7,507 research outputs found
Simulation of broaching operations for tool design optimization
In this study, an approach for simulation of broaching operations is presented. The proposed approach calculates the cutting forces, power, maximum stress at the tooth root, chip thickness and rake angle distribution on all teeth, and the workpiece geometry evolution during the process. The developed algorithms are integrated in a computer software that can simulate a whole broaching process to predict various physical parameters and generate some performance measures. The model which is used to optimize the broaching process is briefly presented here together with the industrial applications
Obesity and metabolic syndrome in adolescent survivors of standard risk childhood acute lymphoblastic leukemia in Saudi Arabia
This study estimated prevalence of unhealthy weight status and metabolic syndrome (MS) amongst Saudi survivors of standard risk ALL. Procedure. We recruited 56 survivors, mean age 13.4 years (SD 4.1), a mean of 9.1 years (SD 4.1) postdiagnosis. The BMI for age was used to deďŹne weight status relative to national (Saudi) and international (Cole et al., Cole-IOTF, WHO, and CDC) reference data. We measured body composition by dualenergy X-ray absorptiometry (DXA), waist circumference, blood pressure, lipid proďŹle (HDL-C, Triglycerides), fasting glucose and insulin. Results. According to international deďŹnitions based on BMI for age, around half of the sample had unhealthy weight status. All of the approaches based on BMI for age underestimated overfatness, present in 27/51 (53%) of the sample according to DXA. Prevalence of MS was 7.1% (3/42 of those over 9-years old) and 5.4% (3/56) by applying the International Diabetes Federation (IDF) deďŹnition and National Cholesterol Education Program Third Adult Treatment panel Guidelines (NCEP III), respectively. However, MS by the NCEP III deďŹnition was present in 19% of the overweight and obese survivors and 7.1% of the sample had at least two of the components of MS. Conclusion. Unhealthy body weight and overfatness may be common amongst adolescent Saudi survivors of standard risk ALL, though overweight and obesity may be no more common than in the general Saudi adolescent population. DeďŹning weight status using BMI underestimates overfatness. Ideally, body composition and cardiometabolic risk factors should be monitored at late effects clinics. Pediatr Blood Cancer 2012;59: 133â137. 2011 Wiley Periodicals, Inc
Initiation of Psychotropic Medication after Partner Bereavement: A Matched Cohort Study
Background
Recent changes to diagnostic criteria for depression in DSM-5 remove the bereavement exclusion, allowing earlier diagnosis following bereavement. Evaluation of the potential effect of this change requires an understanding of existing psychotropic medication prescribing by non-specialists after bereavement.
Aims
To describe initiation of psychotropic medication in the first year after partner bereavement.
Methods
In a UK primary care database, we identified 21,122 individuals aged 60 and over with partner bereavement and no psychotropic drug use in the previous year. Prescribing (anxiolytic/hypnotic, antidepressant, antipsychotic) after bereavement was compared to age, sex and practice matched controls.
Results
The risks of receiving a new psychotropic prescription within two and twelve months of bereavement were 9.5% (95% CI 9.1 to 9.9%) and 17.9% (17.3 to 18.4%) respectively; an excess risk of initiation in the first year of 12.4% compared to non-bereaved controls. Anxiolytic/hypnotic and antidepressant initiation rates were highest in the first two months. In this period, the hazard ratio for initiation of anxiolytics/hypnotics was 16.7 (95% CI 14.7 to 18.9) and for antidepressants was 5.6 (4.7 to 6.7) compared to non-bereaved controls. 13.3% of those started on anxiolytics/hypnotics within two months continued to receive this drug class at one year. The marked variation in background family practice prescribing of anxiolytics/hypnotics was the strongest determinant of their initiation in the first two months after bereavement.
Conclusion
Almost one in five older people received a new psychotropic drug prescription in the year after bereavement. The early increase and trend in antidepressant use after bereavement suggests some clinicians did not adhere to the bereavement exclusion, with implications for its recent removal in DSM-5. Family practice variation in use of anxiolytics/hypnotics suggests uncertainty over their role in bereavement with the potential for inappropriate long term use
Municipalities Collaborating in Public Health: The Danish Smoking Prevention and Cessation Partnership
This study explored the Smoking Prevention and Cessation Partnership (SPCP) which builds upon a collaboration between two Danish municipalities targeted at the prevention of tobacco smoking. The aim of the study was to describe the processes of SPCP, to examine the difficulties this collaboration faced, and to assess how these experiences could be used to improve future partnership collaboration. We employed qualitative methodology comprising 12 semi-structured one-to-one interviews with SPCPâs stakeholders and an analysis of the partnership documents and reports. The findings suggested that the main potentials of the partnership were the personal relations between the members and stakeholders with the possibilities of the creation of new connections with other actors. Barriers to successful partnership building were the implementation of the new Local Government Reform as a competing task, and that the two municipalities were heterogenic in respect to organizational issues and working methods. Other impediments included the lack of continuity in leadership, the lack of clarity regarding the form of collaboration and roles, as well as different expectations of the stakeholders. We conclude that four factors remain critical for partnerships. The first is the clarity of the collaborative effort. Second, partnerships need to take into account the structural circumstances and culture/value systems of all stakeholders. Third is the impact of contextual factors on the development of the partnership; and the fourth factor is the bearing of personal/individual factors on the partnership e.g., personal engagement in the project. Early attention to these four factors could contribute to more effective partnership working
Komplexchemie perhalogenierter Cyclopentadiene und Alkine
