If you build it, will they come? Is test site availability a root cause of geographic disparities in COVID-19 testing?

OBJECTIVES: The purpose of this study was to examine the relationship between test site availability and testing rate within the context of social determinants of health. STUDY DESIGN: A retrospective ecological investigation was conducted using statewide COVID-19 testing data between March 2020 and December 2021. METHODS: Ordinary least squares and geographically weighted regression were used to estimate state and ZIP code level associations between testing rate and testing sites per capita, adjusting for neighbourhood-level confounders. RESULTS: The findings indicate that site availability is positively associated with the ZIP code level testing rate and that this association is amplified in communities of greater economic deprivation. In addition, economic deprivation is a key factor for consideration when examining ethnic differences in testing in medically underserved states. CONCLUSION: The study findings could be used to guide the delivery of testing facilities in resource-constrained states.

Efficacy of Topical Vancomycin- and Gentamicin-Loaded Calcium Sulfate Beads or Systemic Antibiotics in Eradicating Polymicrobial Biofilms Isolated from Diabetic Foot Infections within an In Vitro Wound Model.

Diabetic foot ulcers are notoriously difficult to heal, with ulcers often becoming chronic, in many cases leading to amputation despite weeks or months of antibiotic therapy in addition to debridement and offloading. Alternative wound biofilm management options, such as topical rather than systemic delivery of antimicrobials, have been investigated by clinicians in order to improve treatment outcomes. Here, we collected blood and tissue from six subjects with diabetic foot infections, measured the concentrations of antibiotics in the samples after treatment, and compared the microbiota within the tissue before treatment and after 7 days of antibiotic therapy. We used an in vitro model of polymicrobial biofilm infection inoculated with isolates from the tissue we collected to simulate different methods of antibiotic administration by simulated systemic therapy or topical release from calcium sulfate beads. We saw no difference in biofilm bioburden in the models after simulated systemic therapy (representative of antibiotics used in the clinic), but we did see reductions in bioburden of between 5 and 8 logs in five of the six biofilms that we tested with topical release of antibiotics via calcium sulfate beads. Yeast is insensitive to antibiotics and was a component of the sixth biofilm. These data support further studies of the topical release of antibiotics from calcium sulfate beads in diabetic foot infections to combat the aggregate issues of infectious organisms taking the biofilm mode of growth, compromised immune involvement, and poor systemic delivery of antibiotics via the bloodstream to the site of infection in patients with diabetes.

Comparative performance assessment of beam hardening correction algorithms applied on simulated data sets.

