1,248 research outputs found
High-Affinity Phosphate-Binding Protein (PBP) For Phosphorous Recovery: Proof of Concept Using Recombinant \u3cem\u3eEscherichia coli\u3c/em\u3e
Phosphorus (P) is a critical, non-renewable nutrient; yet excess discharges can lead to eutrophication and deterioration of water quality. Thus, P removal from water must be coupled with P recovery to achieve sustainable P management. P-specific proteins provide a novel, promising approach to recover P from water. Bacterial phosphate-binding proteins (PBPs) are able to effectively remove phosphate, achieving extremely low levels in water (i.e. 0.015 mg-P L−1). A prerequisite of using PBP for P recovery, however, is not only removal, but also controlled P release, which has not yet been reported. Phosphate release using recombinant PBP-expressing Escherichia coli was explored in this study. Escherichia coli was genetically modified to overexpress PBP in the periplasmic space. The impacts of ionic strength, temperature and pH on phosphate release were assessed. PBP-expressed E. coli demonstrated consistently superior ability to adsorb more phosphate from liquid and release more phosphate under controlled conditions relative to negative controls (unexpressed PBP E. coli and E. coli K12). Lower pH (3.8), higher temperature (35ºC) and higher ionic strength (100 mM KCl) facilitated increased phosphate release, providing a maximum of 2.1% P recovery within 3 h. This study provides proof of concept of the feasibility of using PBP to recover P
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Elevated numbers of PD-L1 expressing B cells are associated with the development of AIDS-NHL.
The risk for non-Hodgkin lymphoma (NHL) is markedly increased in persons living with human immunodeficiency virus (HIV) infection, and remains elevated in those on anti-retroviral therapy (cART). Both the loss of immunoregulation of Epstein-Barr virus (EBV) infected cells, as well as chronic B-cell activation, are believed to contribute to the genesis of AIDS-related NHL (AIDS-NHL). However, the mechanisms that lead to AIDS-NHL have not been completely defined. A subset of B cells that is characterized by the secretion of IL10, as well as the expression of the programmed cell death ligand-1 (PD-L1/CD274), was recently described. These PD-L1+ B cells can exert regulatory function, including the dampening of T-cell activation, by interacting with the program cell death protein (PD1) on target cells. The role of PD-L1+ B cells in the development of AIDS-NHL has not been explored. We assessed B cell PD-L1 expression on B cells preceding AIDS-NHL diagnosis in a nested case-control study of HIV+ subjects who went on to develop AIDS-NHL, as well as HIV+ subjects who did not, using multi-color flow cytometry. Archival frozen viable PBMC were obtained from the UCLA Multicenter AIDS Cohort Study (MACS). It was seen that the number of CD19+CD24++CD38++and CD19+PD-L1+cells was significantly elevated in cases 1-4 years prior to AIDS-NHL diagnosis, compared to controls, raising the possibility that these cells may play a role in the etiology of AIDS-NHL. Interestingly, most PD-L1+ expression on CD19+ cells was seen on CD19+CD24++CD38++ cells. In addition, we showed that HIV can directly induce PD-L1 expression on B cells through interaction of virion-associated CD40L with CD40 on B cells
Pulse Fluoroscopy Radiation Reduction in a Pediatric Cardiac Catheterization Laboratory
ObjectiveTo determine if lower starting pulse fluoroscopy rates lead to lower overall radiation exposure without increasing complication rates or perceived procedure length or difficulty.SettingThe pediatric cardiac catheterization laboratory at University of Michigan Mott Children's Hospital.PatientsPediatric patients with congenital heart disease.Design/InterventionsWe performed a single‐center quality improvement study where the baseline pulse fluoroscopy rate was varied between cases during pediatric cardiac catheterization procedures.Outcome MeasuresIndirect and direct radiation exposure data were collected, and the perceived impact of the fluoroscopy rate and procedural complications was recorded. These outcomes were then compared among the different set pulse fluoroscopy rates.ResultsComparing pulse fluoroscopy rates of 15, 7.5, and 5 frames per second from 61 cases, there was a significant reduction in radiation exposure between 15 and 7.5 frames per second. There was no difference in perceived case difficulty, procedural length, or procedural complications regardless of starting pulse fluoroscopy rate.ConclusionsFor pediatric cardiac catheterizations, a starting pulse fluoroscopy rate of 7.5 frames per second exposes physicians and their patients to significantly less radiation with no impact on procedural difficulty or outcomes. This quality improvement study has resulted in a significant practice change in our pediatric cardiac catheterization laboratory, and 7.5 frames per second is now the default fluoroscopy rate.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111168/1/chd12197.pd
