AP Users Research Articles

Association between antithrombotic drug regimen changes and clinical outcomes after stroke in atrial fibrillation

BackgroundThe impact of post-stroke antithrombotic regimen in atrial fibrillation is uncertain. ObjectiveThis study aimed to describe antithrombotic therapy prescribing patterns after ischemic stroke and the impact on outcomes. MethodsA total of 23,165 patients with atrial fibrillation experiencing ischemic stroke were identified. Subsequent post-stroke events included recurrent ischemic stroke, intracranial hemorrhage, major bleeding, mortality, and composite outcomes. ResultsOf those who were nonanticoagulated before a stroke, 33.5% remained nonanticoagulated and 39.2% were prescribed only antiplatelet agents (APs) after a stroke. Compared with non–vitamin K antagonist oral anticoagulants (NOACs) after stroke, there was a significant increase in ischemic stroke and mortality in nonanticoagulated patients (adjusted hazard ratio [aHR], 2.09 and 3.92) and AP users (aHR, 1.32 and 1.28). Post-stroke warfarin was associated with a significantly increased risk of major bleeding compared with NOACs (aHR, 1.23). Of 769 patients receiving NOACs before stroke and continuing NOACs after stroke, those switching to a different NOAC were associated with significantly higher risk of ischemic stroke (aHR, 2.07) and composite outcomes (aHR, 1.36–1.85) with no difference in intracranial hemorrhage, major bleeding, or mortality compared with those receiving the same NOAC after stroke. Of patients receiving NOACs before stroke, the risks of clinical events were similar between patients taking NOACs alone and those taking NOAC plus AP after stroke. ConclusionNOAC alone after stroke was associated with a better clinical outcome compared with nonanticoagulation, AP, or warfarin. Of patients already taking NOACs before stroke, the addition of AP did not confer additional benefits compared with NOACs alone. A change of NOAC types after stroke was associated with a 2-fold higher risk of ischemic stroke and composite outcomes.

Do Antiplatelet Drugs Use Contribute to Clinical Outcomes in Patients Receiving Penile Low- Intensity Shock Wave Therapy (Li-SWT) for Erectile Dysfunction?

Aim: Low-intensity extracorporeal shock wave therapy (Li-SWT) is one of the recommended treatment options in patients with erectile dysfunction (ED). Li-SWT is safe in patients using antiplatelet drugs (APs), however, there are no specific studies on the contribution of APs use to clinical improvement in erectile function. We aimed to evaluate the early clinical results of Li-SWT administration and whether the use of APs had an additional positive contribution to clinical improvement and safe in ED patients.
 Methods: Patients with ED for more than 6 months despite using (5 mg/day) PDE5i were included in our study. Patients treated with Li-SWT and using PDE5i were classified as Group 1, patients treated with Li-SWT and using APs and using PDE5i were considered Group 2. The evaluation results of the International Index of Erectile Function-Erectile Function Area(IIEF-EF) in all patients baseline and after treatment were examined.
 Results: There are 25 patients in each group. Analysis of IIEF-EF scores showed significant increases in both groups after treatment [group 1 (p=0.001); group 2 (p=0.001)]. When the IIEF-EF scores of the groups before and after the treatment were compared with each other; it was shown that baseline scores were similar(p=0.746) and that APs use had no statistically significant effect on post-treatment scores (p=0.613) No side effects were seen in APs.
 Conclusions: This study showed that penile Li-SWT significantly increases the IIEF-EF scores and response of (5 mg/day) PDE5i in ED patients and safe, also in AP users. However, Using AP in Li- SWT does not contribute positively to clinical results.

