Transport of emerging organic ultraviolet (UV) filters in ceramic membranes: Role of polyethylene (PE) microplastics.

Microplastics can be considered potential carriers of emerging organic ultraviolet (UV) filters due to their considerable adsorption capacity in wastewater treatment. The adsorption behavior of organic UV filters, which are commonly contained in personal care products to preserve the skin against UV radiation, onto polyethylene (PE) microplastics were systematically studied to investigate their combined effects. Kinetics and isotherm analyses revealed that the adsorption of four organic UV filters onto PE microplastic surfaces followed a multi-rate and a heterogeneous multi-layer pattern. Several factors including salinity, microplastic size, and dosage also influenced the adsorption efficiency due to hydrophobic interactions. A bench-scale cross-flow ceramic membrane filtration experiment was investigated to evaluate the role of PE microplastics on the retention performance of organic UV filters. The retentions for organic UV filters were 34.2%-37.8% in the non-existence of PE microplastics. Conversely, organic UV filter retentions were significantly increased up to 82.2%-97.9% when they were adsorbed onto the PE microplastics, which were almost completely retained by the ceramic membrane. Therefore, organic UV filters can likely migrate and eventually be carried by PE microplastics, thus increasing the retention of both emerging organic UV filters and microplastics prior to discharge from wastewater treatment facilities.

Investigating the potential of ammonium retention by graphene oxide ceramic nanofiltration membranes for the treatment of semiconductor wastewater.

Ceramic membranes with high chemical and fouling resistance can play a critical role in treating industrial wastewater. In the present study, we demonstrate the fabrication of graphene oxide (GO) assembled ceramic nanofiltration (NF) membranes that provide effective ammonium retention and excellent fouling resistance for treating semiconductor wastewater. The GO-ceramic NF membranes were prepared via a layer-by-layer (LbL) assembly of GO and polyethyleneimine (PEI) on a ceramic ultrafiltration (UF) substrate. The successful fabrication of the GO-ceramic NF membranes was verified through surface characterization and pore size evaluation. We also investigated the performance of GO-ceramic NF membranes assembled with different numbers of bilayers for the rejection of ammonium ions. GO-ceramic NF membranes with three GO-PEI bilayers exhibited 8.4- and 3.2-times higher ammonium removal with simulated and real semiconductor wastewater, respectively, compared to the pristine ceramic UF substrate. We also assessed flux recovery after filtration using real semiconductor wastewater samples to validate the lower fouling potential of the GO-ceramic NF membranes. Results indicate that flux recovery increases from 39.1 % in the pristine UF substrate to 71.0 % and 90.8 % for the three- and ten-bilayers GO-ceramic NF membranes, respectively. The low-fouling GO-ceramic NF membranes developed in this study are effective and promising options for the removal of ammonium ions from semiconductor wastewater.

Peer mentoring experiences of nursing students based on the caring perspective: A qualitative study.

BACKGROUND: Care competency is a critical aspect required of nursing students who want to become nurses. Peer mentoring is a useful way to experience the natural care process. OBJECTIVES: This study aimed to explore from the caring perspective the experiences of nursing students who have participated in peer mentoring as mentors and mentees. DESIGN: This was a qualitative study; individual interviews were conducted and content analysis was performed to explore and describe peer mentoring experiences. SETTINGS: This study was conducted in the department of nursing at a university in the Republic of Korea. PARTICIPANTS: The participants were nine students in their second to fourth year who participated as mentors and mentees in the peer mentoring program organized by the department of nursing. METHODS: Data on participants' experiences of mentoring were collected through individual interviews. The transcribed content was analyzed using content analysis, and the categorized content was reorganized through the framework of the theory of caring. RESULTS: The results of the content analysis revealed five categories that formed a sequential process of caring, which became the cycle of another process of care. CONCLUSIONS: This study's findings regarding peer mentoring experiences of nursing college students indicate that the program can be effective in improving care competencies related to nursing. Peer mentoring in nursing education could be a useful method to develop students' professional competencies.

Isolated intracranial fibromuscular dysplasia of the posterior cerebral artery.

