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Background Sláintecare advocates for right care, in the right place at the right time. ANPs for Older Persons in the community are uniquely placed to deliver care as close as possible to the older person’s home and to lead a holistic, flexible model of care minimising admission to acute care and maximising existing local resources. A pilot programme aimed at providing ANP led comprehensive geriatric assessment (CGA) (with Geriatrician support) to older people in a defined area commenced in June 2019. This pilot was part of a larger Hub and Spoke model funded by Sláintecare which gave additional MDT support. Methods A referral template was designed. Criteria for referral included; age > 75 years, Rockwood Frailty Scale 4–6 (focusing on Falls, Cognitive Impairment and Complex Frailty). Older people on the cusp of requiring long term care (LTC) were also prioritised. A prospective database of patients was maintained by the ANP to evaluate the service. Results From June 2019 to August 2021, 156 patients received an ANP led CGA, mostly conducted in the home. 247 reviews were conducted at the local spoke clinic and 46 joint ANP/Geriatrician home visits. Majority of referrals were from GP (n = 69), hospital (n = 30), LTC reviews (n = 22) and Community Nursing Units (CNUs) (n = 19). 449 outpatient appointments have been removed from the tertiary referral centre. Independent case load management from the ANP includes further appointments, telephone follow up/advice and she is a point of contact where crises arise before referral to acute services. 99% of patients surveyed reported satisfaction with the service especially the ease of local access and home visits. Conclusion Older Persons’ ANP can provide longitudinal care pathways for older adults in the community in conjunction with ICPOP and local CNUs, intervening before crises emerge and providing continuity of care and an alternative to acute care.

Background In September 2019 Sláintecare helped establish an Integrated Care team for Older People. The aim of this service was to provide a Comprehensive Geriatric Assessment (CGA) to older people within a community network. Service user experience/feedback are critically important for development of a team and a service. To give service users a platform to evaluate the service a patient experience survey was conducted. Methods The survey was designed by the multidisciplinary team, consisting of 13 closed/3 open questions. A Likert scale was utilised for closed questions and thematic analysis for open questions. A question on impact of COVID-19 was also included. 150 of the 950 service users who received a CGA from June 2020 to June 2021 were selected randomly and invited to participate in the postal survey. All participants received a covering letter, questionnaire and a stamped address envelope to return their completed surveys. Results 47% response rate (71/150). 77% were aged ≥75. 52% completed the survey themselves, 48% required assistance. 61% attended more than twice and most would prefer to attend a local spoke clinic. 96% agreed/strongly agreed that they were satisfied with the service. 99% felt they were treated with dignity/respect and had confidence in the service. 93% agreed that they were involved in care decisions. 82% reported their carers had the opportunity to discuss concerns. Themes emerging included importance of care close to home, avoiding acute hospital, difficulty parking at tertiary centres. 42% highlighted isolation and loneliness due to COVID-19 as a major issue. Conclusion Service users had an overwhelmingly positive experience especially when care was delivered in clinics close to their homes. Development of the hub and spoke model is acceptable and feasible to older people and their carers’ in this region and will be the focus for expansion of this service.

Background Lifestyle modifications, in older at risk populations, may prevent or slow the rate of cognitive decline. Promotion of brain health has been recommended by the WHO and other governing bodies. Supporting patients in making these lifestyle changes, however, can be complex. Generic guidance may not apply to all in a heterogenous and frail patient cohort, when physical mobility may be limited and weight loss/nutrition a concern. We sought to review current practices and barriers to brain health guidance in a regional integrated care outreach programme (ICOP). Methods From March–June’21 the comprehensive geriatric assessment (CGA) of consecutive patients were reviewed. Those presenting with cognitive complaints, for their first assessment, were included. Demographic data and data on screening for hearing impairment and sleep disturbance were collected, in addition to information on physical activity and nutritional risk. Whether information and guidance on aspects of brain health was given was also assessed. Results 30 patients met the inclusion criteria. The mean age was 80.3 and the mean clinical frailty scale (CFS) was 4.4. Hearing impairment was present in 20% (n = 6), with no information available in 10% (n = 3). All patients were screened for sleep disturbance, with 13% (n = 4) not fully satisfied with their sleep. Mobility aids, assistance or supervision were required in 40% (n = 12), and 23% (n = 7) were at medium or high malnutrition risk. Only 30% (n = 9) cooked their own meals. Generic brain health advice, or advice about sleep was documented in 30 (n = 9), without hearing impairment advice documented in any patient. Conclusion There are several barriers to brain health advice in the ICOP setting, with only 30% of patients having brain health advice documented. We are currently developing patient information leaflets on brain health, that will take potential barriers into account. Dedicated and specific information on local hearing services is also in development, as part of an ongoing quality improvement project.

