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Background: Prolonged warm ischemia time (WIT) in kidney transplantation is associated with numerous adverse outcomes including delayed graft function and decreased patient and graft survival. Circumventing WIT lies in maintaining renal hypothermia and efficiently performing the vascular anastomosis during this portion of the procedure. Although numerous methods of intra-operative renal cooling have been proposed, most suffer from practical limitations, and none have been widely adopted. Herein we describe a novel device specifically designed to maintain renal hypothermia during kidney transplant surgery. Methods: Aluminum tubing was organized in a serpentine pattern to create a malleable, form-fitting cooling jacket to manipulate renal allografts during transplant surgery. Adult porcine kidneys were used to test the device with 4°C saline as coolant. Kidneys were placed at 24°C; surface and core temperatures were monitored using implanted thermocouples. Anastomosis of porcine kidney vessels to GORE-TEX® vascular grafts in an ex-vivo operative field was performed to assess the functionality of the device. Results: The device maintained surface and core graft temperatures of ≤5°C after 60 minutes of WIT. Furthermore, the device provided hands-free retraction and support for the allograft. We found that ex-vivo anastomosis testing was enhanced by the presence of the cooling jacket. Conclusions: This proof-of-concept study demonstrated that our novel device is a practical tool for renal transplantation and can maintain sufficiently cool graft temperatures to mitigate WIT in an ex-vivo setting. This device is the first of its kind and has the potential to improve kidney transplant outcomes by eliminating WIT during graft implantation. [ABSTRACT FROM AUTHOR]

Progressive multifocal leukoencephalopathy (PML) is a rare disease of the central nervous system caused by opportunistic infection with JC virus. It presents in patients who are immunocompromised, and diagnosis is made by correlating clinical findings and radiological changes with the detection of JC virus in cerebrospinal fluid. Rarely, a brain biopsy is needed. A 72 year old with high grade B-cell lymphoma developed right arm weakness and limb ataxia shortly after his diagnosis. CNS involvement was excluded with a normal CT head, MRI brain/spine, and CSF examination. A paraneoplastic cause was suspected, and he received 5 cycles of Rituximab-containing chemotherapy to a complete metabolic remission. His neurology evolved during treatment despite serial MRI and CSF examination remaining normal. CSF and serum were both negative for JC virus by PCR. Following completion of chemotherapy, he deteriorated acutely with seizures and personality changes. It was only at this point that a repeat MRI showed new multiple scattered ring enhancing lesions within both cerebral hemispheres. The patient underwent a brain biopsy confirming JC virus positive-PML by immunohistochemistry and passed away one month later. This case illustrates the diagnostic challenges associated with PML and had several atypical features which led to diagnostic delay, specifically the onset of symptoms before starting immunochemotherapy, and the lack of radiological change despite evolving neurology. The eventual MRI abnormalities were not altogether classical for PML which, coupled with the JC-negativity in CSF and serum, meant a brain biopsy was required to reach the diagnosis. [ABSTRACT FROM AUTHOR]

In this work, optimal control theory was used to design efficient excitation schemes in highly conductive materials, where both the radio frequency field strength and phase vary as a function of penetration depth. A pulse was designed to achieve phase alignment between signals at different depths within the conductor and thus to obtain higher signals from that region. In addition, an efficient suppression pulse was designed by insuring mutual suppression between the signals from various depths in the sample. The performance of the new approach was demonstrated experimentally for a bulk lithium sample for the excitation problem and for a biphasic metal/liquid sample for the selective suppression pulse. [ABSTRACT FROM AUTHOR]

