The behaviour of nearly neutrally-buoyant suspensions has been studied experimentally, using a concentric-cylinder rheometer. The effect on the suspension viscosity of: (i) solid fraction, (ii) ...diameter of the solid, spherical particles, (iii) viscosity of the suspending liquid, and (iv) shear rate has been determined experimentally, where all suspensions have been created using the same particulate and liquid materials. The suspension behaviour can well be described by the Ostwald-deWaele model, i.e. a power-law relation between shear stress and shear rate. For low solid fractions, the behaviour is nearly Newtonian, while for larger solid fractions shear thinning behaviour is observed. The relative viscosity, i.e. the ratio between suspension and liquid viscosities, is a rapidly increasing function of solid fraction. For suspensions based on a liquid with high viscosity, the effect of the particle diameter is small, while for those with a low liquid viscosity, the suspension viscosity decreases weakly with increasing particle diameter. The relative viscosity is higher for systems based on a liquid with low viscosity, in comparison with systems with a high liquid viscosity. The current investigation shows that commonly used relations for the relative viscosity of suspensions, that only include solid fraction and a maximum solid fraction, are not generally valid.
It is somewhat ironic that although youth today are saturated in media, no standardized instrument exists to measure individual's exposure to specific media content. Therefore, we developed and ...validated a scale to measure both the frequency and content of adolescents' media exposure which measures media exposure regardless of media channel: the Content-based Media Exposure Scale (C-ME). The C-ME includes 17 items that assess exposure to antisocial (8 items) and neutral (9 items) media content. The factor structure was investigated in three independent samples (N = 892; N = 748; N = 524). Model fit indices like CFA's and RMSEA showed good fit, for both types of content, and predictive and discriminant validity was assessed. Exposure to antisocial media content positively correlated with sensation seeking, trait aggressiveness, violent media use, and general media use. The C-ME proves a reliable and easy to use instrument that measures media exposure in today's (new) media landscape.
•The C-ME measures both the content and frequency of individual media exposure.•The C-ME covers all media channels, today often converging through computer screens.•The C-ME is a valid, reliable and easy to use instrument in all research designs.•The C-ME measures differential exposure to a wide variety of media content.•The C-ME allows for standardization and comparisons across studies.
The present research developed a measure for exposure to both antisocial and prosocial media content by revising and extending a previous Content-based Media Exposure Scale (C-ME). The validity and ...reliability of the C-ME2 was tested in two independent samples (N = 678), among young adults (Study 1) and adolescents (Study 2). Results of Confirmatory Factor Analyses showed good fit, in both studies, for both antisocial and prosocial dimensions of media content, and for both males and females. Furthermore, the C-ME2 explains unique variance beyond previous measures of violent and general media exposure. Evidence is presented of reliability, discriminant and predictive validity of the C-ME2, measuring both frequency and exposure to specific content of media. The C-ME2 covers all media platforms, is easy to use in all research designs, and allows for standardization and systematic comparisons across studies.
Background
The mental health of dialysis patients during the COVID-19 pandemic may have been modulated by dialysis modality. Studies comparing mental health of in-center hemodialysis and peritoneal ...dialysis patients during the first 2 years of the pandemic are lacking.
Methods
We conducted repeated cross-sectional and multivariable regression analyses to compare the mental health of in-center hemodialysis and peritoneal dialysis patients from March 2019 until August 2021 using data from the Dutch nOcturnal and hoME dialysis Study To Improve Clinical Outcomes. The study period was divided into one pre-pandemic and six 3-month pandemic periods (period 1–period 6). Mental health was assessed with the Mental Component Summary score of the 12-item Short Form health survey and mental symptoms of the Dialysis Symptom Index.
Results
We included 1274 patients (968 on in-center hemodialysis and 306 on peritoneal dialysis). Mental Component Summary scores did not differ between in-center hemodialysis and peritoneal dialysis patients. In contrast, in-center hemodialysis patients more often reported nervousness during period 3 (27% vs 15%,
P
= 0.04), irritability and anxiety during period 3 (31% vs 18%,
P
= 0.03, 26% vs. 9%,
P
= 0.002, respectively) and period 4 (34% vs 22%,
P
= 0.04, 22% vs 11%,
P
= 0.03, respectively), and sadness in period 4 (38% vs 26%,
P
= 0.04) and period 5 (37% vs 22%,
P
= 0.009). Dialysis modality was independently associated with mental symptoms.