Willingness, preferred ways and potential barriers to use pre-exposure prophylaxis for HIV prevention among men who have sex with men in China
Objective To explore willingness and preferred ways to use HIV pre-exposure prophylaxis (PrEP), factors associated with willingness, and potential barriers to PrEP use among men who have sex with men (MSM) in Changsha, China. Design A cross-sectional survey was conducted from 25 June to 31 August 2019. Two hundred and fifty-five MSM were recruited from three community-based organisations (CBOs) in Changsha City. Willingness and potential barriers to use PrEP were examined using researcher-created scales. Univariate and multivariate logistic regression was used to analyse the factors associated with willingness to use PrEP. P values <0.05 were considered significant. Setting Three MSM inclusive CBOs in Changsha, Hunan Province, China. Participants 255 HIV-negative MSM were recruited through their CBOs with snowball sampling. Results Less than half of the participants (43.1%) had heard of PrEP and 15.3% were willing to use PrEP. The participants reported higher willingness to use event-driven PrEP (3.70±0.07) than daily PrEP (2.65±0.07). Higher self-rated risk and fear of contracting HIV (OR: 14.47, 95% CI 2.19 to 95.53), awareness of PrEP (OR: 4.20, 95% CI 1.64 to 10.73), sharing one's own sexual orientation with parents or siblings (OR: 2.52, 95% CI 1.54 to 7.20) and having a university education or above (OR:0.29, 95% CI 0.12 to 0.72) were associated with willingness to use PrEP. Only 12.2% of the sample was concerned about potential barriers to PrEP use. Conclusion Efforts to improve awareness and knowledge of PrEP, teach self-evaluation of HIV infection risk and provide social and emotional support for MSM are needed to scale up PrEP implementation in China. © Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Wendy Cross, Louisa Lam and Bixwajit Banik” is provided in this record*
Condom use consistency and associated factors among college student men who have sex with men from seven colleges in Changsha city : a cross-sectional survey
Background: College student men who have sex with men (MSM) are at high risk for HIV infection due to multiple social and behavioral factors. Consistent condom use is nationally advocated for HIV prevention. This study explored the sexual behaviors and factors associated with condom use consistency in the past six months among college student MSM from seven colleges in Hunan Province, China. Methods: A cross-sectional survey was conducted from September 2017 to March 2018. Condom use consistency, sexual behaviors, HIV testing performance, substance use, and alcohol consumption were examined using researcher-created questionnaires. Condom use self-efficacy and HIV-related knowledge were assessed using the Condom Use Self-Efficacy Scale and the unified National AIDS Sentinel Surveillance Questionnaire. Univariate and multivariate logistic regressions were used. P <0.05 was considered significant. Results: In the 214 respondents, the rate of consistent condom use was 56% (n = 119) during the past six months. Participants who were studying at first-tier universities (odds ratio [OR]: 2.522, 95% confidence interval [CI]: 1.255–5.067) and had higher scores for condom use self-efficacy (OR: 2.617, 95% CI: 1.462–4.685) were more likely to report consistent condom use than the others. The risk factor was having suspicious symptoms of sexually transmitted diseases (OR: 0.357, 95% CI: 0.163–0.780). Conclusion: Numerous students were at high risk of HIV infection with inconsistent condom use. Comprehensive and specific topics about safe sex education from parents and peers should be offered on campuses in China. © 2021 Wang et al
Novelty seeking and mental health in Chinese university students before, during, and after the COVID-19 pandemic lockdown: a longitudinal study
COVID-19 has created significant concern surrounding the impact of pandemic lockdown on mental health. While the pandemic lockdown can be distressing, times of crisis can also provide people with the opportunity to think divergently and explore different activities. Novelty seeking, where individuals explore novel and unfamiliarly stimuli and environments, may enhance the creativity of individuals to solve problems in a way that allows them to adjust their emotional responses to stressful situations. This study employs a longitudinal design to investigate changes in novelty seeking and mental health outcomes (namely, stress, anxiety, and depression) before, during, and after COVID-19 pandemic lockdown, among a group of students (final N = 173; Mage = 19.81; SDage = 0.98; 135 females and 38 males) from a university in southeast China. Participants were surveyed at three points: November, 2019 (prior to the COVID-19 pandemic); between February and March, 2020 (during the peak of the pandemic and intense lockdown in China); and between May and June, 2020 (after lockdown had been lifted in