Purpose: We performed a systematic review and meta-analysis of the literature to evaluate the efficacy of the routine use of tranexamic acid (TXA) during percutaneous nephrolithotomy (PCNL). Methods: This systematic review was conducted following the updated reporting guidelines from PRISMA 2020. Results: In total, 275 titles and abstracts were reviewed, of which 20 were screened to be eligible for full text review. Of these 20 articles, 11 were selected for inclusion after full article evaluations. Seven of these 11 studies were seen as having a low risk of bias with a Jadad score of ≥3. These studies were included for data extraction. Once data were extracted, 964 patients were included. The primary outcome, blood transfusion rate, showed significant reduction with a ratio for transfusion rate of 0.34 [95% confidence interval (CI) (0.19 to 0.61), z = 3.61, p = 0.0003]. Mean hemoglobin (Hgb) drop and operative time were both shown to be reduced with the use of TXA. The mean difference for Hgb drop was −0.86 [95% CI (−1.26 to −0.46), z = 4.23, p < 0.0001]. Reduction in operative time showed a mean difference of −8.45 minutes [95% CI (−15.04 to −1.86), z = 2.51, p = 0.01]. Stone clearance was not shown to differ significantly between experimental and control groups, with a risk ratio of 1.28 [95% CI (0.89 to 1.84), z = 1.31, p = 0.19]. Conclusions: This meta-analysis revealed that the routine use of TXA at time of PCNL reduces the rates of blood transfusion, mean Hgb drop, and operative time. With the low cost of TXA and strong safety profile, stronger consideration should be given to the routine use of TXA during PCNL by endoscopic surgeons. [ABSTRACT FROM AUTHOR]

Background: Frequent pages can disrupt workflow, interrupt patient care, and may contribute to physician burnout. We hypothesized that paging volumes followed consistent temporal trends, regardless of the medical or surgical service, reflecting systems based issues present in our hospitals.Methods: A retrospective review of the hospital paging systems for 4 services at The Ottawa Hospital was performed. Resident paging data from April 1 to July 31, 2018 were collected for services with a single primary pager number including orthopaedic surgery, general surgery, neurology, and neurosurgery. Trends in paging volume during the 4-month period were examined. Variables examined included the location of origin of the page (emergency room vs. inpatient unit), and day/time of the page.Results: During the study period, 25,797 pages were received by the 4 services, averaging 211 (± Standard Deviation (SD) 12) pages per day. 19,371 (75%) pages were from in-patient hospital units, while 6426 (24%) were pages from the emergency room. The median interval between pages across all specialties was 22:30 min. Emergency room pages peaked between 16:30 and 20:00, while in-patient units peaked between 17:30 and 18:30.Conclusions: Each service experienced frequent paging with similar patterns of marked increases at specific times. This study identifies areas for future study about what the factors are that contribute to the paging patterns observed. [ABSTRACT FROM AUTHOR]

We experimentally investigate the dynamics of particles constituting grain boundaries in a two-dimensional colloidal crystal, using video-microscopy. A clear plateau in the mean square displacement of the grain boundary particles is found, followed by an upswing indicative of cage breaking. The van Hove correlation functions and the non-Gaussian parameter show that grain boundary particle dynamics are highly heterogeneous. Furthermore, we identified clusters of cooperatively moving particles and analyzed the time-dependence of the weight-averaged mean cluster size. We find good correlation between the behavior of the mean square displacement, and the time dependence of the non-Gaussian parameter and the cluster size, as also reported for various supercooled systems. Our results therefore provide experimental support for the similarity between particle dynamics in grain boundaries and in supercooled liquids as suggested by recent computer simulations. [ABSTRACT FROM AUTHOR]

In vivo Nuclear Magnetic Resonance (NMR) spectroscopy has great potential to interpret the biochemical response of organisms to their environment, thus making it an essential tool in understanding toxic mechanisms. However, magnetic susceptibility distortions lead to 1D NMR spectra of living organisms with lines that are too broad to identify and quantify metabolites, necessitating the use of 2D 1H–13C Heteronuclear Single Quantum Coherence (HSQC) as a primary tool. While quantitative 2D HSQC is well established, to our knowledge it has yet to be applied in vivo. This study represents a simple pilot study that compares two of the most popular quantitative 2D HSQC approaches to determine if quantitative results can be directly obtained in vivo in isotopically enriched Daphnia magna (water flea). The results show the perfect-HSQC experiment performs very well in vivo, but the decoupling scheme used is critical for accurate quantitation. An improved decoupling approach derived using optimal control theory is presented here that improves the accuracy of metabolite concentrations that can be extracted in vivo down to micromolar concentrations. When combined with 2D Electronic Reference To access In vivo Concentrations (ERETIC) protocols, the protocol allows for the direct extraction of in vivo metabolite concentrations without the use of internal standards that can be detrimental to living organisms. Extracting absolute metabolic concentrations in vivo is an important first step and should, for example, be important for the parameterization as well as the validation of metabolic flux models in the future. [ABSTRACT FROM AUTHOR]