Beam hardening artefacts deteriorate the reconstructed image quality in industrial computed tomography. The appearances of beam hardening artefacts can be cupping effects or streaks. They impair the image fidelity to the object being scanned. This work aims at comparing a variety of commonly used beam hardening correction algorithms in the context of industrial computed tomography metrology. We choose four beam hardening correction algorithms of different types for the comparison. They are a single-material linearization algorithm, a multimaterial linearization algorithm, a dual-energy algorithm and an iterative reconstruction algorithm. Each beam hardening correction algorithm is applied to simulated data sets of a dual-material phantom consisting of multiple rods. The comparison is performed on data sets simulated both under ideal conditions and with the addition of quantum noise. The performance of each algorithm is assessed with respect to its effect on the final image quality (contrast-to-noise ratio, spatial resolution), artefact reduction (streaks, cupping effects) and dimensional measurement deviations. The metrics have been carefully designed in order to achieve a robust and quantifiable assessment. The results suggest that the single-material linearization algorithm can reduce beam hardening artefacts in the vicinity of one material. The multimaterial linearization algorithm can further reduce beam hardening artefacts induced by the other material and improve the dimensional measurement accuracy. The dual-energy method can eliminate beam hardening artefacts, and improve the low contrast visibility and dimensional measurement accuracy. The iterative algorithm is able to eliminate beam hardening streaks. However, it induces aliasing patterns around the object edge, and its performance depends critically upon computational power. The contrast-to-noise ratio and spatial resolution are declined by noise. Noise also increases the difficulty of image segmentation and quantitative analysis. LAY DESCRIPTION: X-ray computed tomography (CT) is a major breakthrough in digital imaging technology in the late 20th century. First used as an important tool in medical imaging, CT has gradually introduced to the nonmedical areas (e.g. industrial nondestructive testing). Inherently CT is more prone to artefacts comparing to the conventional real-time X-ray image. Beam hardening artefacts caused by the polychromatic nature of X-ray spectra are known to deteriorate the reconstructed image quality in industrial CT. A number of beam hardening correction algorithms exist and are used across medical CT. However, there is a lack of research on their effectiveness on industrial CT. This study presents an in-depth beam hardening correction algorithm comparison in industrial CT. Since this study takes various factors of the algorithm performance into account, it provides insights of the advantages and disadvantages of each algorithm and assists the choice of algorithm to meet specific needs of industry. Existing beam hardening correction algorithms are divided into the following four categories: linearization, segmentation based linearization, dual-energy and iterative methods. Since the linearization method can only correct single-material objects, we did not include it in the comparative study. Among the remaining categories, we chose one from each category for comparison, for methods in one peer category share similar physical and mathematical principles. The methods are polynomial fit, Joseph segmentation, dual energy and IMPACT iterative method. This study uses a simulated polychromatic data set of a multimaterial phantom. The central slice of the corrected reconstructions is then assessed and the results are presented. In this study, we will compare beam hardening correction methods with respect to their performance on image quality, the removal of image artefacts and the influence on dimensional accuracy.

Differential Response of Neural Cells to Trauma-Induced Swelling In Vitro.

Brain edema and the associated increase in intracranial pressure are major consequences of traumatic brain injury (TBI) that accounts for most early deaths after TBI. We recently showed that acute severe trauma to cultured astrocytes results in cell swelling. We further examined whether trauma induces cell swelling in neurons and microglia. We found that severe trauma also caused cell swelling in cultured neurons, whereas no swelling was observed in microglia. While severe trauma caused cell swelling in both astrocytes and neurons, mild trauma to astrocytes, neurons, and microglia failed to cell swelling. Since extracellular levels of glutamate are increased in brain post-TBI and microglia are known to release cytokine, and direct exposure of astrocytes to these molecules are known to stimulate cell swelling, we examined whether glutamate or cytokines have any additive effect on trauma-induced cell swelling. Exposure of cultured astrocytes to trauma caused cell swelling, and such swelling was potentiated by the exposure of traumatized astrocytes to glutamate and cytokines. Conditioned medium (CM) from traumatized astrocytes had no effect on neuronal swelling post-trauma, while CM from traumatized neurons and microglia potentiated the effect of trauma on astrocyte swelling. Further, trauma significantly increased the Na-K-Cl co-transporter (NKCC) activity in neurons, and that inhibition of NKCC activity diminished the trauma-induced neuronal swelling. Our results indicate that a differential sensitivity to trauma-induced cell swelling exists in neural cells and that neurons and microglia are likely to be involved in the potentiation of the astrocyte swelling post-trauma.

Tree biomass in the Swiss landscape: nationwide modelling for improved accounting for forest and non-forest trees.

Trees outside forest (TOF) can perform a variety of social, economic and ecological functions including carbon sequestration. However, detailed quantification of tree biomass is usually limited to forest areas. Taking advantage of structural information available from stereo aerial imagery and airborne laser scanning (ALS), this research models tree biomass using national forest inventory data and linear least-square regression and applies the model both inside and outside of forest to create a nationwide model for tree biomass (above ground and below ground). Validation of the tree biomass model against TOF data within settlement areas shows relatively low model performance (R 2 of 0.44) but still a considerable improvement on current biomass estimates used for greenhouse gas inventory and carbon accounting. We demonstrate an efficient and easily implementable approach to modelling tree biomass across a large heterogeneous nationwide area. The model offers significant opportunity for improved estimates on land use combination categories (CC) where tree biomass has either not been included or only roughly estimated until now. The ALS biomass model also offers the advantage of providing greater spatial resolution and greater within CC spatial variability compared to the current nationwide estimates.

