Lithium-doping inverts the nanoscale electric field at the grain boundaries in Cu2ZnSn(S,Se)4 and increases photovoltaic efficiency.

Passive grain boundaries (GBs) are essential for polycrystalline solar cells to reach high efficiency. However, the GBs in Cu2ZnSn(S,Se)4 have less favorable defect chemistry compared to CuInGaSe2. Here, using scanning probe microscopy we show that lithium doping of Cu2ZnSn(S,Se)4 changes the polarity of the electric field at the GB such that minority carrier electrons are repelled from the GB. Solar cells with lithium-doping show improved performance and yield a new efficiency record of 11.8% for hydrazine-free solution-processed Cu2ZnSn(S,Se)4. We propose that lithium competes for copper vacancies (forming benign isoelectronic LiCu defects) decreasing the concentration of ZnCu donors and competes for zinc vacancies (forming a LiZn acceptor that is likely shallower than CuZn). Both phenomena may explain the order of magnitude increase in conductivity. Further, the effects of lithium doping reported here establish that extrinsic species are able to alter the nanoscale electric fields near the GBs in Cu2ZnSn(S,Se)4. This will be essential for this low-cost Earth abundant element semiconductor to achieve efficiencies that compete with CuInGaSe2 and CdTe.

Morphological and chemical influences on alumina-supported palladium catalysts active for the gas phase hydrogenation of crotonaldehyde.

A series of five alumina-supported palladium catalysts have previously been prepared and characterised by a combination of CO chemisorption and infrared spectroscopy. The reactive attributes of these catalysts are examined using the hydrogenation of crotonaldehyde as a test reaction, using a modified infrared gas cell as a batch reactor. Periodic scanning of the infrared spectrum of the gaseous phase present over the Pd/Al(2)O(3) catalysts was used to construct reaction profiles. Four of the catalysts were able to facilitate a 2-stage hydrogenation process (crotonaldehyde → butanal → butanol), whilst one catalyst was totally selective for the first stage hydrogenation process (crotonaldehyde → butanal). Rate coefficients for the first and second stage hydrogenation processes are normalised to the number of surface palladium atoms for the particular catalyst. Correlation of these kinetic parameters as a function of mean particle size indicates the first stage process to be structure insensitive, whilst the second stage hydrogenation is structure sensitive. Chlorine residues associated with the preparative process of one of the catalysts is seen to selectively poison the second stage hydrogenation process for that catalyst. Structure/activity relationships are considered to explain the observed trends.

Adsorption and reaction of Rh(CO)2(acac) on Al2O3/Ni3Al(111).

The Al(2)O(3)/Ni(3)Al(111) surface has been used as a template for the nucleation and growth of rhodium clusters using an organometallic precursor: Rh(CO)(2)(acac). When Rh(CO)(2)(acac) is deposited on the Al(2)O(3)/Ni(3)Al(111) surface, the molecule is observed to bind preferentially to specific sites associated with the film superstructure (known as the dot structure) and appears to be stable at temperatures up to 473 K at which point some sintering and aggregation processes begin. Annealing the sample to 673 K results in further sintering of the metal deposits as well as an apparent loss in the coverage of rhodium species possibly due to a combination of desorption and deligation. After annealing to 873 K the coverage of rhodium species decreases by about 50% with respect to the initial deposited coverage. Our results suggest that using an organometallic precursor rather than metal atoms to form deposited metal particles on oxide substrates may result in increased resistance to sintering processes.

[Disabled elderly people waiting for institutionalization to a hospital ward: prospective study in the administrative district of Strasbourg (France)]. / Personnes âgées dépendantes en attente d'entrée en EHPAD depuis un service hospitalier: étude prospective sur la communauté urbaine de Strasbourg, France.