Background: Misdiagnosis, either over- or underdiagnosis, exposes older patients to increased risk of inappropriate or omitted investigations and treatments, psychological distress, and financial burden. Objective: To evaluate the frequency and nature of diagnostic errors in 16 conditions prevalent in older patients by undertaking a systematic literature review. Data sources and study selection: Cohort studies, cross-sectional studies, or systematic reviews of such studies published in Medline between September 1993 and May 2014 were searched using key search terms of "diagnostic error", "misdiagnosis", "accuracy", "validity", or "diagnosis" and terms relating to each disease. Data synthesis: A total of 938 articles were retrieved. Diagnostic error rates of .10% for both over- and underdiagnosis were seen in chronic obstructive pulmonary disease, dementia, Parkinson's disease, heart failure, stroke/transient ischemic attack, and acute myocardial infarction. Diabetes was overdiagnosed in,5% of cases. Conclusion: Over- and underdiagnosis are common in older patients. Explanations for overdiagnosis include subjective diagnostic criteria and the use of criteria not validated in older patients. Underdiagnosis was associated with long preclinical phases of disease or lack of sensitive diagnostic criteria. Factors that predispose to misdiagnosis in older patients must be emphasized in education and clinical guidelines. [ABSTRACT FROM AUTHOR]

Accurate prediction of the saturation dependence of different modes of transport in porous media, such as those due to conductivity, air permeability, and diffusion, is of broad interest in engineering and natural resources management. Most current predictions use a "bundle of capillary tubes" concept, which, despite its widespread use, is a severely distorted idealization of natural porous media. In contrast, percolation theory provides a reliable and powerful means to model interconnectivity of disordered networks and porous materials. In this study, we invoke scaling concepts from percolation theory and effective medium theory to predict the saturation dependence of modes of transport - hydraulic and electrical conductivity, air permeability, and gas diffusion - in two disturbed soils. Universal scaling from percolation theory predicts the saturation dependence of air permeability and gas diffusion accurately, even when the percolation threshold for airflow is estimated from the porosity. We also find that the non-universal scaling obtained from the critical path analysis (CPA) of percolation theory can make excellent predictions of hydraulic and electrical conductivity under partially saturated conditions. [ABSTRACT FROM AUTHOR]

Ultra-high-field NMR spectroscopy requires an increased bandwidth for heteronuclear decoupling, especially in biomolecular NMR applications. Composite pulse decoupling cannot provide sufficient bandwidth at practical power levels, and adiabatic pulse decoupling with sufficient bandwidth is compromised by sideband artifacts. A novel low-power, broadband heteronuclear decoupling pulse is presented that generates minimal, ultra-low sidebands. The pulse was derived using optimal control theory and represents a new generation of decoupling pulses free from the constraints of periodic and cyclic sequences. In comparison to currently available state-of-the-art methods this novel pulse provides greatly improved decoupling performance that satisfies the demands of high-field biomolecular NMR spectroscopy. [ABSTRACT FROM AUTHOR]

Ultra-high-field NMR spectroscopy requires an increased bandwidth for heteronuclear decoupling, especially in biomolecular NMR applications. Composite pulse decoupling cannot provide sufficient bandwidth at practical power levels, and adiabatic pulse decoupling with sufficient bandwidth is compromised by sideband artifacts. A novel low-power, broadband heteronuclear decoupling pulse is presented that generates minimal, ultra-low sidebands. The pulse was derived using optimal control theory and represents a new generation of decoupling pulses free from the constraints of periodic and cyclic sequences. In comparison to currently available state-of-the-art methods this novel pulse provides greatly improved decoupling performance that satisfies the demands of high-field biomolecular NMR spectroscopy. [ABSTRACT FROM AUTHOR]

Tortuosity is a property of porous media that is invoked and used in the literature on hydrology, soil science, physics, and engineering. It has been defined in a variety of ways, one of which is a purely geometrical concept. In this study, we focused on the geometrical tortuosity and developed a model based on percolation theory and the finite-size scaling approach. Our result, developed for porous media of any saturation, expresses the tortuosity as a powerlaw function of the water content, the critical water content, and the system size. The model parameters include the fractal dimension of either the backbone (the flow-carrying part of porous media) or the optimal path (for crossing the system between two opposite faces), which have clear physical meaning. The results may be combined with power laws, which percolation theory provides for the hydraulic or electrical conductivity, to develop the appropriate form that expresses the connectivity as a function of the water content of a pore space. Comparison with numerical simulations and experiments reported in the literature indicated that the model estimates the tortuosity accurately. Our model and results leads us to conclude that pore connectivity and tortuosity should be treated as two distinct properties and that significant uncertainty in results for the saturation dependence of the hydraulic conductivity is traceable to the confusion that mixes the two as a single concept. [ABSTRACT FROM AUTHOR]