China). Cross-sectionally, correlation analysis indicated that greater novelty seeking was associated with lower levels of stress, anxiety, and depression at all three time points. Univariate latent curve modelling (LCM) indicated a growth trajectory in which novelty seeking increased over time and then remained high during the post-lockdown period. Stress, anxiety, and depression all showed V-shaped growth trajectories in which these variables decreased during lockdown, before increasing in the post-lockdown period. Multivariate LCM indicated the growth trajectory for novelty seeking was associated with the growth trajectories for stress, anxiety, and depression. This suggests that the observed decreases in stress, anxiety, and depression during the lockdown period may be attributable to the sample’s observed increase in novelty seeking. These findings are valuable in that they challenge the notion that lockdown measures are inherently detrimental to mental health. The findings indicate the important role of novelty seeking in responding to crises. It may be possible for future public health measures to incorporate the promotion of novelty seeking to help individuals’ respond to stressful situations and maintain good mental health in the face of crises
Mental health of Chinese people during the COVID-19 pandemic: associations with infection severity of region of residence and filial piety
This study aims to investigate mental health among Chinese people living in areas with differing levels of infection severity during the COVID-19 outbreak. It also assesses the association between reciprocal and authoritarian filial piety and mental health in times of crises. A sample of 1,201 Chinese participants was surveyed between April and June 2020. Wuhan city (where 23.4% of participants resided), Hubei province outside Wuhan (13.4% of participants), and elsewhere in China (63.1% of participants) were categorized into high, moderate, and low infection severity areas, respectively. The Depression, Anxiety, and Stress Scale’s severity cut-points were used to categorize participants. In the overall sample, 20.9, 34.2, and 29.0% of the participants showed elevated (mild to extremely severe) levels of stress, anxiety, and depression. Those in the highest infection severity group were significantly more likely to be categorized as having elevated levels of stress, anxiety, and depression. General linear modeling was performed on a composite mental distress variable (taking into account stress, anxiety, and depression scores). This model indicated that, even after adjusting for group differences in age, gender, education, and filial piety, the high infection severity group displayed more mental distress than the low infection severity groups. The model also found reciprocal filial piety to have a negative association with mental distress. Conversely, authoritarian filial piety was found to be unrelated to mental distress when controlling for the other variables in the model. No evidence was found for an interaction between either authoritarian or reciprocal filial piety and infection severity, which suggests that the negative association observed between reciprocal filial piety and mental distress was relatively consistent across the three infection severity groups. The findings suggest that future public health programs may integrate the promotion of filial piety as a strategy to help Chinese people maintain good mental health in the face of pandemic crises
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The HIV Genomic Incidence Assay Meets False Recency Rate and Mean Duration of Recency Infection Performance Standards.
HIV incidence is a primary metric for epidemic surveillance and prevention efficacy assessment. HIV incidence assay performance is evaluated via false recency rate (FRR) and mean duration of recent infection (MDRI). We conducted a meta-analysis of 438 incident and 305 chronic specimens' HIV envelope genes from a diverse global cohort. The genome similarity index (GSI) accurately characterized infection stage across diverse host and viral factors. All except one chronic specimen had GSIs below 0.67, yielding a FRR of 0.33 [0-0.98] %. We modeled the incidence assay biomarker dynamics with a logistic link function assuming individual variabilities in a Beta distribution. The GSI probability density function peaked close to 1 in early infection and 0 around two years post infection, yielding MDRI of 420 [361, 467] days. We tested the assay by newly sequencing 744 envelope genes from 59 specimens of 21 subjects who followed from HIV negative status. Both standardized residuals and Anderson-Darling tests showed that the test dataset was statistically consistent with the model biomarker dynamics. This is the first reported incidence assay meeting the optimal FRR and MDRI performance standards. Signatures of HIV gene diversification can allow precise cross-sectional surveillance with a desirable temporal range of incidence detection
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