Blood plasma separation in elevated dimension T-shaped microchannel

In recent years, microfluidic chips have proven ideal tools for biochemical analysis, which, however, demands a unique and compatible plasma separation scheme. Various research groups have established continuous flow separation methods in microfluidic devices; however, they have worked with relatively small dimension microchannels (similar to the blood cell diameter). The present work demonstrates separation of plasma by utilizing the hydrodynamic separation techniques in microchannels with size of the order of mm. The separation process exploits the phenomenon, which is very similar to that of plasma skimming explained under Zweifach-Fung bifurcation law. The present experiments demonstrates for, the first time, that applicability of the Zweifach-Fung bifurcation law can be extended to dimensions much higher than the suspended particle size. The T-microchannel device (comprising perpendicularly connected blood and plasma channels) were micro-fabricated using conventional PDMS micro-molding techniques. Three variables (feed hematocrit, main channel width, and flow rate distributions) were identified as the important parameters which define the device’s efficiency for the blood plasma separation. A plasma separation efficiency of 99.7 % was achieved at a high flow ratio. Novel concepts of 2-stage or multiple plasma channel designs are also proposed to yield high separation efficiency with undiluted blood. The possible underlying principle causing plasma separation (viz. aggregation and shear thinning) are investigated in detail as part of this work. The results are significant because they show nearly 100 % separations in microchannels which are much easier to fabricate than previously designed devices.     

Maximizing the Value of Mobile Health Monitoring by Avoiding Redundant Patient Reports: Prediction of Depression-Related Symptoms and Adherence Problems in Automated Health Assessment Services

Background

Interactive voice response (IVR) calls enhance health systems’ ability to identify health risk factors, thereby enabling targeted clinical follow-up. However, redundant assessments may increase patient dropout and represent a lost opportunity to collect more clinically useful data.

Objective

We determined the extent to which previous IVR assessments predicted subsequent responses among patients with depression diagnoses, potentially obviating the need to repeatedly collect the same information. We also evaluated whether frequent (ie, weekly) IVR assessment attempts were significantly more predictive of patients’ subsequent reports than information collected biweekly or monthly.

Methods

Using data from 1050 IVR assessments for 208 patients with depression diagnoses, we examined the predictability of four IVR-reported outcomes: moderate/severe depressive symptoms (score ≥10 on the PHQ-9), fair/poor general health, poor antidepressant adherence, and days in bed due to poor mental health. We used logistic models with training and test samples to predict patients’ IVR responses based on their five most recent weekly, biweekly, and monthly assessment attempts. The marginal benefit of more frequent assessments was evaluated based on Receiver Operator Characteristic (ROC) curves and statistical comparisons of the area under the curves (AUC).

Results

Patients’ reports about their depressive symptoms and perceived health status were highly predictable based on prior assessment responses. For models predicting moderate/severe depression, the AUC was 0.91 (95% CI 0.89-0.93) when assuming weekly assessment attempts and only slightly less when assuming biweekly assessments (AUC: 0.89; CI 0.87-0.91) or monthly attempts (AUC: 0.89; CI 0.86-0.91). The AUC for models predicting reports of fair/poor health status was similar when weekly assessments were compared with those occurring biweekly (P value for the difference=.11) or monthly (P=.81). Reports of medication adherence problems and days in bed were somewhat less predictable but also showed small differences between assessments attempted weekly, biweekly, and monthly.

Conclusions

The technical feasibility of gathering high frequency health data via IVR may in some instances exceed the clinical benefit of doing so. Predictive analytics could make data gathering more efficient with negligible loss in effectiveness. In particular, weekly or biweekly depressive symptom reports may provide little marginal information regarding how the person is doing relative to collecting that information monthly. The next generation of automated health assessment services should use data mining techniques to avoid redundant assessments and should gather data at the frequency that maximizes the value of the information collected.     