Abstand zwischen Spins: Ein neuer frequenzselektiver Breitband ‐ Inversionspuls wurde für die gepulste Elektron ‐ Elektron ‐ Doppelresonanz(PELDOR) ‐ Spektroskopie entwickelt, mit der Abstandsverteilungen zwischen zwei oder mehr paramagnetischen Zentren im Abstand von 2 – 10 nm bestimmt werden können. Die PELDOR ‐ Modulationstiefe kann durch den Wechsel vom rechteckigen Pumppuls zu einem geformten Puls vergrößert werden. [ABSTRACT FROM AUTHOR]

Distance and spins: A new broadband, frequency‐selective inversion pulse has been devised for pulsed electron–electron double resonance (PELDOR) spectroscopy, a unique method used to determine distance distributions between two or more paramagnetic centers 2–10 nm apart. The PELDOR modulation depth can be increased by substituting the rectangular pump pulse by a shaped pulse. [ABSTRACT FROM AUTHOR]

The inflammatory response is thought to contribute to secondary damage after spinal cord injury (SCI). Polyunsaturated fatty acids (PUFAs) play an important role in the onset and resolution of inflammation. Arachidonic acid (AA), an ω-6 PUFA, contributes to the initiation of inflammatory responses, whereas docosahexaenoic acid (DHA), an ω-3 PUFA, has antiinflammatory effects. Therefore, decreasing AA and increasing DHA levels after SCI might be expected to attenuate inflammation after SCI and promote tissue protection and functional recovery. We show here that daily oral administration of fenretinide after spinal cord contusion injury led to a significant decrease in AA and an increase in DHA levels in plasma and injured spinal cord tissue. This was accompanied by a significant reduction in tissue damage and improvement in locomotor recovery. Fenretinide also reduced the expression of proinflammatory genes and the levels of oxidative stress markers after SCI. In addition, in vitro studies demonstrated that fenretinide reduced TNF-α (tumor necrosis factor-α) expression by reactive microglia. These results demonstrate that fenretinide treatment after SCI can reduce inflammation and tissue damage in the spinal cord and improve locomotor recovery. These beneficial effects may be mediated via the ability of fenretinide to modulate PUFA homeostasis. Since fenretinide is currently in clinical trials for the treatment of cancers, this drug might be a good candidate for the treatment of acute SCI in humans. [ABSTRACT FROM AUTHOR]

Most states provide public technical assistance to help private landowners manage their forests. This article summarizes the results of a case study evaluating the public forestry assistance program in Georgia. Forest harvesting practices made by private landowners who received public forestry assistance were compared with those who did not receive any assistance when making a timber sale and harvest. Assisted landowners generally had greater returns from harvests, which could be imputed to yield large private, social, and program benefit cost ratios. [ABSTRACT FROM PUBLISHER]

A photo quiz about the most likely diagnosis of a woman with a history of oral herpes simplex virus, with sore throat, cough, headache, fatigue and fever is presented.

Power-law scaling from continuum percolation theory is applied to relate two soil properties: saturated hydraulic conductivity and air permeability under completely dry conditions. Combining the effective porosity-dependent models provides a physical interpretation for a previously published logarithmic relationship between the two properties. The saturated hydraulic conductivity, Ks, is a fundamental characteristic of subsurface flow and the hydrologic cycle. However, direct measurement of Ks is time consuming. Recently, air permeability measurements at 50 and 100 cm of H2O tension, a relatively dry condition in coarse and medium-textured soils, have been used to estimate Ks. In this short communication, we present a theoretical framework for relating Ks to ka(...), the air permeability as a function of porosity, ..., under completely dry conditions. We used powerlaw scaling from continuum percolation theory to develop a theoretical relationship between Ks and ka(...). Our result, similar in form to a published logarithmic equation with empirical coefficients, gives a physical interpretation to these empirical coefficients. [ABSTRACT FROM AUTHOR]