Thrombotic complications of treatment with antipsychotic drugs : risk factors

Introduction Antipsychotic agents (AP) are widely used drugs to treat psychotic symptoms. For decades, some studies suggested that there is a relationship between using (AP) and the risk of venous thromboembolism (VTE) and pulmonary embolism (PE). The causality of this association, its risk factors, and its implications for clinical practice have not been fully elucidated. Objectives We undertook a systematic literature review to evaluate the evidence for an association between antipsychotic medication and venous thromboembolic events (VTE) and to identify risk factors for these adverse effects. Methods To identify relevant studies, we searched the PubMed, Science Direct databases up using the following keywords « pulmonary embolism », « venous thromboembolism » « antipsychotics agents ». We also searched the reference lists relevant articles for related studies. Results Twelve articles are included in this analysis and indicate an elevated risk of VTE in antipsychotic drug users. The results showed that compared with non-users, current AP users have significantly increased risks of VTE. The risk of venous thrombosis in obese people was higher than that in overweight people, patients not less than 65 years old had an increased risk compared with younger patients . In addition, women taking antipsychotics had a higher risk of pulmonary embolism than men. The other factors that increased risk were use of second-generation antipsychotics and antipsychotic polytherapy. The highest risk was noted in the first 3 months of treatment. Data also suggested a dose-dependent increase in the risk of thrombotic complications. For individual drugs, increased risk of VTE and PE was observed in taking clozapine , haloperidol, risperidone and olanzapine. Clozapine was associated with the highest risk. However, careful interpretation is needed because of high heterogeneity among studies and scarce data. Conclusions The use of antipsychotics will increase the risk of venous thromboembolism and pulmonary embolism, which will be affected by AP and patient characteristics. Disclosure of Interest None Declared

Off-label prescribing of antipsychotics: prescribing practices and clinical experiences of Finnish physicians

IntroductionOff-label use of antipsychotics has increased in many countries. In adult populations antipsychotics off-label prescriptions varied from 40 to 75% of all AP users.ObjectivesTo examine the off-label prescribing practices and experiences of antipsychotic medication in Finland.MethodsAn electronic questionnaire on physicians’ prescription practices of antipsychotics, especially for off-label use, was sent in 2019 for physicians (n=1195) in different health care facilities including primary health care, occupational health care, in- and outpatient mental health services and services for substance abuse. The sample was selected by systematic and convenience sampling covering five university hospital areas in Finland.ResultsIn total, 216 physicians (18% of the target sample) participated in the study, and 94% had prescribed antipsychotics for off-label use. The most common off-label indications were insomnia and anxiety. The most common antipsychotic used was quetiapine. Off-label antipsychotics was not prescribed as a first-choice medication: 99% of the physicians reported that the patients with off-label use have previously had other medications for the corresponding symptoms. In all, 88% of clinicians monitored the patients’ clinical condition, whereas metabolic values were followed more rarely. About 68% of physicians reported more benefit than harm from the antipsychotics off-label use.ConclusionsAntipsychotics are often prescribed for off-label use, most commonly for insomnia and anxiety. Most of the physicians see more benefits than harms for the patient in off-label use. There is a need to analyse the long-term benefits and harms of off-label use of antipsychotics and create more detailed treatment algorithms and clinical recommendations for such use.DisclosureNo significant relationships.

Fabrication and Testing of 18-mm-Period, 0.5-m-Long Nb3Sn Superconducting Undulator

The Advanced Photon Source at Argonne National Laboratory, in collaboration with FNAL and LBNL, is developing a Nb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Sn superconducting undulator with the goal of installing this device on the APS storage ring and providing APS users with the novel radiation source. A series of short, ~8-cm-long, 18-mm-period undulator prototype magnets have been designed, fabricated, and tested. The same design was scaled to fabricate a 0.5-m-long undulator prototype. Tests of this prototype showed that the designed peak magnetic field of 1.2 T at 850 A was successfully achieved. It represents at least a 20% improvement in comparison with a NbTi SCU having the same period and magnetic gap. Test results and lessons learned from the design process are reported.

Prescribing unapproved medical devices? The case of DIY artificial pancreas systems.

