Accelerating atomic structure search with cluster regularization.

We present a method for accelerating the global structure optimization of atomic compounds. The method is demonstrated to speed up the finding of the anatase TiO2(001)-(1 × 4) surface reconstruction within a density functional tight-binding theory framework using an evolutionary algorithm. As a key element of the method, we use unsupervised machine learning techniques to categorize atoms present in a diverse set of partially disordered surface structures into clusters of atoms having similar local atomic environments. Analysis of more than 1000 different structures shows that the total energy of the structures correlates with the summed distances of the atomic environments to their respective cluster centers in feature space, where the sum runs over all atoms in each structure. Our method is formulated as a gradient based minimization of this summed cluster distance for a given structure and alternates with a standard gradient based energy minimization. While the latter minimization ensures local relaxation within a given energy basin, the former enables escapes from meta-stable basins and hence increases the overall performance of the global optimization.

Comparison of two different anaerobic feeding strategies to establish a stable aerobic granulated sludge bed.

Two different anaerobic feeding strategies were compared to optimize the development and performance of aerobic granules. A stable aerobic granulation of activated sludge was achieved with an anaerobic plug flow operation (PI) and a fast influent step followed by an anaerobic mixing phase (PII). Two lab scale sequencing batch reactors (SBRs) were operated to test the different operation modes. PI with plug flow and a reactor H/D (height/diameter) ratio of 9 achieved a biomass concentration of 20 g(TSS)/L and an effluent TSS concentration of 0.10 g(TSS)/L. PII with the mixed anaerobic phase directly after feeding and a reactor H/D ratio of 2 achieved a biomass concentration of 9 g(TSS)/L and an effluent quality of 0.05 g(TSS)/L. Furthermore, it is shown that the plug flow regime during anaerobic feeding together with the lower H/D ratio of 2 led to channeling effects, which resulted in lower storage of organic carbon and a general destabilization of the granulation process. Compared to the plug flow regime (PI), the anaerobic mixing (PII) provided lower substrate gradients within the biofilm. However, these disadvantages could be compensated by higher mass transfer coefficients in PII (k(L) = 0.3 m/d for PI; k(L) = 86 m/d for PII) during the anaerobic phase.

[Long-term results after Charnley hip replacement]. / Langtidsresultater efter total hoftealloplastik ad modum Charnley.

We made a prospective study of 241 Charnley total hip replacements performed between 1968 and 1974. In 1990 we reviewed 92 patients with 103 hips or 96% of surviving hips at a mean follow-up of 17.6 years (15 to 20.6). The clinical results were excellent with Charnley scores of four or more for pain in 95% of the cases, for function in 73% and for movement in 93%. Of the whole series, 8.3% had been revised and Kaplan Meier survival analysis showed a probability of revision at 20 years of 10.7%. No significant difference concerning the results was found between young patients operated between the ages of 34 to 55, and older patients operated between the ages of 56 to 79 years. These results are similar to those from the few other series with extended follow-up and make it difficult to justify the present widespread use of uncemented hip prostheses.

Total hip arthroplasty with the Charnley prosthesis in patients fifty-five years old and less. Fifteen to twenty-one-year results.

Data on 240 primary Charnley total hip arthroplasties, performed in 211 patients from October 1968 to July 1974, were recorded prospectively. Fifty-two prostheses were implanted in forty-six patients who were thirty-four to fifty-five years old, and 188 prostheses were implanted in 165 patients who were more than fifty-five years old. The results for the younger patients were compared with those for the older patients. Twenty hips were revised over-all, and all five of the infections and four of the five fractures of the femoral stem that occurred in this group were in the older patients. However, the rate of aseptic loosening was similar for the two age-groups (three of the hips in the younger patients and five in the older patients). The probability of revision after twenty years for the two groups, as determined with Kaplan-Meier analysis, was 11.7 per cent for the younger patients and 10.7 per cent for the older patients. There was no significant difference between the two groups with regard to either the number of revisions or the percentage of patients who had radiographic signs of loosening. The median Charnley hip scores during the course of the study were also similar for the two groups. We recommend that Charnley low-friction arthroplasty be used even in younger patients, as the long-term results were excellent and were comparable with those in the elderly age-group.

A model of regular geriatric follow-up by home visits to selected patients discharged from a geriatric ward: a randomized controlled trial.

