Enhanced Thermal Stability of Planar Perovskite Solar Cells Through Triphenylphosphine Interface Passivation.

While extensive research has driven the rapid efficiency trajectory noted to date for organic-inorganic perovskite solar cells (PSCs), their thermal stability remains one of the key issues hindering their commercialization. Herein, a significant reduction in surface defects (a precursor to perovskite instability) could be attained by introducing triphenylphosphine (TPP), an effective Lewis base passivator, to the vulnerable perovskite/spiro-OMeTAD interface. Not only did TPP passivation enable a high power conversion efficiency (PCE) of 20.22 % to be achieved, these devices also exhibited superior ambient and thermal stability. Unlike the pristine device, which exhibited a sharp descend to 16 % of its initial PCE on storing in relative humidity of 10 %, at 85 °C for more than 720 h, the TPP-passivated devices retained 71 % of its initial PCE. Hence, this study presents a facile yet excellent approach to attain high-performing yet thermally stable PSCs.

Congenital myasthenic syndrome due to homozygous CHRNE mutations: report of patients in Arabia.

We describe the clinical characteristics of 3 siblings from 1 family with congenital myasthenic syndrome due to homozygous mutations of the gene coding for the epsilon subunit of the acetylcholine receptor (CHRNE). Onset of symptoms occurred in the first few months of life with ptosis, restricted ocular motility, mild proximal weakness, and difficulty swallowing. Multiple hospital admissions were required due to recurrent pulmonary infections. There was no decremental conduction on repetitive nerve stimulation, but jitter was increased on single fiber electromyographic. Since early childhood, our patients have done well without pulmonary or bulbar symptoms and with partial improvement on pyridostigmine therapy. Response of ptosis to diagnostic ice pack test was striking. Although these siblings have a clinical history and examination findings typical of homozygous CHRNE mutations, the clinical presentation of congenital myasthenia subtypes is variable, and accurate genotyping is essential in choosing the appropriate treatment.

Can medical education rise to the challenge of the African crisis?

In the face of the worsening health crisis in Africa, educationalists there and beyond are challenged to identify their role in resolving the crisis. The training of doctors has to be re-orientated so that they are well equipped to lead the way towards improving the health situation and effectively participating in improving the general condition of the people. This can be achieved by medical schools having control of their duties and functions and using these powers to train doctors who are community-orientated, able to identify clinical and epidemiological problems and find suitable solutions. Doctors of the future should be comfortable working in the community with other members of health teams and confident in addressing all health-related matters in the community. During their formative years in medical school they should acquire the skills to continue self education.This paper discusses some of the important steps that should be taken by medical schools, taking into account the present situation in Africa

No evidence for short or long term morbidity after increased titer measles vaccination in Sudan.

BACKGROUND: Increased mortality rates have been reported after high titer measles [>10(5.0) plaque-forming units (PFU)] vaccination in several large studies in the developing world. An increased titer measles vaccine study conducted in Sudan included a prolonged prospective evaluation of childhood morbidity after vaccination. METHODS: Five hundred ten children (170 per group) were randomized to receive 1 of 3 regimens at 5 and 9 months of age: (1) meningococcal vaccine, then standard titer (50% tissue culture-infective dose, 103.8) Schwarz measles vaccine; (2) increased titer (10(4.7) PFU) Edmonston-Zagreb measles vaccine followed by meningococcal vaccine; and (3) increased titer (10(4.7) PFU) Connaught vaccine followed by standard titer Schwarz measles vaccine. RESULTS: Health workers collected information at 31,582 semi-monthly and monthly visits during 5 years. No increase in infant mortality was observed, but the statistical power was limited. There were 13, 13 and 10 deaths in the Schwarz, Edmonston-Zagreb and Connaught groups, respectively. There were no differences in duration or incidence of illness between groups at any time during the 5-year follow-up, with comparisons stratified by age and sex. Statistical power for each pairwise comparison was good, with at least 80% power to detect a difference of 1 day per month of illness and a 12% difference in the proportion of visits with an illness recorded. CONCLUSIONS: We were unable to document increased morbidity in recipients of the increased titer measles vaccines used in this study. These data do not support the hypothesis that increased mortality after increased titer vaccine exposure is the result of increased and cumulative morbidity.

Evaluation of continuing medical education in Al-qasim, saudi arabia.

OBJECTIVE: To evaluate CME activities in Al-Qassim region in the Kingdom of Saudi Arabia METHODS: A study using a pre-structured questionnaire was conducted in Al-Qassim, targeting physicians working in the hospitals. The survey was conducted in two phases. The first phase was conducted at the inception of the department of professional education and the second one year later. Questionnaires were given to a sample of physicians working in the hospitals. RESULTS: Mean CME hours in the region increased from 5.5(±5.9) to 14.2(±19.7), p=0.0001. 50% said that the CME should be presented differently. There was a need for regular courses (61%), departmental and bedside activities (52%) and visiting speakers (45%). Only 47% of the physicians were using the Internet. CONCLUSION: There is a need to shift from credit counting to a process that can yield professional development through practical courses and departmental activities. The use of the Internet in CME activities should be encouraged.