Background Sleep disturbance is common in the older patient, and has been associated with many common comorbidities, falls, impaired quality of life, and mortality. Sleep disturbance screening and management are important elements of the comprehensive geriatric assessment (CGA). There are few sleep disturbance assessment tools, however, that have been validated for use in older patients, or in those with cognitive impairment. We sought to review the assessment and management of sleep disturbance within a regional integrated care outreach programme (ICOP), where the RU-SATED tool had been used. Methods From March–June’21 the notes of 30 consecutive patients, presenting to ICOP with cognitive complaints, were reviewed. Demographic and sleep disturbance data were collected, in addition to whether advice, treatment or further assessment for sleep disturbance was documented. Feedback from staff on the utility of the RU-SATED tool was also sought. Results Of those reviewed, the mean age was 80.3 (SD = 7.8), and the mean Montreal Cognitive Assessment score (MOCA) was 17.7 (SD = 5.9). Where data was available, the mean RU-SATED score was 7.6 (SD = 1.9), and 42% were frail (n = 11). The most commonly endorsed sleep symptom was sleep onset latency/sleep maintenance issues (n = 16). RU-SATED score did not significantly predict age, MOCA or frailty (p > 0.1 for all). Advice, treatment or further assessment of sleep disturbance was offered to 23% of patients (n = 7), and this was not predicted by overall RU-SATED score or by individual question responses (p > 0.1 for all). Staff also stated that they found elements of the tool difficult to explain and interpret. Conclusion Although the numbers are small, we have not found the RU-SATED tool to be helpful in guiding the management of sleep disturbance in our cohort. A more practical CGA tool is currently in development by the ICOP service.

Background Home support services aim to support older people to remain at home. Despite substantial investment in home support hours (€600 million), this has not translated into increased carers on the ground for older people. We aimed to report patterns of home support service utilisation in older patients with memory problems, and identify any mis-matches between allocated and received hours, and the impact on patients and caregivers. Methods Retrospective analysis of consecutive patients referred to community geriatric clinic from January 2021 to May 2022. 95/104 patients who were identified were suitable for inclusion. Results Participants had a median age of 82 (IQR 78-86) of whom 57% were female (n=54). 80% (n=76) were frail (CFS ≥4), with 82% dependent for IADLs (Lawton-Brody IADL Scale ≤6). Median MOCA score was 18, with 44% having moderate to severe cognitive impairment (MOCA ≤17). 40% of patients lived with alone (n=38). 52% (n=49) received formal home supports while 80% (n=76) had an informal carer. 37% (n=18) had a mismatch between hours allocated and hours received. There was a significant difference between median hours of care allocated (7) and median hours of care received (5), p Conclusion In this vulnerable population with cognitive and functional decline, just over half received formal home support hours. A large proportion experienced significant mismatch between allocated and received hours. Family and informal caregivers often have to fill gaps, adding to existing carer strain. Future models of home support should prioritise early intervention for people with IADL loss to remain independent at home and broaden of the scope of practice of carers to facilitate this.

Background The Frailty at the Front Door service is a novel service that provides comprehensive geriatric assessment in the emergency department for older adults who have an unplanned emergency presentation to hospital. It is important to monitor outcomes of patients discharged by the service to ensure appropriate patient selection. Methods Patients over the age of 75 with a Manchester Triage Score of between three and five and a possible frailty syndrome are eligible for review by the service. After initial review patients are either discharged directly or recommended for admission. We reviewed the outcomes of patients who were discharged directly after Emergency Department (ED) assessment by the service. Results Discharge disposition was available for review in 413 (95%) of patients since initiation of the service in October 2021. 30% (n= 122) of patients were discharged directly after initial ED review. Elevated 4AT score (p = 0.002) but not frailty (p = 0.80) was associated with decreased chances of direct discharge. Of patients discharged directly from ED 13% were reviewed post discharge by the community integrated care team (GICOP), with 43% of these reviews taking place within 30 days. Overall, 16% of patients discharged directly represented to ED within 30 days. There was a trend towards lower rates of representation to ED among patients who were seen by GICOP after discharge from ED (p = 0.12). Conclusion There was a high rate of direct discharge after review by the service, with low rates of representation to hospital. While limited by low numbers there was a trend towards lower representation rates in patients reviewed post-discharge by the integrated care team. Future quality improvement initiatives will aim to improve the integration between the services and highlighting patients who would benefit from more timely reviews.

Background Comprehensive Geriatric Assessment (CGA) is a cornerstone in geriatric care. Objective findings from CGA may differ to patient and carer reported symptoms. This study compared patient reported symptoms with objective metrics collected during CGA and explored the relationship with carer burnout. Methods Cross-sectional study of patients attending an Advanced Nurse Practitioner (ANP)-led integrated care clinic. Patient-reported geriatric syndromes included low mood, memory concerns, incontinence, falls or dizziness. CGA metrics collected included Barthel Index, Lawton IADLs, MOCA scores, Geriatric depression scale scores, Rockwood Clinical Frailty Scale (CFS) scores and presence or absence of carer burnout. Descriptive statistics were used to compare the relationship between these variables and logistic regression explored the magnitude of association with carer burnout. Results We reviewed 99 CGAs over three months. Median age was 81 (IQR 75–86) with 62% female. Cognitive impairment was present in 96% of patients. Self-reported memory trouble was associated with lower MOCA scores (9 vs 23, p < 0.001) and the presence of dizziness was associated with an increased prevalence of falls (89% vs 24%, < 0.001). The presence of incontinence and functional dependency on IADL were both associated with carer strain and a larger magnitude of association with carer strain was seen with increasing frailty (OR 13.7, 95% CI 3.8-58.8 for moderate to severe frailty) than moderate to severe cognitive impairment (OR 8, 95% CI 3.0–24.1) Conclusion Older people reported a wide range of symptoms often subtle, some of which are unmasked during CGA. The resultant frailty syndromes often represent increasing degrees of functional impairment impacting on patient and carer quality of life. Striking the balance between patient reported symptoms and objective measurement is important to allow individualised care pathways to be developed as well as highlighting patients at risk of functional and cognitive decline.

