A bump in the node: The hydraulic implications of rhizomatous growth.

PREMISE: Rhizomatous growth characterizes numerous taxa among vascular plants. While abundant information exists on nutrient sharing and demography, the question of how these metameric organisms move water through their bodies remains largely unstudied. Moreover, we lack an understanding of the evolutionary implications of rhizomatous growth across vascular plants. Here, we examined these questions by investigating how rhizomatous growth and vascular construction affect whole-plant hydraulic function. METHODS: In five terrestrial fern species with diverse vascular construction, we used microcomputed tomography and bright-field microscopy to examine vascular construction across nodes along the rhizome. These data were integrated with measurements of leaf stomatal conductance under rooted and uprooted conditions to relate vascular patterning and hydraulic architecture to leaf water status. RESULTS: Similar to phytomers of woody seed plants, nodal regions in rhizomatous ferns are areas of hydraulic resistance. While water is shared along the rhizomes of these investigated species, hydraulic conductivity drops at nodes and stomatal conductance declines when nodes were locally uprooted. Together, our data suggest that nodes are chokepoints in axial water movement along the rhizome. CONCLUSIONS: Nodal chokepoints decrease hydraulic integration between phytomers. At the same time, chokepoints may act as "safety valves", hydraulically localizing each phytomer-potentially decreasing embolism and pathogen spread. This suggests a potential trade-off in the principal construction of the fern rhizome. Moreover, we propose that shoot-borne roots (homorhizy) and the prostrate habit of rhizomatous ferns decrease the hydraulic and structural burdens that upright plants typically incur. The absence of these hydraulic and structural demands may be one reason ferns (and many rhizomatous plants) lack, or have minimally developed, secondary xylem.

High-responsivity operation of quantum cascade detectors at 9 µm.

Quantum cascade detectors (QCDs) are devices operating at zero external bias with a low dark-current. They show linear detection and high saturation intensities, making them suitable candidates for heterodyne detection in long-wave infrared (LWIR) free space optical communication systems. We present an approach to mitigate the performance limitation at long wavelengths, by a comparison of similar single and multi-period QCDs for optimizing their responsivity and noise behaviour. Our InGaAs/InAlAs/InP ridge QCDs are designed for operation at λ = 9.124 µm. Optical waveguide simulations support the accurate optical characterization. A detailed device analysis reveals room-temperature responsivities of 111 mA/W for the 15-period and 411 mA/W for the single-period device.

Education and devices to prevent blood and body fluid exposures.

BACKGROUND: Healthcare workers are at risk of blood and body fluid exposures (BBFE) while delivering care to patients. Despite recent technological advances such as safety-engineered devices (SEDs), these injuries continue to occur in healthcare facilities worldwide. AIMS: To assess the impact of an education and SEDs workplace programme on rates of reported exposures. METHODS: A retrospective cohort study, utilizing interrupted time series analysis to examine reported exposures between 2005 and 2015 at a 600-bed hospital in Perth, Western Australia. The hospital wards were divided into four cohorts. RESULTS: A total of 2223 records were available for analysis. The intervention was most effective for the first cohort, with significant improvements both short-term (reduction of 12 (95% CI 7-17) incidents per 1000 full-time equivalent (FTE) hospital staff) and long-term (reduction of 2 (CI 0.6-4) incidents per 1000 FTE per year). Less significant or consistent impacts were observed for the other three cohorts. Overall, the intervention decreased BBFE exposure rates at the hospital level from 19 (CI 18-20) incidents per 1000 FTE pre-intervention to 11 (CI 10-12) incidents per 1000 FTE post-intervention, a 41% reduction. No exposures resulted in a blood-borne virus infection. CONCLUSIONS: The intervention was most effective in reducing exposures at a time when incidence rates were increasing. The overall effect was short-term and did not further reduce an already stabilized trend, which was likely due to improved safety awareness and practice, induced by the first cohort intervention.

Self-management recommendations for sickle cell disease: A content analysis of websites.

This authors report on the findings of a study designed to establish website-based self-management recommendations for sickle cell disease. Google and Yahoo search engines were used to search the World Wide Web. Purposive sampling was used to select 28 websites that met the inclusion criteria. Data were manually collected from health education materials and subjected to qualitative content analysis. Self-management was conceptualized as actions involving preventive health, self-monitoring, self-diagnosing, and self-treatment. The results show that the websites recommend more self-management actions for preventive health and self-treatment than for self-monitoring and self-diagnosis. Frequent oral fluid intake, limitation of overactivity, eating a healthy diet, avoiding extreme temperatures, and infections were the most common preventive health recommendations. Daily pain monitoring and general bodily inspections were the most frequent self-monitoring recommendations. Commonly cited self-diagnostic indicators were fever, persistent pain, enlarged spleen, and leg ulcers. The use of analgesics and nonpharmacological measures were regularly cited for self-treatment. Most recommendations were assessed as clinically safe as they align with standards for sickle cell management. Nurses and other professionals should teach clients how to assess the credibility of websites.