In response to slow progress regarding technological innovations to manage type 1 diabetes, some patients have created unregulated do-it-yourself artificial pancreas systems (DIY APS). Yet both in the United Kingdom (UK) and internationally, there is an almost complete lack of specific guidance – legal, regulatory, or ethical – for clinicians caring for DIY APS users. Uncertainty regarding their professional obligations has led to them being cautious about discussing DIY APS with patients, let alone recommending or prescribing them. In this article, we argue that this approach threatens to undermine trust and transparency. Analysing the professional guidance from the UK regulator – the General Medical Council – we demonstrate that nothing within it ought to be interpreted as precluding clinicians from initiating discussions about DIY APS. Moreover, in some circumstances, it may require that clinicians do so. We also argue that the guidance does not preclude clinicians from prescribing such unapproved medical devices.

Antipsychotics and mortality among elderly with dementia: a population based study in the Lazio region

Abstract Background Most dementia patients experience one or more behavioral and psychological symptoms (BPSD) at some time during their illness, in particular in the middle and later stages. Antipsychotic drugs (AP) are often prescribed off-label for treating BPSD, despite concerns about safety and limited efficacy. The impact of AP on short- and long-term mortality has not been fully assessed. Objective To assess the association between the use of APs and short- and long-term mortality in a cohort of dementia patients aged ≥ 65 years residing in the Lazio region. Methods We use data from regional health information systems to conduct a retrospective age, gender and comorbidity matched cohort study with a 1:3 matching ratio to pair dementia patients new AP users with non-users. For the exposed participants, the index date was defined as the date of the first drug prescription; the same date was used for non-users matched subjects. Patients were enrolled on 31/12/2016 and followed-up from the index date through 2018. Four cohorts were enrolled to analyze mortality at 30, 60, 180 and 65 days from the index date. Adjusted estimates were obtained with propensity score matching using the Greedy Nearest Neighbor Matching algorithm. Results We enrolled 34,625 individuals (67% females, mean age 82 years) distributed as follows: 30 days cohort, 4321 users vs 12,960 non-users; 60 days cohort, 4202 users vs 12,606 non-users; 180 days cohort, 3641 users vs 19,923 non-users; 365 days cohort, 2618 users vs 7854 non-users. Multivariate analyses showed a statistically significant excess mortality at 60, 180, and 365 days since the first prescription (HR: 1.83, HR: 1.63, and HR: 1.62, respectively). Conclusions This study showed that antipsychotics increase short- and long-term mortality risk in older adults with dementia. The prescription of AP should be carefully evaluated and, if it is the best option for patient and caregiver, stringently monitored. Key messages Antipsychotic medication use is associated with an increased all-cause mortality in elderly with dementia. The mortality risk increases in 60 days after starting their use and remains elevated at 1 year.

Functional health literacy: protective role in adherence to treatment for hypertensive patients

Objective: To investigate factors associated with Functional Health Literacy (FHL), as well as its role as a probable protective factor for treatment adherence in individuals with hypertension (SAH), attended in Primary Health Care (Atencao Primaria a Saude - APS) units. Methods: This is a cross-sectional study with APS users under antihypertensive medication in the city of Salvador, Bahia. Illiterate or functionally illiterate patients were excluded, as well as those with a history of ischemic stroke. Data were collected between November 2015 and August 2016. Sociodemographic and clinical data were accessed utilizing a structured instrument developed by the authors, and the FHL was assessed using the REALM. Descriptive analyses and logistic regression were performed. Results: The population comprised 286 individuals and it was observed that low schooling was associated with inadequate FHL, both in the gross and adjusted analysis (OR = 9.25; CI95%: 4.49 – 19.05) and with the professional activity of manual labor (OR = 9.90; CI95%: 2.08 – 46.90). In patients with schooling levels of over 8 years, it was observed that the FHL was significantly associated with non-adherence to medical treatment, even after adjustment by gender, age, civil status, physical activity, and skin color (OR = 3.0; CI95%: 1.2 – 7.9). Conclusions: Inadequate FHL was significantly associated with non-adhesion to treatment only for those with over 8 years of schooling. Improvements in health promotion actions should be reinforced to address chronic diseases such as SAH.