Conclusions
In-center hemodialysis patients more often experienced mental symptoms compared to peritoneal dialysis patients from September 2020 to June 2021, which corresponds to the second lockdown of the COVID-19 pandemic. Mental health-related quality-of-life did not differ between in-center hemodialysis and peritoneal dialysis patients.
Trial registration number
Netherlands Trial Register NL6519, date of registration: 22 August, 2017.
Graphical abstract
Chronic pain is a recognized complication of surgery, and it has been hypothesized that regional anesthesia might reduce the risk of development of chronic pain after upper extremity surgery.
A ...systematic literature review was performed to assess whether in patients undergoing elective upper extremity surgery (P), regional anesthesia (I), compared to general anesthesia (C), would result in lower long-term (>3 months) postoperative pain intensity (O). We included randomized and nonrandomized controlled trials (RCTs). Our primary outcome was numerical rating score or visual analogue scale for pain, at >3 months postoperatively. The Embase, Medline ALL, Web of Science Core Collections, Cochrane Central Register of Controlled Trials, and Google Scholar databases were searched for all reports assessing pain at >3 months after upper extremity surgery under general versus regional anesthesia. Secondary outcomes were: opioid prescription filling, complex regional pain syndrome (CRPS) incidence, the Mayo Wrist Score (MWS), and scores on the Disability of the Arm, Shoulder and Hand (DASH) questionnaire. Quality (or certainty) of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE). Risk-of-bias was assessed using the Cochrane tool for randomized trials (RoB 2.0) and nonrandomized trials (ROBINS-I).
This review included 14 studies, comprising 7 RCTs and 7 nonrandomized studies. Six of the 7 studies (4 RCTs, N = 273; 2 nonrandomized studies, N = 305) using a pain score, our primary outcome, report comparable long-term postoperative pain scores after regional and general anesthesia. Six of the 7 studies using our secondary outcomes report comparable long-term outcomes in terms of opioid prescription filling (2 retrospective cohort studies RCSs, N = 89,256), CRPS incidence (1 RCT, N = 301), MWS (1 RCT and 1 RCS, N = 215), and DASH score (1 RCT, N = 36). Comparable outcomes were reported in all 7 RCTs (N = 778) and in 5 of the 7 nonrandomized studies, comprising 5 RCSs (N = 89,608). Two prospective observational studies (POSTs), comprising 279 patients, report a statistically significant difference in outcomes, with less pain and better DASH scores after brachial plexus anesthesia. All 14 studies provided moderate to very low certainty evidence, and there was a serious risk of bias due to confounding bias in 5 of the 7 nonrandomized studies (N = 631).
The results of this review indicate that upper extremity regional anesthesia, compared to general anesthesia, is unlikely to change pain intensity at >3 months postoperatively.
To evaluate whether a third vaccination shows an added effect on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) T-cell responses in patients with multiple sclerosis treated with ...ocrelizumab or fingolimod.
This is a substudy of a prospective multicenter study on SARS-CoV-2 vaccination in patients with immune-mediated diseases. Patients with MS treated with ocrelizumab, fingolimod, and no disease-modifying therapies and healthy controls were included. The number of interferon (IFN)-γ secreting SARS-CoV-2-specific T cells at multiple time points before and after 3 SARS-CoV-2 vaccinations were evaluated.
In ocrelizumab-treated patients (N = 24), IFN-γ-producing SARS-CoV-2-specific T-cell responses were induced after 2 vaccinations with median levels comparable to healthy controls (N = 12) and patients with MS without disease-modifying therapies (N = 10). A third vaccination in ocrelizumab-treated patients (N = 8) boosted T-cell responses that had declined after the second vaccination, but did not lead to higher overall T-cell responses as compared to immediately after a second vaccination. In fingolimod-treated patients, no SARS-CoV-2-specific T cells were detected after second (N = 12) and third (N = 9) vaccinations.
In ocrelizumab-treated patients with MS, a third SARS-CoV-2 vaccination had no additive effect on the maximal T-cell response but did induce a boost response. In fingolimod-treated patients, no T-cell responses could be detected following both a second and third SARS-CoV-2 vaccination.