OBJECTIVES: Our aim was to estimate the number of non-satisfied instutionalization requests for inpatients and to describe the strategies elaborated to compensate for the waiting time. METHODS: This prospective follow-up study concerning all requests for institution admission for inpatients aged 75 years or older hospitalized in acute care and rehabilitation wards. Descriptive data were gathered throughout the social support process conducted during the hospitalization. A three months follow-up was conducted. RESULTS: Among 5200 hospitalizations, a social support process was initiated for 270 patients aged 75 years and over. Two thirds of the sample were women (n=163). Mean age was 82 years. Fifty-two percent of the subjects met the criteria for iso-resource grades (IRG) 1 to 2 and 90% in IRG 1 to 4. The mean length of hospitalized stay (MLOS) was 56.8+/-10.2 days; the MLOS of unjustified stay of 23.5+/-5.6 (n=222). The average time before the social worker was informed of the patient's situation was 13.6+/-2.0 days; in addition, the time required to establish the administrative documents necessary for initiation of the social support progress was 15.0+/-1.8. The principal reasons for social support were physical dependence (77%), mental dependence (60%), insufficient family support (36%) and/or disease progression (21%). At three months, 104 patients were institutionalized, 128 were still on institution waiting list (in hospital: 48%; at home: 16%) and 38 had died (14%). The estimated annual institutional deficit for disabled elderly people was 512 beds. CONCLUSION: In light of demographical perspectives, an overall re-organization of the geriatric network is absolutely necessary. A simple increase in the capacity to fulfil the institutional beds deficit would be insufficient.

Automated classification of celiac disease during upper endoscopy: Status quo and quo vadis.

A large amount of digital image material is routinely captured during esophagogastroduodenoscopies but, for the most part, is not used for confirming the diagnosis process of celiac disease which is primarily based on histological examination of biopsies. Recently, considerable effort has been undertaken to make use of image material by developing semi- or fully-automated systems to improve the diagnostic workup. Recently, focus was especially laid on developing state-of-the-art deep learning architectures, exploiting the endoscopist's expert knowledge and on making systems fully automated and thereby completely observer independent. In this work, we summarize recent trends in the field of computer-aided celiac disease diagnosis based on upper endoscopy and discuss about recent progress, remaining challenges, limitations currently prohibiting a deployment in clinical practice and future efforts to tackle them.

Soluble Vascular Cell Adhesion Molecule-1 (VCAM-1) as a Biomarker in the Mouse Model of Experimental Autoimmune Myocarditis (EAM).

Vascular cell adhesion molecule-1 (VCAM-1) is strongly upregulated in hearts of mice with coxsackie virus-induced as well as in patients with viral infection-triggered dilated cardiomyopathy. Nevertheless, the role of its soluble form as a biomarker in inflammatory heart diseases remains unclear. Therefore, we investigated whether plasma levels of soluble VCAM-1 (sVCAM-1) directly correlated with disease activity and progression of cardiac dysfunction in the mouse model of experimental autoimmune myocarditis (EAM). EAM was induced by immunization of BALB/c mice with heart-specific myosin-alpha heavy chain peptide together with complete Freund`s adjuvant. ELISA revealed strong expression of cardiac VCAM-1 (cVCAM-1) throughout the course of EAM in immunized mice compared to control animals. Furthermore, sVCAM-1 was elevated in the plasma of immunized compared to control mice at acute and chronic stages of the disease. sVCAM-1 did not correlate with the degree of acute cardiac inflammation analyzed by histology or cardiac cytokine expression investigated by ELISA. Nevertheless, heart to body weight ratio correlated significantly with sVCAM-1 at chronic stages of EAM. Cardiac systolic dysfunction studied with positron emission tomography indicated a weak relationship with sVCAM-1 at the chronic stage of the disease. Our data provide evidence that plasma levels of sVCAM-1 are elevated throughout all stages of the disease but showed no strong correlation with the severity of EAM.

Meningocortical lesion increases expression of the cholecystokinin gene in rat cerebral cortex: evidence for the involvement of platelet-activating factor (PAF).