Tuberculosis screening among HIV-infected patients: tuberculin skin test vs. interferon-gamma release assay.

National guidelines recommend screening for latent tuberculosis infection (LTBI) in all HIV-infected patients. Thus, the objective of this study was to measure protocol adherence to national guidelines regarding LTBI screening for HIV-infected patients entering care at an urban primary care clinic specializing in HIV care, identify clinical and other characteristics associated with adherence, and determine whether transitioning from the tuberculin skin test (TST) to the interferon-gamma release assay (IGRA) improved adherence. We conducted a retrospective study using protocol adherence to LTBI screening guidelines within twelve months of entering care at an HIV clinic as the primary outcome. Successful protocol adherence was defined as the placement and reading of a TST, performance of an IGRA, or a note in study clinic records documenting prior testing or treatment for tuberculosis in an outside setting. Multivariable modified Poisson regression models were used in analyses. Overall, 32% (n = 118/372) of patients received LTBI screening within twelve months of entering care. Protocol adherence to LTBI screening guidelines increased from 28% to 37% following the transition from TST to IGRA screening. IGRA screening [adjusted prevalence ratio: 1.45, 95% confidence limits: (1.07, 1.96)], male sex [1.47 (1.05, 2.07)], transfer patient status [1.51 (1.05, 2.18)], and greater than one year of clinic attendance [1.62 (1.06, 2.48)] were independently associated with protocol adherence. Among patients without prior LTBI screening or treatment, patients entering the clinic in 2013 under the IGRA screening protocol were more likely to be screened for LTBI compared to patients entering under the TST screening protocol (34.3% vs. 9.7%, p < 0.001). In conclusion, transitioning from TST to IGRA-based screening improved adherence to screening guidelines. However, further work on improving adherence to LTBI screening guidelines among HIV-infected patients is needed.

4.3 µm quantum cascade detector in pixel configuration.

We present the design simulation and characterization of a quantum cascade detector operating at 4.3µm wavelength. Array integration and packaging processes were investigated. The device operates in the 4.3µm CO2 absorption region and consists of 64 pixels. The detector is designed fully compatible to standard processing and material growth methods for scalability to large pixel counts. The detector design is optimized for a high device resistance at elevated temperatures. A QCD simulation model was enhanced for resistance and responsivity optimization. The substrate illuminated pixels utilize a two dimensional Au diffraction grating to couple the light to the active region. A single pixel responsivity of 16mA/W at room temperature with a specific detectivity D* of 5⋅107 cmHz/W was measured.

Anorectal biofeedback for neurogenic bowel dysfunction in incomplete spinal cord injury.

STUDY DESIGN: A case-control study of prospectively collected data was performed. OBJECTIVES: To compare anorectal biofeedback (BF) outcomes in patients with incomplete motor spinal cord injury (SCI) and neurogenic bowel dysfunction (NBD) with a group of functional anorectal disorder-matched control patients. SETTING: Neurogastroenterology Unit affiliated with a Spinal Injury Unit in a tertiary referral centre in Sydney, Australia. METHODS: All consecutive patients with SCI and NBD referred for anorectal manometry and BF were matched in a 1:2 ratio with age, gender, parity and functional anorectal disorder-matched control patients. Instrumented BF was performed in six nurse-guided weekly visits. Outcomes included changes in anorectal physiology measures, symptom scores and quality-of-life measures. RESULTS: Twenty-one patients were included. These were matched with 42 patient controls. Following BF, symptom scores improved significantly in both groups, as did effect of bowel disorder on quality of life. Improvement in these measures did not differ between the groups. Patients with SCI and NBD showed improvement in their sensory and motor anorectal function, including lowering of first sensation threshold and more effective balloon expulsion. CONCLUSIONS: Patients with incomplete motor SCI responded as well to anorectal BF as functional anorectal disorder-matched controls. Spinal cord-injured patients also showed improvement in anorectal sensorimotor dysfunction and balloon expulsion. These novel findings indicate that clinicians should not be dissuaded from considering behaviour-based therapeutic interventions such as anorectal BF in selected spinal cord-injured patients.

Quantum cascade detector utilizing the diagonal-transition scheme for high quality cavities.