The aim of this randomized controlled trial was to describe and evaluate a model of regular follow-up by home visits to selected elderly patients discharged from a geriatric ward. Ninety-seven patients were randomized to receive regular follow-up visits by a geriatric team at 1, 3, 8 and 16 weeks after discharge, and 96 patients to receive standard care. Based on the geriatric evaluation, medical and social adjustment was carried out, if indicated. Six months after discharge, significantly more patients in the intervention group were allocated to home help (p < 0.05), but only 42 (44%) were readmitted to a hospital, vs 62 (64%) in the control group (p < 0.005). Differences between the groups in mortality and nursing-home placement were not statistically significant. Regular follow-up home visits by a geriatric team after in-patient geriatric evaluation and management reduce the risk of hospital readmissions among highly selected frail geriatric patients.

[Current cooperation concerning admission to and discharge from geriatric hospitals]. / Nyt samarbejde om gamle menneskers sygehusindlaeggelse og -udskrivelse.

A method of building bridges--in terms of therapy and care--between the life of the elderly before, during, and after a stay in hospital is described in this randomized, controlled study from a Copenhagen suburb. A project nurse employed by the City called at the Hospital each day and followed the members of this group concerning the need to gather information from primary care, discuss discharge with the patient and the nursing staff, co-ordinate possible supportive measures in the home, and immediately after the discharge to make a home visit to ensure continuity of care and treatment.

[Cooperation concerning admission to and discharge of elderly people from the hospital. 1. The coordinated contributions of home care personnel]. / Samarbejde om gamle menneskers sygehusindlaeggelse og -udskrivelse. 1. Hjemmesygeplejerskens koordinerende indsats på sygehuset.

In cooperation between the home care system in the Municipality of Rødovre and four hospital departments in the County of Copenhagen, a controlled and randomized investigation was undertaken among the hospitalized patients of 65 years and over from the Municipality of Rødovre. A nurse employed by the Municipality particularly for this project visited the hospital daily and followed the 135 participants in the intervention group with the objects of obtaining information from the primary sector if necessary, discussing discharge with the patient and the hospital staff, coordinating possible supportive measures in the patient's home and visiting the patient in his home immediately after discharge from hospital in order to ensure continuity in care and treatment. The 138 participants in the control group underwent the usual procedures in connection with admission to hospital. In this article, the consequences of the contributions by the health visitor in the hospital are described in relation to the course of hospitalization. The intervention group had an average stay in hospital of 11.0 days as compared with 14.3 days in the control group (p greater than 0.05), and the total number of bed-days were 1,490 and 1,970, respectively. In addition, the two groups were compared as regards the number of diagnostic procedures during hospitalization, the number of deaths, the diagnoses on discharge and the functional capacity. No differences were observed in these respects between the two groups. Three patients from the control group were discharged to residential institutions as compared with none in the intervention group.(ABSTRACT TRUNCATED AT 250 WORDS)

State of health and its association with death among old people at three-years follow-up. II. Consumption of medicine subjective and objective general health.

Five hundred eighty-five inhabitants of Copenhagen, aged 75, 80, and 85 years, were visited in their homes and asked about consumption of medicine and subjective health; in addition, a general medical examination was carried out by a physician. Taking biological aging into consideration, 34.8% of the participants were found to be of normal health. The 75 year-old men differed from the other age groups and the women by having a better subjective and objective health. A total of 74.5% of the participants claimed to be in good health. After three years and again after five years, mortality was found to be most strongly related to the number of admissions to hospital and institutionalisation. Poor subjective health was more strongly related to mortality than poor objective health, particularly after five years. Of the participants, 74.2% consumed medicine regularly. The largest intake of drugs was found among women, the oldest participants, those living in institutions, and those living alone.

State of health and its association with death among old people at three-years follow-up. I. Lung function, circulation, sensory and motor apparatus.

A general medical examination was performed of 569 Copenhagen inhabitants aged 75, 80, and 85 years in the participants' own homes as part of an epidemiological, sociomedical intervention study. The present report contains the results of this examination regarding lung function, circulation, sensory, and motor apparatus. Curves are presented expressing the normal peak expiratory flow rate (PEFR) for men and women 75-85 years old. More men than women had a compromised lung function. Regarding circulation and motor apparatus, more women and 85-year-olds showed impairments. Functional vision and hearing declined with age, but no significant differences could be demonstrated between men and women, although a preponderance of women tended to show hearing disability. Institutionalised participants were more inclined to have impairment of lung function and sight and to walk with difficult. Gait disturbances and impairment of vision were the objective health measurements most strongly related to death at follow-up after three years.

