Investigation of protein folding by mass spectrometry

Bone repair by regeneration as we know it continues to undergo changes, with advances approaching that may change our treatment of patients with craniofacial deformities and skeletal defects. Perhaps by the turn of the century, patients born with asymmetric deformities due to lack of growth will be treated early in life by skeletal stretching, and then later in life by skeletal distraction that is followed by use of accelerating factors to assist the healing processes. All of these available modalities are part of the regeneration of new bone formation. The future of such changes is very interesting, and our ability to help our patients will be maximized. We may even look back 25 years from now at bone grafting and find it to be obsolete and crude. It is hoped that with the new modalities being developed, we will not deviate from the use of a bone grafting procedure, which is the workhorse of the craniofacial surgeon. Bone grafting is used by all surgeons working on the craniofacial skeleton despite the problems of unpredictability of healing and an inability to calculate what percentage of the original graft will survive. The transplantation issue will be solved. The problems with donor site morbidity will continue. The use of inorganic bone substitutes will continue to have its limitation, particularly in type II wounds, which we as plastic surgeons see in the craniofacial region. As we redefine our approach to skeletal repair, we may look back and find solutions to some of the major problems we have had. The rapid stretch of soft tissue after facial advancement or structural alteration that is accompanied by a relapse due to the elastic recoil of the soft tissue could be eliminated by gradual distraction. The bone will undergo better functional adaptation when it has a gradual change in structure based on adjustment and molding in a gradual fashion. The problem of donor site morbidity and a prediction formula for bone could be resolved with new bone formation in situ by mineralization of the area under repair. Bone healing enhancers are here to stay and their clinical application will produce a far-reaching better final outcome (Fig. 11).     

Tailored written invitations for second round breast cancer screening: a randomised controlled trial

OBJECTIVES: Firstly, to determine if attendance for second round mammography screening in those sent a tailored letter (that is, making reference to their screening history) is increased compared with those sent a standard letter; secondly, to investigate the acceptability of tailored letters. SETTING: North West Glasgow Breast Screening Centre. METHODS: A randomised controlled trial. RESULTS: Overall attendance was unrelated to whether the women were sent a tailored or standard letter; 60% of those sent the standard letter attended (922/1531) compared with 62% of those sent the tailored letter (956/1552) (chi 2 = 0.61, P = 0.4) (difference 2%; 95% confidence interval -2% to 5%). There were no significant differences in percentage attendance within each of the study subgroups: women who attended previously and received an all clear result, women who attended previously and received a false positive result, women who were invited previously and failed to attend, and women who were previously too young to be invited for screening. However, there was a statistically significant difference in percentage attendance between these four groups, independent of letter type (chi 2 = 510, P < 0.00001). Although women found the letters acceptable and understandable, they did not seem to pay close attention to the content. CONCLUSIONS: Tailoring invitation letters does not have a significant effect on uptake rates for breast screening and does not justify the additional workload required.     

Processing options for CdTe thin film solar cells

Processing options for addressing critical issues associated with the fabrication of thin film CdTe solar cells are presented, including window and buffer layer processing, post-deposition treatment, and formation of stable low resistance contacts. The paper contains fundamental data, engineering relationships and device results. Chemical surface deposited CdS and Cd_1−xZn_xS films are employed as the n-type heteropartner window layers. Maintaining junction quality with ultra-thin window layers is facilitated by use of a high resistance oxide buffer layer, such as SnO₂, In₂O₃ or Ga₂O₃, between the heteropartner and the transparent conductive oxide. Thermal annealing of the CdTe/CdS heterostructure in the presence of CdCl₂ and O₂ shifts the chemical equilibrium on the surface of the absorber layer, which influences the bulk electrical properties. Aspects of back contacting CdTe/CdS devices, including etching, Cu application, contact annealing, back contact chemistry and secondary contacts, are discussed. Two commonly employed etches used to produce a Te-rich layer, nitric acid/phosphoric acid mixtures and Br₂/methanol are compared, including the nature and stability of the final treated CdTe surface. The diagnostic abilities of the surface sensitive VASE and GIXRD techniques are highlighted. Various methods of Cu delivery are discussed with consideration to; reaction with Te, processing simplicity, processing time and possible industrial scale-up. Some aspects of back contact stability are presented, including discussion of apparent robust back contacts, which contain a thick Te component.     