Do-It-Yourself Artificial Pancreas Systems: A Review of the Emerging Evidence and Insights for Healthcare Professionals.

Application of artificial pancreas systems in type 1 diabetes (T1D) represents a change in approach to managing complex glucose and insulin dynamics using automated features with higher levels of safety, precision, and reliability than those afforded by manual adjustments. To date, limited commercial systems and more widely used open-source, hybrid closed loop, Do-It-Yourself Artificial Pancreas Systems (DIY APS) have been used in nontrial real-world management of T1D. The aims of this article are twofold. First, itsynthesizes the emerging literature on DIY APS and identifies a range of evidence including research, reviews, commentaries, and opinion pieces written by DIY APS users, healthcare professionals (HCPs), and researchers. It summarizes the emerging clinical evidence for DIY APS and provide insight into how the DIY APS movement began, has been disseminated throughout diabetes online communities, and is reshaping self-management of T1D in real-world settings. Second, the article provides commentaries that explore implications of DIY APS to healthcare practice. DIY APS are radically changing T1D management. Automating the process of frequently analyzing glucose readings and appropriately titrating insulin delivery is liberating people with T1D (PWD) from some of the demands of intensive management. Within this super-specialized area of T1D management, the expertise of DIY APS users has outstripped that of many HCPs. While educational, ethical, and legal constraints need to be resolved, HCPs still need to stay abreast of this rapidly developing area. Further research is needed to inform policy and practice relating to DIY APS. Meanwhile, HCPs continue to learn from PWD's real-world experiences of building and using DIY APS to improve metabolic and psychological outcomes.

Analyzing Transit User Behavior with 51 Weeks of Smart Card Data

A better understanding of mobility behaviors is relevant to many applications in public transportation, from more accurate travel demand models to improved supply adjustment, customized services and integrated pricing. In line with this context, this study mined 51 weeks of smart card (SC) data from Montréal, Canada to analyze interpersonal and intrapersonal variability in the weekly use of public transit. Passengers who used only one type of product (AP − annual pass, MP − monthly pass, or TB − ticket book) over 12 months were selected, amounting to some 200,000 cards. Data was first preprocessed and summarized into card-week vectors to generate a typology of weeks. The most popular weekly patterns were identified for each type of product and further studied at the individual level. Sequences of week clusters were constructed to represent the weekly travel behavior of each user over 51 weeks. They were then segmented by type of product according to an original distance, therefore highlighting the heterogeneity between passengers. Two indicators were also proposed to quantify intrapersonal regularity as the repetition of weekly clusters throughout the weeks. The results revealed MP owners have a more regular and diversified use of public transit. AP users are mainly commuters whereas TB users tend to be more occasional transit users. However, some atypical groups were found for each type of product, for instance users with 4-day work weeks and loyal TB users.

WiFi/LTE-U Coexistence: An Evolutionary Game Approach

We study the spectrum coexistence problem between the long term evolution (LTE)-U and the WiFi technologies using evolutionary game theory. Specifically, we study enabling friendly coexistence mainly by interference reduction through increase in the power transmission cost on each LTE AP 1 (eNodeB) and WiFi AP and find the conditions under which a long-term coexistence can be established. We model this long-term coexistence by finding the evolutionary stable strategies of the evolutionary game. We analyze the cost functions for the LTE-U and the WiFi APs, and show that the LTE-U AP behavior is more sensitive to the cost than to the number of users, while WiFi is more sensitive to the number of users than to the transmission power cost. To further reduce the interference, we consider the case where the WiFi AP removes users that cannot establish the minimum signal to interference plus noise ratio required to reduce the interference to the LTE-U AP users. Interestingly this creates more interference due to the aggressive/selfish behavior of the WiFi APs. Finally, we extend the game over continuous strategies by formulating a game theoretic model for the coexistence problem, find its Nash equilibrium, and study its stability under the replicator dynamics of the evolutionary game. 1 For simplicity, we use the term AP to also refer to LTE-U eNodeBs.