In rat neocortex, interneurons express the gene encoding cholecystokinin. After an injury to the meninges and the underlying cortex the levels of cholecystokinin mRNA are transiently enhanced in the ipsilateral hemisphere. In the present study, we have investigated, whether platelet-activating factor plays a role in this phenomenon. Two antagonists of platelet-activating receptors, i.e. WEB 2086 (1.5 mg/kg) and brotizolam (10 mg/kg), were used. When injected 30 min prior to the injury of the parietal cortex, both agents reduced the rise in the concentration of cholecystokinin mRNA in frontal cortex by approximately 60%. They had no significant effect when given 30 min after the injury. Our finding that antagonists of platelet-activating factor receptors diminish the injury-induced change in the activity of cholecystokinin-interneurons opens the possibility that these agents may also affect other pathophysiological aspects of brain trauma.

Increase in cortical procholecystokinin gene expression induced by a meningo-cortical injury: studies on the involvement of the "immediate early gene" c-fos.

In rat cortex, a meningo-cortical injury causes complex changes in the expression of the "immediate early" genes c-fos and c-jun as well as the neuropeptide gene procholecystokinin. Within 1 h, mRNA levels of c-fos and c-jun are enhanced. Three hours later they have returned to control values. Twenty-four hours after the injury, there is a second rise in the level of c-fos-mRNA, which is accompanied by an increase in procholecystokinin-mRNA. In the present study, it was investigated whether these events are causally connected. When MK-801 (1.5 mg/kg), an ion-channel blocker, was injected 7 and 19 h after the injury, i.e. after the first rise in expression of both "immediate early" genes, it prevented the later increase in procholecystokinin-mRNA. When given 30 min prior to the injury, MK-801 (4 mg/kg) prevented the increased expression of c-fos but did not affect the later rise in procholecystokinin-mRNA. In a third experiment the cortex injury was performed in a manner which did not increase procholecystokinin-mRNA in frontal cortex. Nevertheless, expression of the c-fos gene was enhanced when determined 24 h after the operation. It is concluded that the injury-induced rise in the expression of the procholecystokinin gene is not connected with the changes in c-fos-mRNA.

Evidence for a role of noradrenergic neurons in the increase in concentration of preprocholecystokinin-mRNA after cerebral cortex injury in rats.

A knife cut injuring the meninges and the upper layers of rat neocortex transiently increases the levels of preprocholecystokinin-mRNA in the whole ipsilateral cortex. 48 h after the injury, the rise in gene expression was reduced by the edema-induced increase in tissue pressure which develops after the trauma. The beta-adrenoceptor antagonists alprenolol (4 mg/kg) and propranolol (1 mg/kg), given i.m. 30 min prior to the injury, reduced the increase by 75.6 and 100%, respectively. In contrast, blockade of alpha-adrenoceptors as well as of dopamine and serotonin receptors by respective antagonists did not affect the injury-induced increase in levels of preprocholecystokinin-mRNA. These results suggest that noradrenergic neurons can contribute via stimulation of beta-adrenoceptors to the initiation of the injury-induced increase in preprocholecystokinin gene expression.

Expression of the proenkephalin gene in cultured astroglial cells: analysis of cell cycle dependence.

Glial progenitors strongly express the proenkephalin (PEnk) gene during their proliferation in the subventricular zone of the neocortex. Also in primary culture, astroglial cells from rat neocortex produce PEnk mRNA. Since the basal expression sharply declines after the cultured cells reach confluence, it seems to be related to cell proliferation. In contrast, activation of protein kinases A and C strongly enhances the levels of PEnk mRNA in confluent cultures. Therefore, it was investigated in cultured neocortical astroglial cells, whether the basal and stimulated expression of the PEnk gene occurred during different phases of the cell cycle. Activation of protein kinases A and C with 8Br.cAMP and tetradecanoylphorbolacetate, respectively, enhanced the PEnk gene expression only during the G1 phase. Unstimulated astroglial cells contained PEnk mRNA during the G1 as well as the S phase of the cell cycle. Since confluent astroglial cells are arrested in the G1 phase, they should have a basal expression of the gene which is comparable to that in preconfluent cells. Thus, the reduced basal expression after confluence indicates that other mechanisms may play a role, such as humoral factors or contact inhibition.