Haemorrhoids are associated with internal iliac vein reflux in up to one-third of women presenting with varicose veins associated with pelvic vein reflux.

OBJECTIVES: To determine the prevalence of haemorrhoids in women with pelvic vein reflux, identify which pelvic veins are associated with haemorrhoids and assess if extent of pelvic vein reflux influences the prevalence of haemorrhoids. METHODS: Females presenting with leg varicose veins undergo duplex ultrasonography to assess all sources of venous reflux. Those with significant reflux arising from the pelvis are offered transvaginal duplex ultrasound (TVS) to evaluate reflux in the ovarian veins and internal Iliac veins and associated pelvic varices in the adnexa, vulvar/labial veins and haemorrhoids. Patterns and severity of reflux were evaluated. RESULTS: Between January 2010 and December 2012, 419 female patients with leg or vulvar varicose vein patterns arising from the pelvis underwent TVS. Haemorrhoids were identified on TVS via direct tributaries from the internal Iliac veins in 152/419 patients (36.3%) and absent in 267/419 (63.7%). The prevalence of the condition increased with the number of pelvic trunks involved. CONCLUSION: There is a strong association between haemorrhoids and internal Iliac vein reflux. Untreated reflux may be a cause of subsequent symptomatic haemorrhoids. Treatment with methods proven to work in conditions caused by pelvic vein incompetence, such as pelvic vein embolisation and foam sclerotherapy, could be considered.

Preparing for your annual staff appraisal: part 2.

Annual appraisals are part of performance management and are designed to motivate, develop and support employees in performing their roles to the highest possible standard. They provide an opportunity for constructive discussion of performance, identification of areas for development and agreement of approaches by which employees needs could be met. Part 1 of this article was concerned with preparation of the employee and manager for annual staff appraisal. This article provides advice for managers who perform annual appraisal interviews. Guidance is offered on how to ensure the strategic objectives of the team and healthcare organisation are met, a balanced understanding of nurse performance is achieved, and future objectives are identified and agreed

Healing rates following venous surgery for chronic venous leg ulcers in an independent specialist vein unit.

OBJECTIVES: This is a retrospective study over 12 years reporting the healing rates of leg ulcers at a specialist vein unit. All patients presented with active chronic venous leg ulcers (clinical,aetiological, anatomical and pathological elements [CEAP]: C6) and had previously been advised elsewhere that their ulcers were amenable to conservative measures only. METHOD: Seventy-two patients (84 limbs) were treated between March 1999 and June 2011. Patients were contacted in August 2011 by questionnaire and telephone. Of 72 patients,two were deceased and two had moved location at follow-up, so were not contactable. Fifty patients replied and 18 did not (response rate 74%), representing a mean follow-uptime of 3.1 years. RESULTS: Ulcer healing occurred in 85% (44 of 52 limbs) of which 52% (27) limbs were no longer confined to compression. Clinical improvement was achieved in 98% of limbs. CONCLUSIONS: This study shows that a significant proportion of ulcers currently managed conservatively can be healed by surgical intervention.

Nonoccupational post-exposure prophylaxis source tracing: is it really feasible in Australia?

OBJECTIVE: A Swiss nonoccupational post-exposure prophylaxis (NPEP) source-tracing study successfully reduced unnecessary NPEP prescriptions by recruiting and testing source partners of unknown HIV serostatus. The Victorian NPEP Service in Australia attempted to replicate this study with the addition of HIV rapid testing and a mobile service. METHODS: Patients presenting to two busy NPEP sites who reported a source partner of unknown HIV status were routinely asked if their source could be traced. If the exposed person indicated that their source partner was traceable they were asked to contact them and discuss the possibility of having an HIV test. RESULTS: No sources were enrolled and the study was terminated. CONCLUSION: We hypothesize that there are a number of differences between Australia and Switzerland that make source tracing unfeasible in Australia.