Follow-up three years after intervention to relieve unmet medical and social needs of old people.

A follow-up study was conducted 3 years after a socio-medical intervention had been performed as part of an epidemiological study of 75-, 80- and 85-year-old citizens of Copenhagen. The intervention was aimed at relieving unmet medical and social needs of this group of citizens. The main recipients of social services were the oldest, single persons and women. A preponderance of the oldest had unmet social needs, but the need for health intervention did not vary according to age or sex. Although a fifth of the participants displayed unmet health needs and a third unmet social needs, no difference could be demonstrated at follow-up between participants and controls with regard to mortality, hospitalization, and institutionalization. Nor could any difference be found regarding subjective health and economy, loneliness, quality of life and functional ability. This is in contrast to the findings of another recent Danish intervention study. On the basis of the present study and other Scandinavian intervention studies, the authors conclude that in countries with a well-developed social system, efforts to improve the living conditions of the elderly should be concentrated to those who are at particular risk. Also for ethical reasons individualized intervention is greatly preferable to general intervention. It is conceivable, however, that not all risk factors, perhaps not even the most important, can be eliminated by intervention.

Increased total mortality and decreased functional capacity are associated with low systolic blood pressure among elderly women.

As part of an epidemiological survey of 75-, 80- and 85-year-old citizens of Copenhagen, the blood pressure of 566 participants was measured at home visits. Based on WHO criteria, systolic hypertension was present in 66% of the men and 71% of the women, and diastolic hypertension was demonstrated in 18% of the men and 22% of the women. The systolic blood pressure was significantly higher among women than among men. Surprisingly, the mortality rate was highest among women with low systolic blood pressure. There was no correlation between blood pressure and morbidity, except among men with low systolic blood pressure, the majority of whom suffered from neoplasms. The women with the lowest systolic blood pressure displayed poor functional capacity in four--and the men in one--out of ten partial functions. No correlation could be demonstrated between blood pressure and intake of medicine. In fact, participants receiving antihypertensives had higher systolic and diastolic blood pressures compared with the other participants.

Quality of life in old age. A population study of elderly in Copenhagen.

733 elderly citizens of Copenhagen filled in a questionnaire about quality of life. This questionnaire formed part of a follow-up performed 3 years after a socio-medical intervention study. A modified Cantril ladder scale was used to evaluate quality of life. When asked about the best and the worst that could happen, nearly half of the old people mentioned health. The second and third subjects most often mentioned were dwelling conditions and contact with relatives. There was no correlation between scores on the ladder scale and sex and age. The socio-medical intervention performed 3 years previously had no measurable effect on quality of life. Old people with a low score on the ladder scale were more inclined to be housebound, feel lonely, stay in institutions, and have a poor subjective health and economy compared with respondents with a high score.

Subchondral pO2, pCO2, pressure, pH, and lactate in human osteoarthritis of the hip.

The pathogenesis of primary human osteoarthritis is unknown. It has been suggested that hypoxia caused by reduced subchondral blood flow plays a central role in the development of tissue damages in osteoarthritis. This hypothesis was investigated using an in situ technique based on mass spectrometry to measure subchondral pO2 and pCO2 in both femoral heads of patients with late stage unilateral osteoarthritis and the normal opposite hip. Intraosseous pressure was recorded and lactate concentrations and pH were measured in blood samples obtained from the two femoral heads. The subchondral pO2 in the diseased hip was significantly lower than pO2 in the normal hip (43 torr versus 63 torr). The intraosseous pressure was significantly higher in the diseased than in the normal hip. The lactate concentration showed a 50% increase in the diseased hip. There were no differences in pCO2 and pH between the two locations.

Intraosseous pressures of oxygen and carbon dioxide in coxarthrosis.

We have investigated the intraosseous partial pressures in 15 patients suffering from primary arthrosis of the hip. The measurements were performed by a mass spectrometer via a specially designed inlet system. The average pO2 and pCO2 values in the femoral head were 8.2 and 6.8 kPa (62 and 52 mmHg), respectively, and in the greater trochanter 6.6 and 5.1 kPa (51 and 39 mmHg). The average intraosseous pressures in the femoral head and greater trochanter were 5.5 and 3.0 kPa (42 and 23 mmHg). The differences between the intraosseous pressures, pO2 and pCO2 in the greater trochanter and the femoral head were all significant.