Comparative forensic analysis of reverse root canal filing and conventional method for DNA isolation from extracted teeth under different environmental conditions: A prospective study

The grinding of a whole tooth specimen has been considered the conventional method to extract genomic deoxyribonucleic acid (DNA) in forensic science. However, we have tried the less destructive reverse root canal filing (RRCF) method without disturbing the morphology of the tooth to achieve competent amplifiable DNA. A total of 27 pairs of bilateral intact extracted teeth from the same subject were used in three different simulated environmental conditions for the respective RRCF and conventional methods: (a) soil burial for six months, (b) incineration at 200º C for four minutes, and (c) immersion in water for two months. Qualitative agarose gel electrophoresis assessment and downstream amplification were performed. The results showed significantly higher mean DNA concentration for the RRCF method in all three environmental conditions (p value = 0.008) in comparison to the conventional method. However, comparable qualitative results were found in both methods for the mean DNA concentration for incinerated (159.49 ng/ml), soil (119.52 ng/ml), and water (108.60 ng/ml) samples. It was concluded that the RRCF method is better quantitively (ng/ml) and comparable in terms of quality with respect to the conventional method, with the added advantage of preservation of the tooth morphology.     

Clinical outcome of living donor kidney transplantation across simultaneous ABO and HLA incompatibility: Single center experience of first ten cases

Background and aimsPreconditioning using different protocols has been tested to prevent antibody mediated rejection (ABMR) individually for ABO and HLA incompatibility. However, simultaneous presence of both barriers is still less explored. The aim of this study was to report outcomes of institutional desensitization protocol in renal transplant recipients with simultaneous ABO and HLA incompatibility.Materials and methodsThis was a retrospective study conducted from October 2015 to December 2018. All patients with a clinical diagnosis of dialysis dependent chronic kidney disease (CKD), who were prospective coexistent HLA and ABO incompatible renal transplant recipients were included in the study. Patients were followed up and graft function and patient survival was assessed at 1 y from the date of transplant.ResultsMedian and mode baseline anti-A titers were 64, while median and mode baseline anti-B titers were 256. All recipients were discharged by tenth postoperative day. None of the patients had any bleeding complications. Post transplant infection rate was found to be 20 %. A total of 54 therapeutic plasma exchange (TPE) procedures were performed before transplant and 8 were performed after transplant. Graft survival and patient survival was 100 % at 3, 6, 9, and 12 months. Range and mean follow-up period was 15–42 months and 23 months respectively. Mean glomerular filtration rate (GFR) at 1 y using the CKD-EPI equation was 85.25 ± 13.76 mL/min. Biopsy proven ABMR was observed in one case only which was managed with TPE and immunosuppression.ConclusionSimultaneous ABO and HLA incompatibility in renal transplant recipients can be managed successfully with adequate preconditioning and careful monitoring.     

Distal radial artery (snuffbox) access for carotid artery stenting – Technical pearls and procedural set-up

PurposeTo report use of distal radial artery (dRA) access for carotid artery stenting (CAS) and to discuss procedural setup and technical considerations for a successful intervention.MethodsA retrospective review of our prospective neurointerventional database of CAS was conducted between May 2019 and March 2020. All CAS cases via dRA in the anatomical snuffbox were identified. Patient demographics, clinical information, procedural and radiographic data was collected.Results22 CAS procedures in 20 patients via dRA were identified. Patients’ mean age was 69.4 years (range 53–87 years). 3 patients were female. Mean radial artery diameter was 2.1 mm (range 1.6–2.8 mm). dRA access was achieved in all cases. Conversion to femoral access was required in 2 cases (9.1%) due to persistent radial artery vasospasm resulting in patient discomfort despite multiple additional doses of intraarterial vasodilators and added intravenous sedation as well as tortuous vessel anatomy and limited support of the catheters in a type 3 aortic arch for left CAS.ConclusionOur preliminary experience with dRA access for CAS suggests this approach to be feasible and safe for patients. Technical considerations are important and preprocedural planning is necessary for a successful intervention. Catheter systems and devices specifically designed for radial access are needed to enable more interventionalists to safely perform neurointerventional procedures via wrist access.     