Non-occupational post-exposure prophylaxis in Victoria, Australia: responding to high rates of re-presentation and low rates of follow-up.

In Australia, the non-occupational post-exposure prophylaxis service in Victoria (VNPEPS) maintains a database of non-occupational post-exposure prophylaxis (NPEP) use throughout the state. Through the database the service can monitor and respond to patterns of NPEP presentation, re-presentation and follow-up as well as those who test positive for HIV. We describe a cohort of NPEP individuals from the commencement of the service to 31 December 2009. During this time, 1864 individuals presented for NPEP on 2396 occasions. The majority (85%) were men who have sex with men (MSM) presenting after receptive anal intercourse (56.1%). Repeat NPEP presentations were high (17.5%) and follow-up testing at week 12 post-NPEP was low (34%). Twenty-two patients (1.2%) tested positive for HIV at baseline presentation and six patients seroconverted to HIV during follow-up. The VNPEPS has initiated strategies to encourage behaviour change for those who re-present for NPEP, and to improve rates of week 12 follow-up.

Improving clinical reasoning in children's nursing through narrative analysis.

This article introduces the reader to the use of narratives to inform and enhance patient care. In this context narratives are specific stories about patient care that children's nurses discuss with one another, or with members of the multidisciplinary team, or that are relayed to them by patients and families. It is argued that an understanding of different narratives--children's, parents', young people's, our own and those of other healthcare professionals--will assist the children's nurse to act more sensitively, effectively and imaginatively.

Anthropogenic metal contamination and sapropel imprints in deep Mediterranean sediments.

Sediment cores from the deep Balearic basin and the Cretan Sea provide evidence for the accumulation of Cd, Pd and Zn in the top few centimeters of the abyssal Mediterranean sea-bottom. In both cores, 206Pb/207Pb profiles confirm this anthropogenic impact with less radiogenic imprints toward surface sediments. The similarity between excess 210Pb accumulated in the top core and the 210Pb flux suggests that top core metal inventories reasonably reflect long-term atmospheric deposition to the open Mediterranean. Pb inventory in the western core for the past 100 years represents 20-30% of sediment coastal inventories, suggesting that long-term atmospheric deposition determined from coastal areas has to be used cautiously for mass balance calculations in the open Mediterranean. In the deeper section of both cores, Al normalized trace metal profiles suggest diagenetic remobilization of Fe, Mn, Cu and, to a lesser extent, Pb that likely corresponds to sapropel event S1.

Effects of high-oil corn on feedlot performance, carcass characteristics, fatty acid profiles, beef palatability, and retail case life traits of beef top loin steaks.