Purpose The development of collimating technologies has become a recent focus in pencil beam scanning (PBS) proton therapy to improve the target conformity and healthy tissue sparing through field-specific or energy-layer–specific collimation. Given the growing popularity of collimators for low-energy treatments, the purpose of this work was to summarize the recent literature that has focused on the efficacy of collimators for PBS and highlight the development of clinical and preclinical collimators. Materials and Methods The collimators presented in this work were organized into 3 categories: per-field apertures, multileaf collimators (MLCs), and sliding-bar collimators. For each case, the system design and planning methodologies are summarized and intercompared from their existing literature. Energy-specific collimation is still a new paradigm in PBS and the 2 specific collimators tailored toward PBS are presented including the dynamic collimation system (DCS) and the Mevion Adaptive Aperture. Results Collimation during PBS can improve the target conformity and associated healthy tissue and critical structure avoidance. Between energy-specific collimators and static apertures, static apertures have the poorest dose conformity owing to collimating only the largest projection of a target in the beam's eye view but still provide an improvement over uncollimated treatments. While an external collimator increases secondary neutron production, the benefit of collimating the primary beam appears to outweigh the risk. The greatest benefit has been observed for low- energy treatment sites. Conclusion The consensus from current literature supports the use of external collimators in PBS under certain conditions, namely low-energy treatments or where the nominal spot size is large. While many recent studies paint a supportive picture, it is also important to understand the limitations of collimation in PBS that are specific to each collimator type. The emergence and paradigm of energy-specific collimation holds many promises for PBS proton therapy.

Purpose The aim of this work was to develop and experimentally validate a Dynamic Collimation Monte Carlo (DCMC) simulation package specifically designed for the simulation of collimators in pencil beam scanning proton therapy (PBS-PT). The DCMC package was developed using the TOPAS Monte Carlo platform and consists of a generalized PBS source model and collimator component extensions. Methods A divergent point-source model of the IBA dedicated nozzle (DN) at the Miami Cancer Institute (MCI) was created and validated against on-axis commissioning measurements taken at MCI. The beamline optics were mathematically incorporated into the source to model beamlet deflections in the X and Y directions at the respective magnet planes. Off-axis measurements taken at multiple planes in air were used to validate both the off-axis spot size and divergence of the source model. The DCS trimmers were modeled and incorporated as TOPAS geometry extensions that linearly translate and rotate about the bending magnets. To validate the collimator model, a series of integral depth dose (IDD) and lateral profile measurements were acquired at MCI and used to benchmark the DCMC performance for modeling both pristine and range shifted beamlets. The water equivalent thickness (WET) of the range shifter was determined by quantifying the shift in the depth of the 80% dose point distal to the Bragg peak between the range shifted and pristine uncollimated beams. Results A source model of the IBA DN system was successfully commissioned against on- and off-axis IDD and lateral profile measurements performed at MCI. The divergence of the source model was matched through an optimization of the source-to-axis distance and comparison against in-air spot profiles. The DCS model was then benchmarked against collimated IDD and in-air and in-phantom lateral profile measurements. Gamma analysis was used to evaluate the agreement between measured and simulated lateral profiles and IDDs with 1%/1 mm criteria and a 1% dose threshold. For the pristine collimated beams, the average 1%/1 mm gamma pass rates across all collimator configurations investigated were 99.8% for IDDs and 97.6% and 95.2% for in-air and in-phantom lateral profiles. All range shifted collimated IDDs passed at 100% while in-air and in-phantom lateral profiles had average pass rates of 99.1% and 99.8%, respectively. The measured and simulated WET of the polyethylene range shifter was determined to be 40.9 and 41.0 mm, respectively. Conclusions We have developed a TOPAS-based Monte Carlo package for modeling collimators in PBS-PT. This package was then commissioned to model the IBA DN system and DCS located at MCI using both uncollimated and collimated measurements. Validation results demonstrate that the DCMC package can be used to accurately model other aspects of a DCS implementation via simulation.

Background: RNA sequencing (RNA-Seq) allows the characterization of a global transcriptomic signature in a least-biased fashion, but few studies have applied this method to investigate the pathophysiology of CRS. Methods: We collected mucosal tissue samples from 6 CRS without nasal polyps (CRSsNP), 6 CRS with nasal polyps (CRSwNP), and 6 control patients. Additional matched polyp samples were collected from the 6 CRSwNP patients. RNA was extracted and sequenced on the Illumina HiSeq-2500. Differential gene expression and pathway analyses were performed. Results: CRSsNP showed evidence of upregulated interferon-mediated immunity, MHC-class-I mediated antigen presentation, CXCR3 binding, neutrophil chemotaxis and degranulation, and potential downregulation of genes related to cilia movement and production. CRSwNP polyp tissue showed upregulation of B-cell mediated immune responses, but reduced expression of genes related to epithelial morphogenesis and haemostasis. Polyps also showed a generalized reduction of positive gene regulation. The sinonasal transcriptomic signature was largely determined by tissue type (polyp versus mucosa) and disease phenotype, with minimal signal originating from the individual patient. Conclusion: RNA-Seq is a useful tool to explore the complex pathophysiology of CRS. Our findings stress the importance of tissue selection in molecular research utilizing sinonasal tissue, and demonstrate the limitation of the sNP/wNP paradigm (and the importance of endotyping). On the other hand, classical CRSsNP/wNP disease phenotypes played some role in determining the global transcriptomic signature, and should not be hastily discarded. The value of RNA-Seq-described transcriptomic signatures in exploring endotypes is yet to be explored in future studies. Refereed/Peer-reviewed

