37 research outputs found

    A simple, efficient, and general treatment of the singularities in Hartree-Fock and exact-exchange Kohn-Sham methods for solids

    Full text link
    We present a general scheme for treating the integrable singular terms within exact exchange (EXX) Kohn-Sham or Hartree-Fock (HF) methods for periodic solids. We show that the singularity corrections for treating these divergencies depend only on the total number and the positions of k-points and on the lattice vectors, in particular the unit cell volume, but not on the particular positions of atoms within the unit cell. The method proposed here to treat the singularities constitutes a stable, simple to implement, and general scheme that can be applied to systems with arbitrary lattice parameters within either the EXX Kohn-Sham or the HF formalism. We apply the singularity correction to a typical symmetric structure, diamond, and to a more general structure, trans-polyacetylene. We consider the effect of the singularity corrections on volume optimisations and k-point convergence. While the singularity corrections clearly depends on the total number of k-points, it exhibits a remarkably small dependence upon the choice of the specific arrangement of the k-points.Comment: 24 pages, 5 Figures, re-submitted to Phys. Rev. B after revision

    Receiving a diagnosis of young onset dementia: a scoping review of lived experiences

    Get PDF
    Objectives: Personal experiences of receiving a diagnosis of young onset dementia (YOD) are often overlooked in a complex assessment process requiring substantial investigation. A thematic synthesis of published until November 2018 qualitative studies was completed to understand the lived experiences of younger people. This informed a Delphi study to learn how diagnostic processes could be improved, identify the strengths and weaknesses of current approaches, and help educate professionals concerning key issues. Method: Systematic searches of bibliographic databases were conducted involving self-reported experiences of diagnosis of YOD. Eight out of 47 papers identified were quality assessed using Walsh & Browne's criteria for methodological appraisal. Results: The review emphasises that delays in diagnosis can often be attributed to (1) delays in accessing help, and (2) misattribution of symptoms by the clinician. The impact of diagnosis is influenced by the clinician's use of language; and reactions to diagnosis varied from feelings of reassurance (in that their symptoms are now explained), to shock and destabilisation. Conclusion: This review suggests that improving the recognition of presenting symptoms, reducing diagnostic errors, and identifying the emotional needs arising from diagnosis are required to improve the diagnostic experience for younger adults, and to promote future engagement with services

    Armodafinil versus Modafinil in Patients of Excessive Sleepiness Associated with Shift Work Sleep Disorder: A Randomized Double Blind Multicentric Clinical Trial

    Get PDF
    Aim. To compare the efficacy and safety of armodafinil, the R-enantiomer of modafinil, with modafinil in patients of shift work sleep disorder (SWSD). Material and Methods. This was a 12-week, randomized, comparative, double-blind, multicentric, parallel-group study in 211 patients of SWSD, receiving armodafinil (150 mg) or modafinil (200 mg) one hour prior to the night shift. Outcome Measures. Efficacy was assessed by change in stanford sleepiness score (SSS) by at least 2 grades (responder) and global assessment for efficacy. Safety was assessed by incidence of adverse events, change in laboratory parameters, ECG, and global assessment of tolerability. Results. Both modafinil and armodafinil significantly improved sleepiness mean grades as compared to baseline (P < .0001). Responder rates with armodafinil (72.12%) and modafinil (74.29%) were comparable (P = .76). Adverse event incidences were comparable. Conclusion. Armodafinil was found to be safe and effective in the treatment of SWSD in Indian patients. The study did not demonstrate any difference in efficacy and safety of armodafinil 150 mg and modafinil 200 mg

    Prescription of medicines by medical students of Karachi, Pakistan: A cross-sectional study

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Prescription of medicines by non-doctors is an issue with serious global implications. To our knowledge prescription of drugs by medical and non-medical students has not been studied before. We aimed to determine the practice and attitudes of drug prescription by medical students and: a) how non-medical students respond to this practice, b) How this compares with the attitudes and practices of non-medical students.</p> <p>Methods</p> <p>A cross-sectional study was conducted on a sample of 600 students randomly selected from 2 medical and 2 non-medical universities. Ethical requirements were ensured and data was collected using self administered questionnaires. The Chi square tests and logistic univariate regression analyses were performed using SPSS v 14 to identify associations and differences.</p> <p>Results</p> <p>A total of 572 forms were completed and the sample consisted of 295 medical students and 277 non-medical students with no significant difference in their demographic profile. Of the 295 medical students 163 (55.3%) had prescribed a medicine independently and most (48.5%) said that they did this 2–3 times a year. The commonest reasons for this were 'previous experience' (68.7%), 'problem too trivial' (34.4%) and 'we knew everything about the condition' (31.3%). One-third (33.6%) of the undergraduate medical students thought that it was alright to independently diagnose an illness while a vast majority (78.3%) thought that it was alright for them to prescribe medicines to others. Common prescriptions were pain-killers, antipyretics, antiallergics and antibiotics. Medical students who prescribed medicines were of lesser age (CI = 1.366–1.887) and more likely to belong to the 1<sup>st </sup>(CI = 3.588–21.731), 2<sup>nd </sup>(CI = 2.059– 10.869) or 3<sup>rd </sup>(CI = 4.331–26.374) year of medical college. One-third (33.9%) of the non-medical students reported that a medical student had prescribed medicines to them and 21.3% said that they trusted medical students and would follow their advice blindly. Many students thought it alright for medical students to diagnose and treat illnesses. A similar proportion of non-medical students (58.5%) reported prescribing medicines to others.</p> <p>Conclusion</p> <p>Prescription of medicines by non-doctors is rampant and urgent corrective measures are warranted. We have highlighted areas for future research and intervention and have given a few recommendations.</p