Lessons learnt from an obstetric and neonatal emergency simulation program in India

BackgroundCombined obstetric and neonatal emergency simulation based training is gaining popularity in healthcare settings. Methods: In this qualitative study, through semi-structured one to one interviews, we evaluated participant attitudes, perceptions of retention of learning, and application to clinical practice one year after a simulation workshop. Audio recordings of interviews were transcribed, collated and subjected to thematic analysis. Results: Five major themes were identified through the thematic analysis: comparing simulation to clinical practice; learning and working in teams; thinking retention and sustainability; relating relevance of simulation based education to roles; and managing leadership. Conclusions: Participants’ acknowledgement of training being relevant to their routine practice, and keenness to learn management of complicated births highlighted the sustained impact of obstetric and neonatal emergency simulation training.     

Oligo-glycerol based non-ionic amphiphilic nanocarriers for lipase mediated controlled drug release

A new class of non-ionic amphiphiles is synthesized using a diaryl derivative of diglycerol as a central core and functionalizing it with long alkyl chains (C-12/C-15) and monomethoxy PEG moiety (M_n: 350/550) by following a chemo-enzymatic approach. The aggregation behavior of the amphiphiles in aqueous medium is studied by using dynamic light scattering (DLS) and fluorescence spectroscopy, whereas the size and morphology of the aggregates are studied by transmission electron microscopy (TEM). A hydrophobic dye, Nile red and a hydrophobic drug, nimodipine, are used to demonstrate the nano-carrier capability of these non-ionic amphiphilic systems and the results are compared with amphiphilic analogues obtained from the triaryl derivatives of triglycerol. The in vitro controlled release of the encapsulated dye is successfully carried out in the presence of immobilized Candida antarctica lipase (Novozym 435). Furthermore, cytotoxicity data is also collected which suggests that the amphiphiles are suitable for biomedical applications.

A new series of oligo-glycerol based amphiphiles have been synthesized for drug delivery.     

Synergistic effect of Ni–Ag–rutile TiO2 ternary nanocomposite for efficient visible-light-driven photocatalytic activity

P25 comprising of mixed anatase and rutile phases is known to be highly photocatalytically active compared to the individual phases. Using a facile wet chemical method, we demonstrate a ternary nanocomposite consisting of Ni and Ag nanoparticles, decorated on the surface of XTiO₂ (X: P25, rutile (R)) as an efficient visible-light-driven photocatalyst. Contrary to the current perspective, RTiO₂-based Ni–Ag–RTiO₂ shows the highest activity with the H₂ evolution rate of ∼86 μmol g⁻¹ W⁻¹ h⁻¹@535 nm. Together with quantitative assessment of active Ni, Ag and XTiO₂ in these ternary systems using high energy synchrotron X-ray diffraction, transmission electron microscopy coupled energy dispersive spectroscopy mapping evidences the metal to semiconductor contact via Ag. The robust photocatalytic activity is attributed to the improved visible light absorption, as noted by the observed band edge of ∼2.67 eV corroborating well with the occurrence of Ti³⁺ in Ti 2p XPS. The effective charge separation due to intimate contact between Ni and RTiO₂via Ag is further evidenced by the plasmon loss peak in Ag 3d XPS. Moreover, density functional theory calculations revealed enhanced adsorption of H₂ on Ti₈O₁₆ clusters when both Ag and Ni are simultaneously present, owing to the hybridization of the metal atoms with d orbitals of Ti and p orbitals of O leading to enhanced bonding characteristics, as substantiated by the density of states. Additionally, the variation in the electronegativity in Bader charge analysis indicates the possibility of hydrogen evolution at the Ni sites, in agreement with the experimental observations.

Robust photocatalytic activity of Ni–Ag–RTiO₂ is attributed to the improved visible light absorption and effective charge separation due to intimate contact between Ni and RTiO₂via Ag, as evidenced by Ti³⁺ in Ti 2p XPS and energy dispersive mapping.