Purpose When designing a collimation system for pencil beam spot scanning proton therapy, a decision must be made whether or not to rotate, or focus, the collimator to match beamlet deflection as a function of off-axis distance. If the collimator is not focused, the beamlet shape and fluence will vary as a function of off-axis distance due to partial transmission through the collimator. In this work, we quantify the magnitude of these effects and propose a focused dynamic collimation system (DCS) for use in proton therapy spot scanning. Methods This study was done in silico using a model of the Miami Cancer Institute's (MCI) IBA Proteus Plus system created in Geant4-based TOPAS. The DCS utilizes rectangular nickel trimmers mounted on rotating sliders that move in synchrony with the pencil beam to provide focused collimation at the edge of the target. Using a simplified setup of the DCS, simulations were performed at various off-axis locations corresponding to beam deflection angles ranging from 0° to 2.5°. At each off-axis location, focused (trimmer rotated) and unfocused (trimmer not rotated) simulations were performed. In all simulations, a 4 cm water equivalent thickness range shifter was placed upstream of the collimator, and a voxelized water phantom that scored dose was placed downstream, each with 4 cm airgaps. Results Increasing the beam deflection angle for an unfocused trimmer caused the collimated edge of the beamlet profile to shift 0.08-0.61 mm from the baseline 0° simulation. There was also an increase in low-dose regions on the collimated edge ranging from 14.6% to 192.4%. Lastly, the maximum dose, D max , was 0-5% higher for the unfocused simulations. With a focused trimmer design, the profile shift and dose increases were all eliminated. Conclusions We have shown that focusing a collimator in spot scanning proton therapy reduces dose at the collimated edge compared to conventional, unfocused collimation devices and presented a simple, mechanical design for achieving focusing for a range of source-to-collimator distances.

PURPOSE: The radiobiological benefits afforded by spatially fractionated (GRID) radiation therapy pairs well with the dosimetric advantages of proton therapy. Inspired by the emergence of energy-layer specific collimators in pencil beam scanning (PBS), this work investigates how the spot spacing and collimation can be optimized to maximize the therapeutic gains of a GRID treatment while demonstrating the integration of a dynamic collimation system (DCS) within a commercial beam line to deliver GRID treatments and experimentally benchmark Monte Carlo calculation methods. METHODS: GRID profiles were experimentally benchmarked using a clinical DCS prototype that was mounted to the nozzle of the IBA Dedicated Nozzle system. Integral depth dose (IDD) curves and lateral profiles were measured for uncollimated and GRID-collimated beamlets. A library of collimated GRID dose distributions were simulated by placing beamlets within a specified uniform grid and weighting the beamlets to achieve a volume-averaged tumor cell survival equivalent to an open field delivery. The healthy tissue sparing afforded by the GRID distribution was then estimated across a range of spot spacings and collimation widths, which were later optimized based on the radiosensitivity of the tumor cell line and the nominal spot size of the PBS system. This was accomplished by using validated models of the IBA Universal and Dedicated nozzles. RESULTS: Excellent agreement was observed between the measured and simulated profiles. The IDDs matched above 98.7% when analyzed using a 1%/1 mm gamma criteria with some minor deviation observed near the Bragg peak for higher beamlet energies. Lateral profile distributions predicted using Monte Carlo methods agreed well with the measured profiles; a gamma passing rate of 95% or higher was observed for all in-depth profiles examined using a 3%/2 mm criteria. Additional collimation was shown to improve PBS GRID treatments by sharpening the lateral penumbra of the beamlets but creates a tradeoff between enhancing the valley-to-peak ratio of the GRID delivery and the dose-volume effect. The optimal collimation width and spot spacing changed as a function of the tumor cell radiosensitivity, dose, and spot size. In general, a spot spacing below 2.0 cm with a collimation less than 1.0 cm provided a superior dose distribution among the specific cases studied. CONCLUSIONS: The ability to customize a GRID dose distribution using different collimation sizes and spot spacings is a useful advantage, especially to maximize the overall therapeutic benefit. In this regard, the capabilities of the DCS, and perhaps alternative dynamic collimators, can be used to enhance GRID treatments. Physical dose models calculated using Monte Carlo methods were experimentally benchmarked in water and were found to accurately predict the respective dose distributions of uncollimated and DCS-collimated GRID profiles.

Objective. Pencil beam scanning (PBS) proton therapy target dose conformity can be improved with energy layer-specific collimation. One such collimator is the dynamic collimation system (DCS), which consists of four nickel trimmer blades that intercept the scanning beam as it approaches the lateral extent of the target. While the dosimetric benefits of the DCS have been demonstrated through computational treatment planning studies, there has yet to be experimental verification of these benefits for composite multi-energy layer fields. The objective of this work is to dosimetrically characterize and experimentally validate the delivery of dynamically collimated proton therapy with the DCS equipped to a clinical PBS system. Approach. Optimized single field, uniform dose treatment plans for 3 × 3 × 3 cm3 target volumes were generated using Monte Carlo dose calculations with depths ranging from 5 to 15 cm, trimmer-to-surface distances ranging from 5 to 18.15 cm, with and without a 4 cm thick polyethylene range shifter. Treatment plans were then delivered to a water phantom using a prototype DCS and an IBA dedicated nozzle system and measured with a Zebra multilayer ionization chamber, a MatriXX PT ionization chamber array, and Gafchromic™ EBT3 film. Main results. For measurements made within the SOBPs, average 2D gamma pass rates exceeded 98.5% for the MatriXX PT and 96.5% for film at the 2%/2 mm criterion across all measured uncollimated and collimated plans, respectively. For verification of the penumbra width reduction with collimation, film agreed with Monte Carlo with differences within 0.3 mm on average compared to 0.9 mm for the MatriXX PT. Significance. We have experimentally verified the delivery of DCS-collimated fields using a clinical PBS system and commonly available dosimeters and have also identified potential weaknesses for dosimeters subject to steep dose gradients.