Pt(PPh3)2(C2H4) reacts with monofluoroacetylene to give the Ď-complex Pt(PPh3)2(FCCH), and with dichloroacetylene under oxidative addition to yield Pt(PPh3)2(Cl)(ClCCl), the structure of which was determined by X-ray crystallography
Timing of elective surgery and risk assessment after SARS-CoV-2 infection: 2023 update
Guidance for the timing of surgery following SARS-CoV-2 infection needed reassessment given widespread vaccination, less virulent variants, contemporary evidence and a need to increase access to safe surgery. We, therefore, updated previous recommendations to assist policymakers, administrative staff, clinicians and, most importantly, patients. Patients who develop symptoms of SARS-CoV-2 infection within 7 weeks of planned surgery, including on the day of surgery, should be screened for SARS-CoV-2. Elective surgery should not usually be undertaken within 2 weeks of diagnosis of SARS-CoV-2 infection. For patients who have recovered from SARS-CoV-2 infection and who are low risk or having low-risk surgery, most elective surgery can proceed 2 weeks following a SARS-CoV-2 positive test. For patients who are not low risk or having anything other than low-risk surgery between 2 and 7 weeks following infection, an individual risk assessment must be performed. This should consider: patient factors (age; comorbid and functional status); infection factors (severity; ongoing symptoms; vaccination); and surgical factors (clinical priority; risk of disease progression; grade of surgery). This assessment should include the use of an objective and validated risk prediction tool and shared decision-making, taking into account the patient's own attitude to risk. In most circumstances, surgery should proceed unless risk assessment indicates that the risk of proceeding exceeds the risk of delay. There is currently no evidence to support delaying surgery beyond 7 weeks for patients who have fully recovered from or have had mild SARS-CoV-2 infection
ELN and FBN2 gene variants as risk factors for two sports-related musculoskeletal injuries
The proteins ELN and FBN2 are important in extracellular matrix function. The ELN rs2071307 and FBN2 rs331079 gene variants have been associated with soft tissue pathologies. We aimed to determine whether these variants were predisposing factors for both Achilles tendinopathy (AT) and anterior cruciate ligament (ACL) ruptures. For the AT study, 135 cases (TEN group) and 239 asymptomatic controls were recruited. For the ACL rupture study our cohort consisted of 141 cases (ACL group) and 219 controls. Samples were genotyped for both the ELN rs2071307 and FBN2 rs331079 variants using TaqMan assays. Analysis of variance and chi-squared tests were used to determine whether either variant was associated with AT or ACL rupture with significance set at p<0.05. The GG genotype of the FBN2 variant was significantly over-represented within the TEN group (p=0.035; OR=1.83; 95% CI 1.04â3.25) compared to the CON group. We also found that the frequency of the G allele was significantly different between the TEN (p=0.017; OR=1.90; 95% CI 1.11â3.27) and ACL groups (p=0.047; OR=1.76; 95% CI 1.00â3.10) compared to controls. The ELN rs207137 variant was not associated with either AT or ACL rupture. In conclusion, DNA sequence variation within the FBN2 gene is associated with both AT and ACL rupture
Programmability of Chemical Reaction Networks
Motivated by the intriguing complexity of biochemical circuitry within individual cells we study Stochastic Chemical Reaction Networks (SCRNs), a formal model that considers a set of chemical reactions acting on a finite number of molecules in a well-stirred solution according to standard chemical kinetics equations. SCRNs have been widely used for describing naturally occurring (bio)chemical systems, and with the advent of synthetic biology they become a promising language for the design of artificial biochemical circuits. Our interest here is the computational power of SCRNs and how they relate to more conventional models of computation. We survey known connections and give new connections between SCRNs and Boolean Logic Circuits, Vector Addition Systems, Petri Nets, Gate Implementability, Primitive Recursive Functions, Register Machines, Fractran, and Turing Machines. A theme to these investigations is the thin line between decidable and undecidable questions about SCRN behavior
Timing of elective surgery and risk assessment after SARS-CoV-2 infection: an update: A multidisciplinary consensus statement on behalf of the Association of Anaesthetists, Centre for Perioperative Care, Federation of Surgical Specialty Associations, Royal College of Anaesthetists, Royal College of Surgeons of England
The impact of vaccination and new SARS-CoV-2 variants on peri-operative outcomes is unclear. We aimed to update previously published consensus recommendations on timing of elective surgery after SARS-CoV-2 infection to assist policymakers, administrative staff, clinicians and patients. The guidance remains that patients should avoid elective surgery within 7 weeks of infection, unless the benefits of doing so exceed the risk of waiting. We recommend individualised multidisciplinary risk assessment for patients requiring elective surgery within 7 weeks of SARS-CoV-2 infection. This should include baseline mortality risk calculation and assessment of risk modifiers (patient factors; SARS-CoV-2 infection; surgical factors). Asymptomatic SARS-CoV-2 infection with previous variants increased peri-operative mortality risk three-fold throughout the 6 weeks after infection, and assumptions that asymptomatic or mildly symptomatic omicron SARS-CoV-2 infection does not add risk are currently unfounded. Patients with persistent symptoms and those with moderate-to-severe COVID-19 may require a longer delay than 7 weeks. Elective surgery should not take place within 10 days of diagnosis of SARS-CoV-2 infection, predominantly because the patient may be infectious, which is a risk to surgical pathways, staff and other patients. We now emphasise that timing of surgery should include the assessment of baseline and increased risk, optimising vaccination and functional status, and shared decision-making. While these recommendations focus on the omicron variant and current evidence, the principles may also be of relevance to future variants. As further data emerge, these recommendations may be revised
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