Our objective was to compare the effects of feeding steam-flaked, high-oil corn with normal steam-flaked corn to which yellow grease was added to equalize dietary fat on performance and carcass characteristics of finishing beef steers, and palatability, retail case life, and fatty acid composition of strip loins. Angus steers (n = 120; initial BW = 288 kg) were allotted to dietary treatments consisting of 1) normal mill-run, steam-flaked corn plus added fat (NMR) or 2) high-oil, steam-flaked corn (HOC) and assigned randomly to pens (12 pens/treatment with 5 steers/pen). Performance (ADG, DMI, and G:F) was measured over time, and cattle were shipped to a commercial abattoir for collection of carcass data after 165 d on feed. Carcass data were collected at 48 h postmortem on all carcasses, and 2 carcasses from each pen were selected randomly for collection of strip loins (IMPS #180A). At 14 d postmortem, 4 steaks (2.54 cm thick) were removed for retail display, trained sensory panel analysis, Warner-Bratzler shear force determination, and fatty acid analysis. Daily BW gain was greater (P = 0.03) and G:F was increased 8.4% (P = 0.01) for steers fed NMR compared with HOC, but DMI was not affected (P > 0.10) by treatment. No treatment differences were observed (P > 0.10) for HCW, 12th-rib fat, KPH, and yield grade. Marbling scores were greater (P = 0.01) for NMR than for HOC, and LM area tended (P = 0.07) to be greater in NMR than in HOC carcasses. The proportion of carcasses grading USDA Choice did not differ (P = 0.77) between treatments, but a greater (P = 0.04) proportion of carcasses graded in the upper two-thirds of Choice for NMR vs. HOC. Trained sensory panel traits and Warner-Bratzler shear force values did not differ between treatments (P > 0.10), and no differences (P > 0.10) were detected for purge loss or fatty acid composition. Overall, ADG and G:F were less and marbling score was decreased, but there were no differences between treatments in beef palatability, retail case life, or concentrations of fatty acids in strip loins.

Improving local healthcare policies and practices.

Nurses often have an important role in devising or updating local policies and protocols, but are rarely prepared for a process that requires careful consideration of existing resources and the factors influencing change. This article explores and offers practical guidance on the process involved in preparing policies and protocols.

Effective drug delivery, in vitro and in vivo, by carbon-based nanovectors noncovalently loaded with unmodified Paclitaxel.

Many new drugs have low aqueous solubility and high therapeutic efficacy. Paclitaxel (PTX) is a classic example of this type of compound. Here we show that extremely small (<40 nm) hydrophilic carbon clusters (HCCs) that are PEGylated (PEG-HCCs) are effective drug delivery vehicles when simply mixed with paclitaxel. This formulation of PTX sequestered in PEG-HCCs (PTX/PEG-HCCs) is stable for at least 20 weeks. The PTX/PEG-HCCs formulation was as effective as PTX in a clinical formulation in reducing tumor volumes in an orthotopic murine model of oral squamous cell carcinoma. Preliminary toxicity and biodistribution studies suggest that the PEG-HCCs are not acutely toxic and, like many other nanomaterials, are primarily accumulated in the liver and spleen. This work demonstrates that carbon nanomaterials are effective drug delivery vehicles in vivo when noncovalently loaded with an unmodified drug.

Deep vein thrombosis (DVT) after venous thermoablation techniques: rates of endovenous heat-induced thrombosis (EHIT) and classical DVT after radiofrequency and endovenous laser ablation in a single centre.

INTRODUCTION: Deep vein thrombosis (DVT) after varicose vein surgery is well recognised. Less well documented is endovenous heat-induced thrombosis (EHIT), thrombus extension into a deep vein after superficial venous thermoablation. We examined the rates of DVT in our unit after radiofrequency (RFA) and endovenous laser ablation (EVLA) with specific attention to thrombus type. METHOD: Retrospective analysis of all cases of RFA under general anaesthesia and EVLA under local anaesthesia was performed. Cases of DVT were identified from the unit database and analysed for procedural details. RESULTS: In total, 2470 cases of RFA and 350 of EVLA were performed. Post-RFA, DVT was identified in 17 limbs (0.7%); 4 were EHIT (0.2%). Concomitant small saphenous vein (SSV) ligation and stripping was a risk factor for calf-DVT (OR 3.4, 95%CI 1.2-9.7, P=0.036), possibly due to an older patient group with more severe disease. Post-EVLA, 4 DVTs were identified (1%), of which 3 were EHIT (0.9%). CONCLUSION: The DVT rate including EHIT was similar in patients treated with RFA and EVLA and was low. Routine post-operative duplex ultrasound scanning is recommended until the significance of EHIT is better understood, in accordance with consensus guidelines. DVT rates for both techniques compare favourably with those published for saphenous vein stripping.

Diameter-dependent solubility of single-walled carbon nanotubes.