Open Source Closed-Loop Insulin Delivery Systems: A Clash of Cultures or Merging of Diverse Approaches?

Biomedical outcomes for people with diabetes remain suboptimal for many. Psychosocial care in diabetes does not fare any better. "Artificial pancreas" (also known as "closed-loop" and "automated insulin delivery") systems present a promising therapeutic option for people with diabetes (PWD)-simultaneously improving glycemic outcomes, reducing the burden of self-management, and improving health-related quality of life. In recent years there has emerged a growing movement of PWD innovators rallying behind the mantra #WeAreNotWaiting, developing "do-it-yourself artificial pancreas systems (DIY APS)." Self-reported results by DIY APS users show improved metabolic outcomes such as impressive stability of glucose profiles, significant reduction of A1c, and more time within their glycemic target range. However, the benefits remain unclear for the broader population of PWD beyond these highly engaged, highly tech-savvy users willing and able to engage in the demands of building and maintaining their DIY APS. We discuss the challenges faced by key stakeholder groups in terms of potential collaboration and open debate of these challenges.

Rate selection based medium access control for full-duplex asymmetric transmission

The realization of full-duplex wireless communication is predictable. And asymmetric transmission is a practical and low-cost application scenario, where full-duplex access point (FD_AP) can communicate with two users simultaneously to receive and send packets. While, in an asymmetric transmission, the transmit power of uplink sender decides the uplink and downlink rates because of the inter-client interference, which accordingly restricts the throughput. Besides, the size of packets in uplink and downlink is generally unequal. Therefore, a WIFI network with a FD_AP and half-duplex users is studied in this paper, and a medium access control (MAC) protocol based on power control and rate selection (PCRS) is proposed. PCRS MAC employs a received signal strength based rate selection strategy to select different rates and power for uplink and downlink transmission. Then, FD_AP can establish efficient and reliable full-duplex asymmetric transmission. Simulation results show that PCRS can improve the throughput and the probability of successful asymmetric communication as compared to the distributed coordination function (DCF) and a simple full-duplex MAC protocol without PCRS. Besides, PCRS MAC also maintains a high level of fairness.

Exploration of describing the vector-parametric bi-spline, defined by the cubic spline with control points incident with surface of appropriate smoothness

The article proposes description technique for spline vector & parametrical surfaces of the fourth degree with control points incidental to the surface and gives testing examples of application of this technique. Main purpose of researches is to develop an algorithm for solving some application problems which often impose specific demands to tools available with developers’ or designers’ workplace. For instance, it sometime becomes troublesome to produce smooth configuration, since the obtained curve does not belong to pre-set dotted carcass. The technique of producing a vector & parametrical bispline with control points incidental (belonging) to relevant surface is proposed to overcome such inconvenience. Hence, a polynomial function of the fourth degree determined with five points x 0, y 0, x 1, y 1, x 2, y 2, x 3, y 3, x 4, y 4 may be represented, as below: with function α i (u) being the Lagrange polynomial coefficients. Polynomial equation in matrix format may be expressed, as follows: With provided derivatives equity up to the third degree (inclusive) the equity of compound derivatives along the gluing line criterion is also met (i. e. continuity of the second quadric form is achieved throughout the entire surface). Equity of the compound derivatives should be achieved to obtain fine smoothness of the third degree surface, i. e.: Calculation formulae for spline with third degree of smoothness should be applied to achieve this effect. Thus linear equations system with quadrodiagonal leading matrix may be obtained by means of preset three boundary conditions (thus increasing the flexibility of the method) providing a stable and unambiguous solution. Algorithm for development of the fourth degree bispline with control points belonging to relevant surface is developed. Results of the research may be helpful for developers, designers, APS users providing them with additional opportunities in developing smooth curved contours for elements and parts of machinery operating in mobile environments. Test examples are provided for the fourth degree bisplines with third degree smoothness with control points incidental to the surface. The proposed algorithm is suggested for implementation to improve efficient work of constructors, designers, developers.

