S-nZVI) to assess its efficacy in remediating the groundwater from the smelter. The S-nZVI efficiently removed Zn, Ni, and Al in the groundwater, and neutralized the groundwater to pH > 6. Sulfidation of nZVI greatly increased the removal of Cd (99.8%) compared to that by nZVI (7.2%). MINEQL+ modeling and particle characterization were performed to elucidate the forms of heavy metals in the solution and on the surface of S-nZVI. Raman and XPS results suggested that FeS on the surface of S-nZVI reacted with Cd(II) and Zn(II), forming more-stable CdS and ZnS. Sequential application of NaHCO₃ after S-nZVI treatment in a column setup was suited for the removal of remaining Zn and Fe as well as the reduction of microbial toxicity. This study guides to use of S-nZVI for in-situ remediation of cadmium-contaminated groundwater with other coexisting heavy metals from a zinc smelter.

Refinement of recto-sigmoid colon vaginoplasty using a three-dimensional laparoscopic technique

To investigate the feasibility, safety, and outcomes of three-dimensional (3D) laparoscopic vaginoplasty with a rectosigmoid colon flap for vaginal reconstruction.Following appropriate preoperative patient counseling, 17 consecutive patients underwent vaginoplasty using a 3D laparoscopic system. Perioperative and postoperative outcomes were retrospectively evaluated.Between September 2016 and February 2020, 17 patients underwent 3D laparoscopic vaginoplasty with a rectosigmoid colon flap. Of them, 15 (88%) were transgender female patients, and 2 (12%) were cisgender female patients with congenital deformities. Among the 15 transgender patients, 12 (80%) underwent de novo surgeries and 3 (20%) underwent re-do surgeries. The mean age at the time of operation was 33.0 years, and the mean total operation time was 529 ± 128 minutes. The initial intraoperative mean vaginal depth was 15.2 ± 1.3 cm, and the 30-day readmission rate was 5.9% (1/17 cases). The mean follow-up duration was 24.8 months.Perioperative and postoperative outcomes suggest that 3D laparoscopic rectosigmoid colon vaginoplasty is a potentially acceptable, effective, and safe method for vaginal reconstruction.

An Unusual Case of Colon Perforation With Multiple Transmural Ulcers After Use of Polmacoxib and Everolimus in a Metastatic Breast Cancer Patient

Everolimus (Afinitor) is an inhibitor of mammalian target of rapamycin. Polmacoxib (Acelex) is a nonsteroidal anti-inflammatory drug that belongs to the cyclooxygenase-2 (COX-2) inhibitor family and is mainly used for treatment of arthritis. Intestinal perforation has not been reported previously as a complication of everolimus, and perforation of the lower intestinal tract caused by a selective COX-2 inhibitor is extremely rare. We present here a case of colon perforation that occurred after use of polmacoxib in a metastatic breast cancer patient who had been treated with everolimus for the preceding six months.

Stigma of mental illnesses as perceived by north korean defectors living in South Korea

OBJECTIVE

This study aims to provide the information of the stigmas of mental illness such as psychosis, alcoholism, attempt suicide, and depression among North Korean defectors.

METHODS

We examined stigma for the mental illnesses of 639 North Korean defectors aged 19 to 65 years who live in the Settlement Support Center for North Korean Refugees. The stigmas of mental illnesses were assessed using the Perceived Devaluation-Discrimination Scale We directly compared the stigma level between North Korean defectors and the general population of South Korea.

RESULTS

North Korean defectors had higher perceived stigmas of psychosis and alcoholism and lower perceived stigmas of depression than South Koreans. Perceived stigma associated with attempted suicide was similar for North Korean defectors and South Koreans. Only marital status in sociodemographic variables had associations with higher perceived stigma of psychosis, alcoholism, and depression in the North Korean defectors. North Korean defectors, who spent more than one year in transit country, had associations with lower perceived stigma of psychosis and alcoholism. North Korean defectors, who had the experience of compulsory repatriation to North Korea or North Korean family in South Korea, had an association with higher perceived stigma of depression.

CONCLUSION

North Korean defectors had higher perceived stigmas of psychosis and alcoholism and lower perceived stigmas of depression than South Koreans. Further studies are needed to document serial changes in stigmas for mental illnesses associated with the receipt of education at the Settlement Support Center for North Korean defectors.