We study the solubility and dispersibility of as-produced and purified HiPco single-walled carbon nanotubes (SWNTs). Variation in specific operating conditions of the HiPco process are found to lead to significant differences in the respective SWNT solubilities in oleum and surfactant suspensions. The diameter distributions of SWNTs dispersed in surfactant solutions are batch-dependent, as evidenced by luminescence and Raman spectroscopies, but are identical for metallic and semiconducting SWNTs within a batch. We thus find that small diameter SWNTs disperse at higher concentration in aqueous surfactants and dissolve at higher concentration in oleum than do large-diameter SWNTs. These results highlight the importance of controlling SWNT synthesis methods in order to optimize processes dependent on solubility, including macroscopic processing such as fiber spinning, material reinforcement, and films production, as well as for fundamental research in type selective chemistry, optoelectronics, and nanophotonics.

Medical, social and societal issues in infants with abusive head trauma.

Abusive head trauma (AHT) is the leading cause of death from traumatic brain injury in under 2 year olds. AHT presents with acute encephalopathy, subdural hemorrhages and retinal hemorrhages occurring in the context of an inappropriate or inconsistent history. We retrospectively analyzed, over a 10 year period, admissions and transfers to our hospital with suspected AHT to assess patterns of presentation, presenting symptoms, investigations, subsequent confirmation, social work input and both neurological and social outcomes. We analyzed all suspected AHT infants and children looking for the time of presentation, presenting symptoms, caregivers concerns prior to presentation, a family profile including stressors, investigations (in particular neuroradiology and ophthalmology assessments), treatment in hospital, length of stay in hospital, social work involvement, subsequent discharge, neurological outcome and subsequent social work follow up. Data was collected from the hospital HIPE system, RIS (radiology reports system) and records from the social work department from a period October 1998 to January 2009 inclusive. Of 22 patients with confirmed AHT, ages seizures and irritability followed by vomiting, poor feeding, a bulging fontanelle and lethargy. The father was the sole minder in 5 cases. There was a delayed history in 4 cases. One had multiple visits to his GP. All cases had subdural hemorrhages proven by either CT or MRI scans and retinal hemorrhages diagnosed by ophthalmology. One infant presented with a torn frenulum. Four had suspicious bruising. All had normal coagulation profiles, skeletal surveys and extensive metabolic tests. Hospital stays ranged from 1 to 124 days (the median was 28 days and mean 33 days). Ten (45%) infants required ventilatory support. Sixteen infants had social work involvement within 4 days of admission (7 of these were interviewed immediately). Outcomes after case conferences were that 6 returned home with parents, 9 were placed in foster care. Four parents (18%) admitted to shakng their infants. There was 1 death. Thirteen (60%) were normal on follow up. Two had ADHD. Two had language delay. Two had motor delay. One criminal prosecution has ensued as yet Children with suspected AHT should undergo appropriate investigations which should include brain imaging, ophthalmic examination, skeletal survey and blood investigations. Early social work assessment is a priority as part of the multidisciplinary approach. A prospective national study of AHT is required.

Disseminating best practice through workshops.

This article, the fourth in a five-part series, explores the ways in which best practice might be successfully disseminated through workshops. A workshop provides an exciting opportunity to engage nurses in new ways of thinking and the exploration of ideas applied to practice. It involves the nurse innovator in managing a learning experience that enables colleagues to explore their current and possible future practice. The article describes the different types of workshops available, the role of the workshop leader and the sorts of activities that might be used to encourage participation and practice development.

Disseminating best practice through teaching.

A nurse may be invited to deliver teaching sessions to students at a local university, especially if he or she has a reputation as a practice innovator. These invitations are an opportunity for the nurse to disseminate practice wisdom to a wider audience. Planning the session so that it is educational, stimulating and represents the nurse's experience and expertise is crucial. While leading such a session may seem daunting, there are several strategies that can increase the chance of success, and these are discussed in this article.