A diagonal optically active transition in a quantum cascade detector is introduced as optimization parameter to obtain quality factor matching between a photodetector and a cavity. A more diagonal transition yields both higher extraction efficiency and lower noise, while the reduction of the absorption strength is compensated by the resonant cavity. The theoretical limits of such a scheme are obtained, and the impact of losses and cavity processing variations are evaluated. By optimizing the quantum design for a high quality cavity, a specific detectivity of 10(9) Jones can be calculated for λ = 8µm and T = 300K.

Nucleation of Ga droplets on Si and SiOx surfaces.

We report on gallium droplet nucleation on silicon (100) substrates with and without the presence of the native oxide. The gallium deposition is carried out under ultra-high vacuum conditions at temperatures between 580 and 630 °C. The total droplet volume, obtained from a fit to the diameter-density relation, is used for sample analysis on clean silicon surfaces. Through a variation of the 2D equivalent Ga thickness, the droplet diameter was found to be between 250-1000 nm. Longer annealing times resulted in a decrease of the total droplet volume. Substrate temperatures of 630 °C and above led to Ga etching into the Si substrates and caused Si precipitation around the droplets. In contrast, we obtained an almost constant diameter distribution around 75 nm over a density range of more than two orders of magnitude in the presence of a native oxide layer. Furthermore, the droplet nucleation was found to correlate with the density of surface features on the 'epi-ready' wafer.

Venous leg ulcers: what about well-being?

The impact of having a leg ulcer is well-documented in terms of the pain, restrictions and psychosocial difficulties that patients experience. However, the current focus on quality of life as a patient reported outcome measure overlooks the importance of the individual's well-being. In this article, we argue that a shift in focus from quality of life to well-being will contribute to the more proactive patient centred approach to care to which we should all aspire in contemporary care settings.

Different sonographic presentations of dermatofibrosarcoma protuberans.

BACKROUND: Dermatofibrosarcoma protuberans (DFSP) is a low-grade spindle cell sarcoma of fibroblastic origin. This tumor originates in the dermis and infiltrates the subcutaneous tissue. The highest incidence occurs in the third and fourth decades of life, affecting most frequently the trunk and proximal extremities. Ultrasound is performed in those cases where the clinical appearance of the lesion is not typical and when the physician wants to determine the extent and depth of the lesion. MATERIAL AND METHODS: Retrospective analysis of the ultrasound and demographic findings of thirteen patients with DFSP. RESULTS: 13 patients, 8 females and 5 males, aged from 2 months to 58 years old. One patient with two different separated synchronous tumors. On ultrasonography they compromised the dermal hypodermal layers in 93% of the cases and 1 dermal lesion. The compromise reached the aponeurotic plane in two cases. The sized varied from 5 to 38 mm. They presented as a well-defined hypoechogenic nodule in seven cases (50%). In three cases (21%) they presented as a hypoechogenic infiltrate ill-defined border solid lesion; in two cases as a plaque ill-defined lesion, and two cases as a pseudonodular inflammatory lesion with irregular borders. All lesions appeared vascularized on color Doppler imaging. CONCLUSION: DFSP is a low grade sarcoma of fibroblastic origin, that usually arises in the dermis and infiltrates the subcutaneous tissue. The clinical presentations are variable. On ultrasound we found different patterns: well-defined hypoechogenic solid nodule, hypoechogenic infiltrate ill-defined border solid lesion, plaque ill-defined lesion, and pseudonodular inflammatory lesion. It is important to know and recognize this suspicious different ultrasound presentations in order to recommend a histological study.

Negative pressure wound therapy: improving the patient experience. Part 1 of 3.

Negative pressure wound therapy (NPWT) is an effective treatment for healing wounds, which may have additional benefits, such as reduced time spent in hospital and fewer dressing changes. However, as with most wound treatments, NPWT can be painful for some patients. Research has shown that the pain and accompanying stress of wound care can impair patient quality of life and delay the healing process, highlighting the need to explore ways in which the patient experience of NPWT might be improved. This article presents part one of three studies which aimed to investigate the above. In the present study, an online survey was used to explore the views of wound care clinicians worldwide (n = 221) on NPWT and levels of pain, stress and skin trauma in patients during the different stages of treatment. Findings suggest that, in the opinion of clinicians, patients' pain levels vary during the different stages of NPWT and that removal of the wound fillers and dressings or covering films are the most painful stages.

Negative pressure wound therapy: improving the patient experience Part 2 of 3.