Liquid desiccant dehumidification is one of the energy-efficient alternatives to conventional air conditioning systems for humidity control. Membrane dehumidifier is preferred to avoid the desiccant carryover, which occurs in a conventional packed bed dehumidifier. However, its mass transfer performance is lesser than that of the packed bed dehumidifier. This is due to additional mass transfer resistance of the membrane between the air and desiccant. It is found that the resistance by the boundary layer formed at the membrane-air interface accounts for a significant portion of the overall mass transfer resistance. Breaking of such boundary layer using ultrasound is an attractive technique to reduce the resistance. The present study experimentally investigates the influence of ultrasound on the mass transfer performance of a membrane humidifier. Subsequently, with the experimental results of the humidifier, the effect of ultrasound on the performance of the membrane dehumidifier is numerically studied. The performances of humidifier and dehumidifier are presented in terms of moisture addition or removal rate and latent effectiveness. It is found that the vibration due to ultrasound enhances the performance of the membrane dehumidifier by 1.5 times.

The aim of this work was to use TOPAS Monte Carlo simulations to model the effect of magnetic fields on dose distributions in brachytherapy lung treatments, under ideal and clinical conditions. Idealistic studies were modeled consisting of either a monoenergetic electron source of 432 keV, or a polyenergetic electron source using the spectrum of secondary electrons produced by 192Ir gamma-ray irradiation. The electron source was positioned in the center of a homogeneous, lung tissue phantom (ρ = 0.26 g/cm3). Conversely, the clinical study was simulated using the VariSource VS2000 192Ir source in a patient with a lung tumor. Three contoured volumes were considered: the tumor, the planning tumor volume (PTV), and the lung. In all studies, dose distributions were calculated in the presence or absence of a constant magnetic field of 3T. Also, TG-43 parameters were calculated for the VariSource and compared with published data from EGS-brachy (EGSnrc) and PENELOPE. The magnetic field affected the dose distributions in the idealistic studies. For the monoenergetic and poly-energetic studies, the radial distance of the 10% iso-dose line was reduced in the presence of the magnetic field by 64.9% and 24.6%, respectively. For the clinical study, the magnetic field caused differences of 10% on average in the patient dose distributions. Nevertheless, differences in dose-volume histograms were below 2%. Finally, for TG-43 parameters, the dose-rate constant from TOPAS differed by 0.09% ± 0.33% and 0.18% ± 0.33% with respect to EGS-brachy and PENELOPE, respectively. The geometry and anisotropy functions differed within 1.2% ± 1.1%, and within 0.0% ± 0.3%, respectively. The Lorentz forces inside a 3T magnetic resonance machine during 192Ir brachytherapy treatment of the lung are not large enough to affect the tumor dose distributions significantly, as expected. Nevertheless, large local differences were found in the lung tissue. Applications of this effect are therefore limited by the fact that meaningful differences appeared only in regions containing air, which is not abundant inside the human.

Vapor chambers and heat pipes are often used as standalone heat spreaders for electronics cooling and in other applications. Metal additive manufacturing (AM) techniques have an intrinsic ability to form the porous structures and internal cavities required to fabricate a vapor chamber or a heat pipe. Additive manufacturing techniques thereby have potential for fabricating vapor chambers with complex geometries and locally tailored wick structures to improve performance as well as to monolithically embed vapor chamber heat spreaders within other components. The focus of the present work is to conduct an experimental assessment of the viability of additively manufactured vapor chambers. A direct metal laser sintering (DMLS) technique was used to fabricate a monolithic stainless steel vapor chamber heat spreader with a 39% porous, 0.5-mm thick wick and a 1.5-mm thick internal vapor core. The functionality of the as-printed vapor chamber was evaluated based on characterization of the heat spreading behavior with and without fluid charge. Charging with water decreased the effective thermal resistance of the device while spreading heat from a central hot spot, confirming functionality of the additively manufactured vapor chamber.

Air conditioning and refrigeration systems account for almost half of the energy consumption in buildings of the developed countries. The liquid sorption system is a promising alternative to the conventional vapor compression system which is energy inefficient. It is classified into open (dehumidification) and closed (absorption) systems which are used to control the humidity of air and temperature of the cooling stream respectively. The present study proposes a new hybrid system that integrates the absorption refrigeration system with a membrane dehumidifier for air conditioning and refrigeration. The proposed system also produces potable water from ambient humidity. It is viable only with the membrane dehumidifier since its microporous membrane avoids the direct contact between the air and solution streams but allows heat and mass transfer between them. As a result, the vacuum pressure of the proposed system remains unaltered. Moreover, the corrosion in the proposed (due to traces of air) and air handling systems (due to traces of solution) is avoided. In the present study, the performance of the proposed system is compared with the conventional absorption refrigeration system and also investigated under the influence of the design and operating parameters, and ambient conditions. Performance analysis found that the proposed system produces the air with 2.6 kW cooling capacity and 0.00102 kg/s potable water from the given evaporator load of 10 kW for the hot and humid climatic conditions.