    Drug-prescribing patterns during pregnancy in the tertiary care hospitals of Pakistan: a cross sectional study

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The rationale for use of drugs during pregnancy requires a careful assessment as in addition to the mother, the health and life of her unborn child is also at stake. Information on the use of drugs during pregnancy is not available in Pakistan. The aim of this study was to evaluate the patterns of drug prescriptions to pregnant women in tertiary care hospitals of Pakistan.</p> <p>Methods</p> <p>This was a cross-sectional study conducted at five tertiary care hospitals of Pakistan. Copies of outpatient medicinal prescriptions given to pregnant patients attending the antenatal clinics were collected. The drugs were classified according to the pharmacological class and their teratogenic potential.</p> <p>Results</p> <p>All the pregnant women attending the antenatal clinics received a prescription containing at least one drug. A total of 3769 distinct prescriptions given to different women were collected. Majority of the women who received the prescriptions belonged to third trimester (55.4%) followed by second (33.6%) and first trimester (11.0%). On an average, each prescription contained 1.66 ± 0.14 drugs. The obstetricians at Civil Hospital, Karachi and Chandka Medical College Hospital, Larkana showed a tendency of prescribing lesser number of drugs compared to those in other hospitals. Anti-anemic drugs including iron preparations and vitamin and mineral supplements (79.4%) were the most frequently prescribed drugs followed by analgesics (6.2%) and anti-bacterials (2.2%). 739 women (19.6%) received prescriptions containing drugs other than vitamin or mineral supplements. Only 1275 (21.6%) of all the prescribed drugs (n = 6100) were outside this vitamin/mineral supplement class. Out of these 1275 drugs, 29 (2.3%) drugs were prescribed which are considered to be teratogenic. Misoprostol was the most frequently prescribed (n = 6) among the teratogenic drugs followed by carbimazole (n = 5) and methotrexate (n = 5). Twenty nine pregnant women (0.8% of all the women studied) were prescribed these teratogenic drugs.</p> <p>Conclusion</p> <p>Less than one percent of the pregnant women attending tertiary care hospitals in Pakistan are prescribed teratogenic drugs. The prescribing practices of Pakistani physicians are similar to those in western countries.</p

    Spatial and temporal variations in indoor air quality in Lahore, Pakistan

    Get PDF
    Indoor air pollution is a significant economic burden in Pakistan with an annual cost of 1% of gross domestic product. Moreover, according to the World Health Organization 81% of the population use solid fuels with 70,700 deaths annually attributable to its use. Despite this situation, indoor air pollution remains to be recognized as a hazard at policy level in Pakistan and there are no standards set for permissible levels of indoor pollutants. The current study was designed to monitor the indoor air quality in residential houses (n = 30) in Lahore, Pakistan. PM2.5 and bioaerosols were monitored simultaneously in the kitchens and living rooms. Activity diaries were kept during the measurement periods. It was observed that cooking, cleaning and smoking were the principal indoor sources while infiltration from outdoors, particularly in the semi-urban and industrial areas, also made significant contributions. Maximum and minimum air change rate per hour was determined for each microenvironment to observe the influence of ventilation on indoor air quality. Lahore has a low-latitude semi-arid hot climate, and a significant impact of season was observed upon bacterial and fungal levels. It was also observed that the PM2.5 levels rose during the colder months and decreased significantly during the summer season. Low ventilation rates during the winter season as well as meteorological factors resulted in elevated PM levels

    Effects of increased paternal age on sperm quality, reproductive outcome and associated epigenetic risks to offspring

    Get PDF

    Prediction of pre-eclampsia during early pregnancy in primiparas with soluble fms-like tyrosine kinase-1 and placental growth factor

    No full text
    Background: We hypothesized that pre-eclampsia (PE) can be predicted early in primiparas by measuring serum levels of soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PIGF). Methods: All normotensive primiparas attending the antenatal clinics of Aga Khan University Hospital and Aga Khan Hospital for Women, Karachi, Pakistan without any known risk factor for PE were invited to participate in the study. They were divided into two groups based on the development of PE. Their blood samples were collected at 8-15, 16-22, 23-28, 29-34 weeks of pregnancy and once within 1 week of delivery. All samples were analysed for sFlt-1 and PIGF. Results: Six hundred and eleven (46.7%) of 1307 recruited primiparas completed the study according to the protocol. Of these, 39 (6.4%) women developed PE. The difference in serum sFlt-1 was evident as early as 15 weeks of gestation. Higher levels of serum sFlt-1 were present in women who later developed PE. Relatively higher levels of PIGF were observed in non-PE women compared to PE women up to 22 weeks of gestation. However, after 23 weeks of pregnancy, PIGF levels increased in both the groups, but less so in the PE group. Receiver operator characteristics (ROC) curve analysis showed that even in early pregnancy (gestation), serum sFlt-1 alone has the potential to predict PE with area under the curve (AUC), sensitivity and specificity of 0.81, 75.9 and 72.4, respectively. Conclusion: PE can be predicted in primiparas in the early part of second trimester with serum levels of sFlt-1 and in the later part of second trimester with serum levels of PIGF
    corecore