Despite the clear benefits of negative pressure wound therapy (NPWT) as a treatment for wounds, it is essential that greater focus is given to the patient experience of this treatment. In particular, it is important that any unpleasant consequences, such as pain, stress, and skin trauma are minimised, so as to promote quality of life and healing. This article presents part two of three studies which aim to explore ways in which the patient experience of NPWT can be improved. In this study, the views of wound care clinicians (n=12) were investigated in greater depth through semi-structured interviews. Findings indicate a pressing need to minimise pain, particularly through ongoing assessment and collaboration with patients, and also through the use of appropriate dressings, films and other products that promote patient comfort. Additionally, it is evident that greater education is needed for both nurses and patients about NPWT, in order to promote high-quality care and patient wellbeing.

Sleep disruption in patients with chronic leg ulcers.

OBJECTIVE: To investigate the incidence of sleep disruption in people with chronic leg ulcers and to explore which factors may contribute to sleep problems. METHOD: A questionnaire survey was completed by a convenience sample of 52 leg ulcer patients attending community-based Leg Clubs in England and Wales. The questionnaire assessed wound pain, quality of sleep, factors contributing to sleep disruption and general health. RESULTS: Sixty-nine per cent (n=36) of leg ulcer patients reported sleep disruption, with 88% stating that they wake at least once during the night. General wound pain was the most frequently-cited cause (58%), while pain associated with treatment affected the sleep of 38% of respondents. Additionally, nearly a third (n=14) expressed that worrying about their wound impacted on their sleep. A significant correlation was found between wound pain and sleep disruption. CONCLUSION: The findings suggest that the majority of leg ulcer patients suffer sleep disruption, either as a direct consequence of wound pain or due to treatment-related or psychological issues associated with the wound. This has important implications for patient quality of life and also for the healing process; therefore, assessment and management of sleep problems in leg ulcer patients is essential. DECLARATION OF INTEREST: This study was supported by a financial grant from Mölnlycke Health Care. The authors have no commercial or social conflicts of interest with respect to the article or its content.

Negative pressure wound therapy: improving the patient experience part 3 of 3.

Negative pressure wound therapy (NPWT) is considered to be an effective wound treatment, yet research has highlighted a clear need for its improvement, particularly in reducing pain. This is important not only for patient well-being and treatment satisfaction but also for the healing process. In parts 1 and 2, wound care clinicians were invited to share their views on patients' experiences of NPWT. Part 3, presented here, explores the views of patients who have had NPWT, through use of a questionnaire survey and interview (n = 50). Findings show that the majority of patients felt that NPWT had a positive impact on their wound (94%) and that their overall experience was positive (88%). However, respondents identified a number of challenges associated with NPWT, such as reduced mobility, noise issues, and sleep disturbance. Respondents also identified a number of areas for improvement with NPWT, including greater training for nurses, practical alterations to the equipment, and methods of minimising pain and skin damage during NPWT. Taken together with the findings from part one and two, this study highlights several key considerations for future research and clinical practice with NPWT.

Patients' experiences of negative pressure wound therapy for the treatment of wounds: a review.

OBJECTIVE: To review the research on patients' experiences of undergoing negative pressure wound therapy (NPWT). METHOD: A literature search was carried out using the following databases: Academic Search Complete, CINAHL, PsychINFO, MEDLINE, PubMed and PsyARTICLES. The search covered the period from 2001 to 2012, using the key words: ['negative pressure wound therapy' OR 'vacuum-assisted closure' OR 'topical negative therapy'] AND ['patients' experiences' OR 'psychological' OR 'stress' OR 'anxiety' OR 'wellbeing' OR 'pain' OR 'quality of life' OR 'physical']. RESULTS: Twenty-five relevant articles were included. NPWT is generally considered to be successful in reducing wound depth and facilitating healing. However, studies have highlighted a number of issues that need to be considered. For example, the type of dressing used during treatment can have a significant effect on patients' experience of pain. Furthermore, the NPWT system can cause patients to feel anxious due to both the patient and the health professional being unfamiliar with this form of treatment. It can also restrict patients' daily care and wider social life, which may result in a negative self-image and low self-esteem. Despite this, some studies have reported positive improvements to patients' quality of life. Additionally, since NPWT can lead to faster healing, any detrimental impact upon patients' wellbeing may be short-term and less prolonged than that of other treatments. CONCLUSION: Compared with other treatments, there is evidence to show that NPWT can lead to faster wound healing, and a reduced frequency of dressing changes and other treatments. However, there are a number of challenges with the use of NPWT, which need to be explored further so that improvements can be made. Specifically, certain aspects of NPWT may impact negatively on patients' wellbeing, albeit short-term. Therefore, research needs to explore patients' experience of NPWT throughout the treatment process and to consider how this can be improved to minimise any negative effects.