Air conditioning (AC) systems demand a significant portion of the total energy consumed by the building sector. Conventional AC based on vapor compression refrigeration (VCR) is neither energy efficient nor environment-friendly due to its method of humidity control and use of refrigerants with global warming potential respectively. Liquid desiccant air conditioning system (LDAS) is a promising alternative to VCR. This review provides a comprehensive overview of the developments in LDAS so far. It explains the principle of operation and classification in detail. The various developments in dehumidifier, regenerator, desiccant material, and mathematical modelling are discussed. The various types of performance parameters, and the design criteria and effect of operating parameters are also detailed. Finally, the climate feasibility, performance control strategies and indoor air quality are explained. This communication will be useful to identify the research gaps to explore new pathways for future research to further improve the efficiency of LDAS.

Problem statement: Hepatic-only metastasis in colorectal cancer is not a rare clinical finding and can account for 30% of cases. However, only 10-25% of cases are suitable for hepatic resection as part of their treatment pathway. We sought to document our own findings by reviewing patients with hepatic-only disease. Approach: A retrospective analysis was designed to include all patients seen at our institution from 1st January 2000 until 30th June 2010 and information as derived from the patients’ records. Results: Forty-four (44) patients were found, with an average age of 60.8 years and a male preponderance. The majority of patients (approximately 57%) with hepatic-only metastases developed their disease following adjuvant therapy. Better overall survival was seen when a primary tumor had a low grade of histological differentiation and fewer than 3 hepatic lesions appreciated on conventional radiology. Better outcome was seen in patients who underwent hepatic resection. Conclusion: Patients with hepatic-only metastases are not uncommon within our institution. Hepatic resection afforded better outcome and compares favorably with published literature.

Hypotensive resuscitation in the trauma setting can be defined as deliberately allowing blood pressure to remain below normal until any active bleeding has been controlled. The dangers of aggressive fluid resuscitation in trauma were recognised as long ago as the First World War, in the intervening time, aggressive fluid resuscitation has become a mainstay of trauma management. More recently this trend of aggressive fluid resuscitation for trauma management seems to be reversing. Aggressive fluid resuscitation in trauma is based on animal studies from the 1950s and 1960s. These studies used models of controlled haemorrhage rather than uncontrolled haemorrhage. More recent studies using models of uncontrolled haemorrhage suggest an improved outcome with hypotensive resuscitation. Should there be a potential for uncontrolled haemorrhage a permissive hypotensive resuscitation strategy should be pursued until the haemorrhage has been controlled, but in certain types of trauma including blunt trauma and brain trauma the data is unclear as to the best fluid resuscitation strategy.

Void fraction remains a crucial parameter in understanding and characterizing two-phase flow. It appears as a key variable in both heat transfer and pressure drop correlations of two-phase flows, from the macro to micro-channel scale. Void fraction estimation dictates the sizing of both evaporating and condensing phase change heat exchangers, for example. In order to measure void fraction some invasive approach is necessary. Typically, visualization is achieved either downstream of the test section or on top by machining to expose the channel. Both approaches can lead to inaccuracies. The former assumes the flow will not be affected moving from the heat exchanger surface to the transparent section. The latter distorts the heat flow path. Neutron Imaging can provide a non-invasive measurement because metals such as Aluminum are essentially transparent to neutrons. Hence, if a refrigerant is selected that provides suitable neutron attenuation; steady-state void fraction measurements in two-phase flow are attainable in-situ without disturbing the fluid flow or heat flow path. Neutron Imaging has been used in the past to qualitatively describe the flow in heat exchangers in terms of maldistributions without providing void fraction data. This work is distinguished from previous efforts because the heat exchanger has been designed and the refrigerant selected to avail of neutron imaging. This work describes the experimental flow loop that enables a boiling two-phase flow; the heat exchanger test section and downstream transparent section are described. The flow loop controls the degree of subcooling and the refrigerant flowrate. Heating cartridges embedded in the test section are employed to control the heat input. Neutron-imaged steady-state void fraction measurements are captured and compared to representative high-speed videography captured at the visualization section. This allows a qualitative comparison between neutron imaged and traditional techniques. The measurements are also compared to correlations in the literature. Preliminary void fraction images from a macro-channel flow are presented, consisting of 1 channel, 4mm wide, 4mm high and 83.32mm long. Flow regime identification is examined. The experiments were conducted at the High Flux Isotope Reactor (HFIR) Cold Guide 1D neutron imaging facility at Oak Ridge National Laboratory, Oak Ridge, TN, USA.

Solid oxide fuel cell (SOFC)/ gas turbine (GT) hybrid systems possess the capacity for unprecedented performances, such as electric efficiencies nearly twice that of conventional heat engines at variable scale power ratings inclusive of distributed generation. Additionally, these hybrids can have excellent operational flexibility with turndowns possibly as great as 85%. There are, however, developmental needs such as turbomachinery characterization and re-design. A leading example is that of greater propensity to have occurrences of stall-surge given the significantly different operating environment in contrast to conventional heat engines. Additionally, dynamic variation in power generation has to be done with significant a priori insight to avoid thermomechanical threats to cell stack and turbomachinery. State-of-the-art approaches involving hardware-in-the-loop simulation and, ultimately, additive manufacturing are being pursued to enable such characterization and re-design considerations given variable and dynamic operability requirements. Compressor performance in hybrid systems has been characterized at the United States National Energy Technology Laboratory (NETL), inclusive of a capability of feed forward hardware-in-the-loop simulation of hybrid systems under dynamic conditions and a capability of replacing turbine and compressor components at a relatively low cost. This paper highlights some of the simulation results, and the net result is an approach that addresses hybrid system developmental needs for accommodating generation transients.