Cerebral cortex injury: effect of blockers of re-uptake of catecholamines.

In rats, surgical injury of the neocortex enhances the level of procholecystokinin-mRNA in the ipsilateral cortex. This increase in procholecystokinin gene expression was significantly reduced by the blockers of catecholamine re-uptake nomifensine (4 mg/kg), cocaine (5 mg/kg) and (+)-oxaprotiline (1.5 mg/kg) given i.m. 30 min before the injury. The ganglionic blocking agent hexamethonium (3 mg/kg) prevented this effect of (+)-oxaprotiline and nomifensine. Also the alpha 1-adrenoceptor antagonists corynanthine (2 mg/kg) and prazosin (2 mg/kg) blocked this effect of (+/-)-oxaprotiline (1.5 mg/kg). It is concluded that catecholamines acting on alpha 1-adrenoceptors can reduce the increase in procholecystokinin-mRNA caused by cortex injury. The catecholamines may be released from the sympathetic nervous system.

Quality of heroin and heroin-related deaths from 1987 to 1995 in Vienna, Austria.

AIMS: To investigate the quality of heroin seized in Vienna between 1987 and 1995 and to examine whether there was a relationship between the quality of heroin and the rate of drug-related deaths. DESIGN: Reports of heroin seizure analysis and post-mortem reports of heroin-related deaths in Vienna from 1987 to 1995 were analysed. RESULTS: There were 386 seizures of heroin comprising a total weight of 25 640.12 g heroin. All the seizures were in the base form. All seizures also contained a diluent, mainly lactose. Additionally, in 95 seizures caffeine, in four seizures paracetamol and in three seizures metaqualon were detected. Of a total of 764 drug-related deaths 506 cases were classified as heroin-related deaths. In 336 cases other central nervous system-depressant drugs and/or alcohol could be detected in the blood in addition to morphine (polydrug heroin-related deaths). There was evidence of a trend towards greater polydrug involvement during the study period. The age of victims of polydrug heroin-related deaths remained unchanged over time while the age of victims of pure heroin-related deaths decreased significantly. The morphine concentration in the medulla oblongata in heroin-related deaths decreased significantly. Finally, there was no statistically significant relationship between the rate of heroin-related deaths per year and the diacetylmorphine concentration of heroin seizures in that year. CONCLUSION: The results did not substantiate the widely held belief that increases in heroin-related deaths could be explained by an increase in the quality of heroin.

Antinuclear antibodies in schizophrenia and major depressive disorder - a lasting puzzle.

Sera from patients with major depressive disorder and paranoid schizophrenia were screened for antinuclear antibodies (antigens: ds-DNA, ENA, histone H3) and circulating immune complexes (CIC-Cq1) by ELISA. Controls were healthy blood donors. Only a few of the patients' sera were positive for anti-ds-DNA and anti-ENA antibodies. There was no significant result. In paranoid schizophrenia 20.5% of sera were positive for antibodies against histone H3. In the case of CIC-Cql, 7% of the patients with major depressive disorder and 11 % of those with paranoid schizophrenia were positive. Controls showed positive sera in 39%. This study disagrees with former studies which could demonstrate a series of antinuclear antibodies in mental disorders. In the case of antihistone antibodies, the present results could indicate an autoimmune process in a subgroup of schizophrenic patients.

Selective medical image compression techniques for telemedical and archiving applications.

Selective Image Compression (SeLIC) is a compression technique where explicitly defined regions of interest (RoI) are compressed in a lossless way whereas image regions containing unimportant information are compressed in a lossy manner. Such techniques are of great interest in telemedicine or medical imaging applications with large storage requirements. In this paper we introduce and compare techniques with different functionalities. Moreover, we investigate the impact of using wavelet transforms and JPEG as underlying lossy compression algorithm.

Confidential storage and transmission of medical image data.