SARS-CoV-2-specific CD8+ T cells recognize conserved viral peptides and in the absence of cross-reactive antibodies form an important line of protection against emerging viral variants as they ...ameliorate disease severity. SARS-CoV-2 mRNA vaccines induce robust spike-specific antibody and T cell responses in healthy individuals, but their effectiveness in patients with chronic immune-mediated inflammatory disorders (IMIDs) is less well defined. These patients are often treated with systemic immunosuppressants, which may negatively affect vaccine-induced immunity. Indeed, TNF inhibitor (TNFi)-treated inflammatory bowel disease (IBD) patients display reduced ability to maintain SARS-CoV-2 antibody responses post-vaccination, yet the effects on CD8+ T cells remain unclear.
Here, we analyzed the impact of IBD and TNFi treatment on mRNA-1273 vaccine-induced CD8+ T cell responses compared to healthy controls in SARS-CoV-2 experienced and inexperienced patients. CD8+ T cells were analyzed for their ability to recognize 32 SARS-CoV-2-specific epitopes, restricted by 10 common HLA class I allotypes using heterotetramer combinatorial coding. This strategy allowed in-depth ex vivo profiling of the vaccine-induced CD8+ T cell responses using phenotypic and activation markers.
mRNA vaccination of TNFi-treated and untreated IBD patients induced robust spike-specific CD8+ T cell responses with a predominant central memory and activated phenotype, comparable to those in healthy controls. Prominent non-spike-specific CD8+ T cell responses were observed in SARS-CoV-2 experienced donors prior to vaccination. Non-spike-specific CD8+ T cells persisted and spike-specific CD8+ T cells notably expanded after vaccination in these patient cohorts. Our data demonstrate that regardless of TNFi treatment or prior SARS-CoV-2 infection, IBD patients benefit from vaccination by inducing a robust spike-specific CD8+ T cell response.
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•SARS-CoV-2 vaccinated IBD patients induce broad and robust CD8+ T cell responses.•TNF inhibitor treatment did not affect SARS-CoV-2-specific CD8+ T cell populations.•Vaccine-induced CD8+ T cells express dominant memory and activated phenotypes.•SARS-CoV-2-specific CD8+ T cell responses in IBD patients were similar to controls.
Kidney transplant recipients (KTRs) were advised to tightly adhere to government recommendations to curb the spread of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) because of a high ...risk of morbidity and mortality and decreased immunogenicity after vaccination. The aim of this study was to analyse the change in adherence to preventive measures after vaccination and awareness of antibody response, and to evaluate its effectiveness.
In this large-scale, national questionnaire study, questionnaires were sent to 3531 KTRs enrolled in the Dutch RECOVAC studies, retrospectively asking for adherence to nine preventive measures on a 5-point Likert scale before and after SARS-CoV-2 vaccination and after awareness of antibody response. Blood samples were collected 28 days after the second vaccination. Antibody response was categorised as non-responder (≤50 BAU/mL), low-responder (>50 ≤ 300 BAU/mL) or high-responder (>300 BAU/mL), and shared with participants as a correlate of protection. Participants of whom demographics on sex and age, blood samples and completed questionnaires were available, were included. Our study took place between February 2021 and January 2022. The primary outcome of adherence before and after vaccination was assessed between August and October 2021 and compared via the Wilcoxon signed rank sum test. Logistic regression analysis was performed to estimate the association between antibody response and non-adherence, and adherence on acquiring SARS-CoV-2 infection. This study is registered at ClinicalTrials.gov (NCT04841785).
In 2939 KTRs (83%) who completed the first questionnaire on adherence to preventive measures, adherence was higher before than after vaccination (4.56, IQR 4.11–4.78 and 4.22, IQR 3.67–4.67, p < 0.001). Adherence after awareness of antibody response was analysed in 2399 KTRs (82%) of whom also blood samples were available, containing 949 non-responders, 500 low-responders and 950 high-responders. Compared to non-responders, low- and high-responders reported higher non-adherence. Higher adherence was associated with lower infection rates before and after vaccination (OR 0.67 0.51–0.91, p = 0.008 and OR 0.48 0.28–0.86, p = 0.010).
Adherence decreased after SARS-CoV-2 vaccination and in KTRs who were aware of a subsequent antibody response compared with those without. Preventive measures in this vulnerable group seem to be effective, regardless of vaccination status. This study starts a debate on sharing antibody results with the patient and future studies should elucidate whether decreased adherence in antibody responders is justified, also in view of future pandemics.
The Netherlands Organization for Health Research and Development and the Dutch Kidney Foundation.
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