Mapping axillary microbiota responsible for body odours using a culture-independent approach.

BackgroundHuman axillary odour is commonly attributed to the bacterial degradation of precursors in sweat secretions. To assess the role of bacterial communities in the formation of body odours, we used a culture-independent approach to study axillary skin microbiota and correlated these data with olfactory analysis.ResultsTwenty-four Caucasian male and female volunteers and four assessors showed that the underarms of non-antiperspirant (non-AP) users have significantly higher global sweat odour intensities and harboured on average about 50 times more bacteria than those of AP users. Global sweat odour and odour descriptors sulfury-cat urine and acid-spicy generally increased from the morning to the afternoon sessions. Among non-AP users, male underarm odours were judged higher in intensity with higher fatty and acid-spicy odours and higher bacterial loads. Although the content of odour precursors in underarm secretions varied widely among individuals, males had a higher acid: sulfur precursor ratio than females did. No direct correlations were found between measured precursor concentration and sweat odours. High-throughput sequencing targeting the 16S rRNA genes of underarm bacteria collected from 11 non-AP users (six females and five males) confirmed the strong dominance of the phyla Firmicutes and Actinobacteria, with 96% of sequences assigned to the genera Staphylococcus, Corynebacterium and Propionibacterium. The proportion of several bacterial taxa showed significant variation between males and females. The genera Anaerococcus and Peptoniphilus and the operational taxonomic units (OTUs) from Staphylococcus haemolyticus and the genus Corynebacterium were more represented in males than in females. The genera Corynebacterium and Propionibacterium were correlated and anti-correlated, respectively, with body odours. Within the genus Staphylococcus, different OTUs were either positively or negatively correlated with axillary odour. The relative abundance of five OTUs (three assigned to S. hominis and one each to Corynebacterium tuberculostearicum and Anaerococcus) were positively correlated with at least one underarm olfactory descriptor.ConclusionsPositive and negative correlations between bacterial taxa found at the phylum, genus and OTU levels suggest the existence of mutualism and competition among skin bacteria. Such interactions, and the types and quantities of underarm bacteria, affect the formation of body odours. These findings open the possibility of developing new solutions for odour control.Electronic supplementary materialThe online version of this article (doi:10.1186/s40168-014-0064-3) contains supplementary material, which is available to authorized users.

Antipsychotic Use and Myocardial Infarction in Older Patients With Treated Dementia

Antipsychotic agents (APs) are commonly prescribed to older patients with dementia. Antipsychotic use is associated with an increased risk of ischemic stroke in this population. Our study aimed to investigate the association of AP use with the risk of acute myocardial infarction (MI). A retrospective cohort of community-dwelling older patients who initiated cholinesterase inhibitor treatment was identified between January 1, 2000, and December 31, 2009, using the Quebec, Canada, prescription claims database. From this source cohort, all new AP users during the study period were matched with a random sample of AP nonusers. The risk of MI was evaluated using Cox proportional hazards models, adjusting for age, sex, cardiovascular risk factors, psychotropic drug use, and propensity scores. In addition, a self-controlled case series study using conditional Poisson regression modeling was conducted. Among the source cohort of 37,138 cholinesterase inhibitor users, 10,969 (29.5%) initiated AP treatment. Within 1 year of initiating AP treatment, 1.3% of them had an incident MI. Hazard ratios for the risk of MI after initiation of AP treatment were 2.19 (95% CI, 1.11-4.32) for the first 30 days, 1.62 (95% CI, 0.99-2.65) for the first 60 days, 1.36 (95% CI, 0.89-2.08) for the first 90 days, and 1.15 (95% CI, 0.89-1.47) for the first 365 days. The self-controlled case series study conducted among 804 incident cases of MI among new AP users yielded incidence rate ratios of 1.78 (95% CI, 1.26-2.52) for the 1- to 30-day period, 1.67 (95% CI, 1.09-2.56) for the 31- to 60-day period, and 1.37 (95% CI, 0.82-2.28) for the 61- to 90-day period. Antipsychotic use is associated with a modest and time-limited increase in the risk of MI among community-dwelling older patients treated with cholinesterase inhibitors.