This paper presents an analytical method for evaluating the reliability improvement for any size of multi-computer system based on Software-Implemented Fault-Tolerance (SIFT). The method is based on the equivalent failure rate Gamma, the single node failure rate lambda, the number of nodes in the system, N, the repair rate mu, the fault coverage factor c, the reconfiguration rate delta, and the percentage of blocking faults b1 and b2. The impact of these parameters on the reliability improvement has been evaluated for a gracefully degradable multi-computer system using our proposed analytical technique based on Markov chains. To validate our approach, we used the SIFT method which implements error detection at the node level, combined with a fast reconfiguration algorithm for avoiding faulty nodes. It is worth noting that the proposed method is applicable to any multi-computer systems' topology. The evaluation work presented in this paper focuses on the combination of analytical and experimental approaches, and more precisely on Markov chains. The SIFT method has been successfully implemented for a multi-computer system, nCube. The time overhead (reconfiguration & recomputation time) incurred by the injected fault, and the fault coverage factor c, are experimentally evaluated by means of a parallel version of the Software Object-Oriented Fault-Injection Tool (nSOFIT). The implemented SIFT approach can be used for real-time applications, when the time constraints should be met despite failures in the gracefully degradable multi-computer system

Objectives To describe the maternal tolerability of nevirapine as part of combination antiretroviral therapy in pregnancy at three HIV centres in Dublin, Ireland and to determine risk factors for development of significant hepatotoxicity. Methods A retrospective study was carried out of all women prescribed nevirapine as part of combination antiretroviral therapy in pregnancy at three HIV centres in Dublin, Ireland (October 2000 to February 2003). Toxicities experienced were graded according to the Division of AIDS toxicity guidelines for adults. Statistical analysis was performed to determine whether there were differences between those that did and those that did not experience significant hepatotoxicity. Results A total of 123 women initiated nevirapine as part of combination antiretroviral therapy in the study period. Eight women developed significant hepatotoxicity, including two women who died from fulminant hepatitis. Women who experienced more severe hepatotoxicity had higher pretreatment CD4 counts (P=0.01). Conclusions In this cohort, women who experienced more severe hepatotoxicity had higher pretreatment CD4 counts, lending additional weight to the need for caution in using nevirapine as part of combination antiretroviral therapy in women not requiring antiretroviral therapy for their own health.

The development of moxidectin resistance (MOX-R) in sheep parasitic gastrointestinal nematodes already carrying multiple resistances to other anthelmintic groups has made control of these strains very difficult. The anthelmintic resistance patterns of MOX-R strains of Trichostrongylus colubriformis and Haemonchus contortus were characterized to provide an insight into the remaining role of anthelmintics in the control of such strains. Homozygous MOX-R individuals of both genera were unaffected by moxidectin. For MOX-R heterozygotes a dose rate of 200 microg/kg abamectin (ABA) given orally removed 25% of H. contortus while 200 microg/kg MOX given orally achieved a 72% reduction. Doubling the dose rate of ABA improved the mean efficacy to 37%. Consequently, in H. contortus, the degree of dominance differs markedly between the two anthelmintics. A dose rate of 8 mg/kg levamisole and 185 mg/kg napthalophos achieved95% reduction in worm count of the MOX-R homozygous H. contortus but only 85 and 7%, respectively against the MOX-R homozygous T. colubriformis.

We present a case of a young boy with an unusual cause of right iliac fossa pain. His history, examination and laboratory investigations suggested a diagnosis of acute appendicitis. However preoperative abdominal CT revealed an inflamed solitary caecal diverticulum and a normal appendix. He was subsequently treated conservatively and recovered well, saving him from undergoing a general anaesthetic and abdominal surgery.

Pressure waves created in liquid mercury targets at the pulsed Spallation Neutron Source (SNS) at Oak Ridge National Laboratory induce cavitation damage on the stainless steel target vessel. The cavitation damage is thought to limit the lifetime of the target for power levels at and above 1 MW. Severe through-wall cavitation damage on an internal wall near the beam entrance window has been observed in spent-targets. Surprisingly though, there is very little damage on the walls that bound an annular mercury channel that wraps around the front and outside of the target. The mercury flow through this channel is characterized by smooth, attached streamlines. One theory to explain this lack of damage is that the uni-directional flow biases the direction of the collapsing cavitation bubble, reducing the impact pressure and subsequent damage. The theory has been reinforced by in-beam separate effects data. For this reason, a second-generation SNS mercury target has been designed with an internal wall jet configuration intended to protect the concave wall where damage has been observed. The wall jet mimics the annular flow channel streamlines, but since the jet is bounded on only one side, the momentum is gradually diffused by the bulk flow interactions as it progresses around the cicular path of the target nose. Numerical simulations of the flow through this jet-flow target have been completed, and a water loop has been assembled with a transparent test target in order to visualize and measure the flow field. This paper presents the wall jet simulation results, as well as early experimental data from the test loop.Copyright © 2014 by ASME

We investigated whether the increase in epidural pressure produced by jugular compression could be used as a test for correct placement of epidural catheters in 20 postpartum women who had good epidural analgesia during labour. We measured the epidural pressure by using the epidural catheter as a manometer, and measured the rise in the meniscus in response to jugular vein compression whilst the epidural catheter was still in the epidural space. The catheter was then withdrawn until the tip lay just outside the epidural space and the response to jugular vein compression reassessed. In all subjects, jugular vein compression produced a rise in the meniscus only whilst the catheter tip lay in the epidural space. Jugular compression is a useful test for confirming the correct placement of the epidural catheter.