On transitive orientations with restricted covering graphs

We consider the problem of finding a transitive orientation of a comparability graph, such that the edge set of its covering graph contains a given subset of edges. We propose a solution which employs the classical technique of modular tree decomposition. The method leads to a polynomial time algorithm to construct such an orientation or report that it does not exist.     

TEM investigations of biogenic magnetite extracted from the human hippocampus

Modification of chemical and magnetic extraction techniques has yielded biogenic magnetite/maghemite from human hippocampal tissue. Particles were identified using high resolution transmission electron microscopy, electron diffraction and elemental analysis. Though its presence has been inferred from magnetic analyses, this is the first direct observation of magnetic biominerals from the hippocampus.     

Rheology and filling characteristics of particulate dispersions in polymer melt formulations for liquid fill hard gelatin capsules

OBJECTIVE: In the postmenopausal years, women develop a central pattern of fat distribution and an increased risk of developing cardiovascular disease (CVD). The possibility that these events are related has not been extensively investigated. The object of the present study was to test the hypotheses that, 1) menopause-related differences in lipids are associated with greater estimated intra-abdominal adiposity, and 2) the relationship between individual adipose depots and plasma lipids differs with menopausal status. DESIGN: Cross-sectional. SUBJECTS: 141 healthy pre- and postmenopausal women aged 35-65 y. MEASUREMENTS: Total body fat by hydrodensitometry was used as an index of whole-body adiposity, the sum of five central skinfold measurements as an index of subcutaneous upper-body adiposity, and estimated intra-abdominal adipose tissue (IAF) as an index of visceral adiposity. Fasting plasma concentrations of total cholesterol (total-C), high- and low-density-lipoprotein cholesterol (HDL-C, LDL-C), and triglycerides were used as indices of CVD risk. RESULTS: Postmenopausal women had greater total body fat (P < 0.001), summed central skinfolds (P < 0.01), estimated IAF (P < 0.001), higher plasma concentrations of total-C (P < 0.001), LDL-C (P < 0.001) and triglycerides (P < 0.001), than premenopausal women. The relationship between central skinfolds and LDL-C differed with menopausal status, being significant in pre- but not postmenopausal women. Adjustment for estimated IAF with analysis of covariance decreased menopause-related differences in levels of total-C, LDL-C and triglycerides by approx 40-70%. CONCLUSION: These observations suggest that, 1) menopause-related changes in IAF may adversely affect the plasma lipid profile, and 2) menopausal status affects the relationship between central subcutaneous fat and LDL-C. Studies with measured IAF are needed to confirm present results.     

Population versus clinical view of case fatality from acute coronary heart disease: results from the WHO MONICA Project 1985-1990. Multinational MONItoring of Trends and Determinants in CArdiovascular Disease

BACKGROUND: The clinical view of case fatality (CF) from acute myocardial infarction (AMI) in those reaching the hospital alive is different from the population view. Registration of both hospitalized AMI cases and out-of-hospital coronary heart disease (CHD) deaths in the WHO MONICA Project allows both views to be reconciled. The WHO MONICA Project provides the largest data set worldwide to explore the relationship between CHD CF and age, sex, coronary event rate, and first versus recurrent event. METHODS AND RESULTS: All 79,669 events of definite AMI or possible coronary death, occurring from 1985 to 90 among 5,725,762 people, 35 to 64 years of age, in 29 MONICA populations are the basis for CF calculations. Age-adjusted CF (percentage of CHD events that were fatal) was calculated across populations, stratified for different time periods, and related to age, sex, and CHD event rate. Median 28-day population CF was 49% (range, 35% to 60%) in men and 51% (range, 34% to 70%) in women and was particularly higher in women than men in populations in which CHD event rates were low. Median 28-day CF for hospitalized events was much lower: in men 22% (range, 15% to 36%) and in women 27% (range, 19% to 46%). Among hospitalized events CF was twice as high for recurrent as for first events. CONCLUSIONS: Overall 28-day CF is halved for hospitalized events compared with all events and again nearly halved for hospitalized 24-hour survivors. Because approximately two thirds of 28-day CHD deaths in men and women occurred before reaching the hospital, opportunities for reducing CF through improved care in the acute event are limited. Major emphasis should be on primary and secondary prevention.