Antipsychotic drugs and risk of pulmonary embolism

Antipsychotic drugs (APs) expose users to several adverse effects. Some reports describe an increased risk of venous thromboembolism for particular drugs in this family. To examine the association between the risks of pulmonary embolism (PE) and AP use and assess any dose-effect relationships. This is a retrospective analysis of data in 'Premier's Perspective' a large US hospital database for 2006. Adults in the AP group had at least one prescription of AP. Logistic regression analysis was performed to detect association between PE and AP use. The dose-effect relationship was assessed according to quantities and administration routes. Analyses were adjusted for potential confounders: age, sex, the components of the Charlson co-morbidity index, diagnoses of infection, sepsis, inflammatory bowel disease, psychotic disorders and hospital inpatient or outpatient status. Among 28,723,771 adults included in 2006, 450,951 (1.6%) were prescribed AP. Haloperidol was most commonly prescribed (157,667 patients or 35.0%), but atypical APs represented over 78% of prescriptions. The risk of PE was higher in AP users than in the total population (OR = 1.17 [95%CI 1.13-1.21]; p < 0.001) and depended on the type of AP used: clozapine was associated with the highest risk. Risk seemed correlated to higher doses. Non-hospital prescription data were unavailable, potentially underestimating the number of patients exposed. The relative timing of AP prescription and PE was not available. Results did not include deep vein thrombosis. This study suggests an increased risk of PE with AP treatment, varying with type of AP and dependent on dose.

Development of APS Films to Give More Benefit to APS Users

Development of APS Films to Give More Benefit to APS Users

Using metallic filters in APS undulator beamlines

Metallic filters are needed by APS users in their beamlines. Two general areas of use for the white-beam metallic filters are: (1) to attenuate the x-ray beam to reduce the thermal load during routine operations and (2) to attenuate the x-ray beam during alignment and for special testing of optics at low power. Metallic filters are important for users who will be working primarily in the high energy x-ray range because unwanted lower energy photons are absorbed through the metallic filters. Notwithstanding their high thermal conductivity, the metals, in general, absorb x-rays significantly near surface layers and hence can attain very large temperatures causing structural deformations and/or damage. Thermomechanical behavior and failure prediction need to be done carefully. In this paper, particulars of metallic filters are discussed and generalized analytical solutions are offered to help users of metallic filters determine their applicability for x-ray beamlines

Argonne National Laboratory high performance network support of APS experiments

Argonne National Laboratory is currently positioned to provide access to high performance regional and national networks. Much of the impetus for this effort is the anticipated needs of the upcoming experimental program at the APS. Some APS collaborative access teams (CATs) are already pressing for network speed improvements and security enhancements. Requirements range from the need for high data rate, secure transmission of experimental data, to the desire to establish a ‘‘virtual experimental environment’’ at their home institution. In the near future, 155 megabit/sec (Mb/s) national and regional asynchronous transfer mode (ATM) networks will be operational and available to APS users. Full-video teleconferencing, virtual presence operation of experiments, and high speed, secure transmission of data are being tested and, in some cases, will be operational. We expect these efforts to enable a substantial improvement in the speed of processing experimental results as well as an increase in convenience to the APS experimentalist.