Fibromuscular dysplasia (FMD) is a nonatherosclerotic, noninflammatory arterial disease that most commonly affects the renal and internal carotid arteries, but intracranial FMD is very rare. We report a patient with FMD involving the posterior cerebral arteries (PCAs). A 24year old female was presented with a 4day history of right homonymous hemianopsia with throbbing headache in the left temporo-occipital area. The brain magnetic resonance imaging (MRI) revealed an acute ischemic stroke in the left PCA territory, while the Time of Flight (TOF) magnetic resonance angiogram (MRA) showed segmental luminal irregularities in the left proximal PCA. The conventional angiogram revealed the "string of beads" appearance, a characteristic that is pathognomonic for FMD. The patient's inhospital clinical course was stable, while there was no recurrence of stroke. This is the second report of FMD of the PCA. Notwithstanding incredibly rare incidences of isolated intracranial FMD and nonspecific findings of MRA, such a pathophysiology should be considered as the cause for a stroke in young patients, especially those with no cardiovascular risk factor.

Neuro-Behcet disease presenting as a solitary cerebellar hemorrhagic lesion: a case report and review of the literature.

BACKGROUND: Behcet's disease is a heterogeneous, multisystem, inflammatory disorder of unknown etiology. The classic triad of oral and genital ulcerations in conjunction with uveitis was originally described by the Turkish dermatologist Hulusi Behcet in 1937, but associated symptoms of the cardiovascular, central nervous, pulmonary, and gastrointestinal systems were later identified. In fact, Behcet's disease with neurological involvement (neuro-Behcet's disease) is not uncommon. Patients with neuro-Behcet's disease typically exhibit a diverse array of symptoms, most commonly in the brainstem and diencephalic regions. Herein, we report an unusual case of neuro-Behcet's disease in a patient who presented with a solitary cerebellar hemorrhage. CASE PRESENTATION: A 39-year-old Asian woman was admitted to our hospital with complaints of a sudden speech difficulty that had manifested the same morning, and dizziness and mild vomiting experienced over the previous 3 days. Magnetic resonance images revealed target-like hemorrhagic lesions in the right hemisphere of the cerebellum. Risk factors that may result in cerebellar hemorrhage, such as high blood pressure or bleeding diathesis, were ruled out, and subsequent brain angiograms were normal. CONCLUSIONS: These findings suggest that the patient's cerebellar hemorrhage could have been due to intracranial vasculitis in a rare, if not unique, complication of neuro-Behcet's disease.

Combined application of bacterial predation and carbon dioxide aerosols to effectively remove biofilms.

This study evaluated predation with Bdellovibrio bacteriovorous and CO(2) aerosol spraying to remove fluorescent Escherichia coli biofilms from silicon chips. Initial tests found that 7.5×10(5) viable E. coli cells were dispersed into the surrounding environment during aerosol treatment. The total number dispersed per test decreased to only 16 for predated biofilms. This is nearly 50,000-fold lower compared to untreated chips and 1000-fold lower compared to chips soaked in HEPES buffer only. Both scanning electron microscopy (SEM) and fluorescent microscopy analyses confirmed that predation alone did not completely eradicate the biofilm population. When used in conjunction with CO(2) aerosols, however, no fluorescent signals remained and the SEM pictures showed a pristine surface devoid of bacteria. Consequently, this study demonstrates these two methods can be used with each other to significantly remove biofilms from surfaces while also significantly reducing the likelihood of human exposure to potential pathogens during their removal.

Gas-phase removal of biofilms from various surfaces using carbon dioxide aerosols.

The present study evaluated the removal of Escherichia coli XL1-blue biofilms using periodic jets of carbon dioxide aerosols (a mixture of solid and gaseous CO(2)) with nitrogen gas. The aerosols were generated by the adiabatic expansion of high-pressure CO(2) gas through a nozzle and used to remove air-dried biofilms. The areas of the biofilms were measured from scanning electron micrographs before and after applying the aerosols. The removal efficiency of the aerosol treatment was measured with various air-drying times of the biofilms before the treatment, surface materials, and durations of CO(2) aerosols in each 8-s aerosol-nitrogen cleaning cycle. Nearly 100% of the fresh biofilms were removed from the various surfaces very reliably within 90 s. This technique can be useful for removing unsaturated biofilms on solid surfaces and has potential applications for cleaning bio-contaminated surfaces.