Minimal clinically important difference for comfortable speed as a measure of gait performance in patients undergoing inpatient rehabilitation after stroke.

[Purpose] The purpose of this retrospective study was to determine the minimal clinically important difference for comfortable gait speed for patients with stroke. [Subjects] Data were analyzed from 35 patients undergoing inpatient rehabilitation. [Methods] Two characteristics of gait were measured, assistance required and comfortable gait speed. Patients were grouped as either experiencing or not experiencing a decrease of 2 or more levels of assistance required over the course of rehabilitation. Receiver operating characteristic curve analysis was used to identify the change in gait speed that best differentiated between patients who did and did not experience the requisite decrease in assistance required for gait. [Results] Twenty-one patients decreased 2 or more levels of assistance whereas 14 did not. Walking speed increased significantly more in the group who experienced a decrease in assistance of at least 2 levels. The receiver operating characteristic curve analysis showed a change in walking speed of 0.13 m/s best distinguished between patients who did versus did not experience a reduction in assistance required. [Conclusion] An improvement in gait speed of 0.13 m/s or more is clinically important in patients with stroke.

Delhi's network for surveillance of antimicrobial resistance: The journey, challenges and output from first year.

PURPOSE: Antimicrobial resistance [AMR] has emerged as a global and national priority and establishing an effective surveillance system for antimicrobial resistance is an essential prerequisite for generating evidence for informed policymaking at both national and state levels. METHODS: Twenty-four laboratories were enrolled after assessment in the WHO-IAMM Network for Surveillance of Antimicrobial Resistance in Delhi [WINSAR-D]. The NARS- NET standard operating procedures were adopted along with its priority pathogen lists and antibiotic panels. The members were trained to use WHONET software and monthly data files were collected, collated, and analyzed. RESULTS: Multiple logistic issues such as procurement, erratic supply of consumables, non-availability of standard guidelines, lack of automated systems, high workload and low manpower were reported by the majority of member laboratories. Microbiological challenges such as differentiation between colonization and pathogen in absence of patient details, lack of confirmation of resistance, identification of isolates and lack of dedicated computer and genuine windows software for data were common to most laboratories. The total number of isolates of priority pathogens in 2020 was 31,463. Of these, 50.1% isolates were from urine 20.6% were from blood and 28.3% were from pus aspirate and other sterile body fluids. High levels of resistance were observed for all antibiotics. CONCLUSION: There are many challenges in generating quality AMR data in lower-middle-income countries. There is a need for resource allocation and capacity building at all levels to ensure the collection of quality assured data.

The prevalence of celiac disease among patients with nonconstipated irritable bowel syndrome is similar to controls.

BACKGROUND & AIMS: Guidelines recommend that patients with symptoms of nonconstipated irritable bowel syndrome (NC-IBS) undergo testing for celiac disease (CD). We evaluated the prevalence of CD antibodies, and biopsy confirmed CD among patients with NC-IBS in a large US population. METHODS: In a study conducted at 4 sites, from 2003 to 2008, we compared data from 492 patients with symptoms of NC-IBS to 458 asymptomatic individuals who underwent colonoscopy examinations for cancer screening or polyp surveillance (controls). All participants provided blood samples for specific and nonspecific CD-associated antibodies. Additionally, patients with IBS were analyzed for complete blood cell counts, metabolic factors, erythrocyte sedimentation rates, and levels of C-reactive protein and thyroid-stimulating hormone. Any subjects found to have CD-associated antibodies were offered esophagogastroduodenoscopy and duodenal biopsy analysis. RESULTS: Of patients with NC-IBS, 7.3% had abnormal results for CD-associated antibodies, compared with 4.8% of controls (adjusted odds ratio, 1.49; 95% confidence interval: 0.76-2.90; P=.25). Within the NC-IBS group, 6.51% had antibodies against gliadin, 1.22% against tissue transglutaminase, and 0.61% against endomysium (P>.05 vs controls for all antibodies tested). CD was confirmed in 0.41% of patients in the NC-IBS group and 0.44% of controls (P>.99). CONCLUSIONS: Although CD-associated antibodies are relatively common, the prevalence of CD among patients with NC-IBS is similar to that among controls in a large US population. These findings challenge recommendations to routinely screen patients with NC-IBS for CD. More than 7% of patients with NC-IBS had CD-associated antibodies, suggesting that gluten sensitivity might mediate IBS symptoms; further studies are needed.