We propose a systematic approach for design and validation of error detection software. Formally, the semantic of a specification is represented by a transition system. This representation is then used to generate a flowgraph or ddgraph which is used to construct an execution path tree. The information obtained from this algorithm representation is used to aid in the design of software-based fault detection techniques for hardware faults. Flowgraph and ddgraph representations provide information to predict future program flow. During execution, the current program path is recorded, along with the expected path. Checks are placed to verify that the program path follows the predicted path. Algorithm-based fault tolerance (ABFT) techniques are used to detect data structure corrupting faults and to improve the fault coverage. Fault coverage provided by this approach for different types of hardware faults has been estimated through experiments with the software-based fault injection tool (SOFIT) and the data is presented to demonstrate the effectiveness of the method.

The effect of a uniform magnetic field applied at an oblique angle to the easy axis of magnetization on the superparamagnetic ~longitudinal or Neel! relaxation time is investigated by numerically solving the Fokker- Planck equation for the smallest nonvanishing eigenvalue. It is demonstrated that the reciprocal of the asymptotic formula for the Kramers escape rate in the intermediate to high damping limit for general nonaxi- ally symmetric potentials when applied to the present problem, yields an acceptable asymptotic approximation to the Neel time for moderate to high values of the damping. Alternatively the corresponding Kramers low dissipation formula ~energy controlled diffusion! provides an acceptable approximation for very small values of the damping. The effect of the gyromagnetic term which gives rise to coupling between the longitudinal and transverse modes of motion generally corresponds to an increase of the smallest nonvanishing eigenvalue and so to a decrease of the Neel relaxation time. The integral relaxation time or area under the slope of the curve of the decay of the magnetization is also evaluated. It is demonstrated that for sufficiently high values of the uniform field ~much less, however, than that required to destroy the bistable nature of the potential ! the reciprocal of the lowest nonvanishing eigenvalue ~proportional to the Neel time, or the time of reversal of the magnetization! and the integral relaxation time may differ exponentially from one another signifying the contributions of modes other than that associated with the overbarrier ~Neel! relaxation process to the overall relaxation process. The overall behavior is qualitatively similar ~apart from the azimuthal dependence! to that of the axially symmetric case which arises due to the depletion of the shallower of the two potential wells by the uniform field, so that the fast processes in the deeper of the two wells may come to dominate the relaxation process at sufficiently high values of the uniform field.@S0163-1829~98!04229-5#

The effect of a uniform magnetic field applied at an oblique angle ψ to the easy axis of magnetization on the superparamagnetic (longitudinal or Neel) relaxation time is illustrated by considering the simplest possible case where the field is applied normal to the easy axis. This is accomplished by numerically solving the Fokker-Planck equation for the smallest non-vanishing eigenvalue λ 1 . It is demonstrated that the asymptotic formula for the Kramers escape rate for general non-axially symmetric potentials evaluated for the particular case ψ = π /2 yields an acceptable asymptotic approximation to the behaviour of λ 1 for sufficiently high-potential barrier heights and a wide range of values of the dimensionless damping factor. The effect of the gyromagnetic term which gives rise to coupling between the longitudinal and transverse modes of motion corresponds to an increase (higher when the dimensionless damping factor a is smaller) of the smallest non-vanishing eigenvalue λ 1 and so to a decrease of the Neel relaxation time τ.

Background: Gastrointestinal stromal tumours (GISTs) are unique neoplasms of the gastrointestinal (GI) tract. The development of targeted therapeutic agents such as imatinib mesylate (Glivec) has altered the way on how we now manage these rare malignancies. The aim of this study was to evaluate the management of GISTs in three Irish tertiary hospitals. Methods: We performed a retrospective, multicenter audit of patients diagnosed with gastrointestinal stromal tumours over a ten year period (2005-2015). Results: 110 patients were included in the study. Abdominal pain was the most common presenting symptom, reported in 30% of patients, while 31% were incidental findings. The stomach was the most common primary site of disease, observed in 77% of cases. 15 patients had metastatic disease at the time of diagnosis (14%), and 10 of these patients had liver involvement. More than half of patients (61%) were managed with surgical excision alone (61%), while 24 were managed with surveillance and 28 patients treated with adjuvant Glivec, which was generally well tolerated. 18 patients (20%) demonstrated recurrent or progressive disease after first line treatment. 102 patients (93%) are alive today. Conclusion: While surgery is widely regarded as the primary treatment modality for GISTs the addition of imatinib mesylate has enabled physicians to deliver more personalised treatment while optimising patient outcomes.

A 43-year-old Caucasian gentleman became confused and agitated while attending a soccer match. He collapsed and was resuscitated by paramedics on the scene. He recovered promptly with intravenous fluid and dextrose. The patient subsequently reported a 6-month history of recurrent spells of sweating, agitation and lethargy suggestive of hypoglycaemia, which typically occurred in the fasting state and were relieved by sugary drinks. Past medical history was relevant for severe eczema from a young age with long-term exposure to highly potent topical steroids. At the time of presentation he was applying up to 100 g of clobetasol 0.05% ointment per month with resultant skin atrophy and spontaneous bruising. He was obese with BMI 35 kg/m2. Assessment of his adrenal reserve with a short synACTHen test was markedly abnormal with a baseline 9am cortisol of 74 nmol/l and 30-min stimulated value of 179 nmol/l (normal >500 nmol/l). Although this result may have explained some of his symptoms and accounted for the episode of collapse, he concurrently underwent a prolonged fast during which he developed symptomatic hypoglycaemia after 28 h. The …