We discuss computationally efficient techniques for confidential storage and transmission of medical image data. Two types of partial encryption techniques based on AES are proposed. The first encrypts a subset of bitplanes of plain image data whereas the second encrypts parts of the JPEG2000 bitstream. We find that encrypting between 20% and 50% of the visual data is sufficient to provide high confidentiality.

Optical power outputs, spectra and dental composite depths of cure, obtained with blue light emitting diode (LED) and halogen light curing units (LCUs).

OBJECTIVE: To test the hypothesis that a prototype LED light curing unit, (LCU), a commercial LED LCU and a halogen LCU achieve similar cure depths, using two shades of a camphorquinone photoinitiated dental composite. To measure the LCUs' outputs and the frequency of the LED LCU's pulsed light, using a blue LED array as a photodetector. DESIGN: Cure depth and light output characterisation to compare the LCUs. SETTING: An in vitro laboratory study conducted in the UK. MATERIALS AND METHODS: The LCUs cured A2 and A4 composite shades. A penetrometer measured the depth of cure. Analysis was by one-way ANOVA, two-way univariate ANOVA and Fisher's LSD test with a 95% confidence interval. A power meter and spectrograph characterised the LCUs' emissions. A blue LED array measured the pulsed light frequency from an LED LCU. RESULTS: Statistically significant different LCU irradiances (119 mW/cm2 to 851 mW/cm2) and cure depths (3.90 mm SD +/- 0.08 to 6.68 mm SD +/- 0.07) were achieved. Composite shade affected cure depth. A blue LED array detected pulsed light at 12 Hz from the commercial LED LCU. CONCLUSIONS: The prototype LED LCU achieved a greater or equal depth of cure when compared with the commercial LCUs. LEDs may have a potential in dentistry for light detection as well as emission.

[Immediate and remote results of surgical treatment of meningioma in the area of the small wing of the sphenoid bone]. / Bezposrednie i odlegle wyniki chirurgicznego leczenia oponiaków malego skrzydla kosci klinowej.

Symptoms and therapeutic results are reported in 21 cases of the sphenoidal ridge meningiomas. These meningiomas are usually not recognized in an early stage of typical of intracranial tumours. Headaches as an early symptoms were the complaint in only 10 cases. In the stage of clinical manifestations 9 patients had no visual disturbances, in 4 cases the eye fundus was not changed, in 13 there were no visual field defects. Unilateral exophthalmos was present in 5 cases, radiological changes in 13. The first five patients operated upon under local anaesthesia were lost, but out of the remaining 16 patients operated upon under general anaesthesia only 1 died of septicaemia three weeks after the operation. A considerable facilitation of the operation was the sitting position of the patients which make possible a good insight into the operation field (Fig. 1). At the time of collecting data about the fates of the patients 10 lived without help, six of them returned to their previous occupations, and 4 other ones were partly disabled because of poor visual acuity. Two patients required continuous care because of frequent epileptic seizures. One patient had recurrence after 3 years and was treated surgically again with success.

Evaluation of different distortion correction methods and interpolation techniques for an automated classification of celiac disease.

Due to the optics used in endoscopes, a typical degradation observed in endoscopic images are barrel-type distortions. In this work we investigate the impact of methods used to correct such distortions in images on the classification accuracy in the context of automated celiac disease classification. For this purpose we compare various different distortion correction methods and apply them to endoscopic images, which are subsequently classified. Since the interpolation used in such methods is also assumed to have an influence on the resulting classification accuracies, we also investigate different interpolation methods and their impact on the classification performance. In order to be able to make solid statements about the benefit of distortion correction we use various different feature extraction methods used to obtain features for the classification. Our experiments show that it is not possible to make a clear statement about the usefulness of distortion correction methods in the context of an automated diagnosis of celiac disease. This is mainly due to the fact that an eventual benefit of distortion correction highly depends on the feature extraction method used for the classification.

Color treatment in endoscopic image classification using multi-scale local color vector patterns.

In this work we propose a novel method to describe local texture properties within color images with the aim of automated classification of endoscopic images. In contrast to comparable Local Binary Patterns operator approaches, where the respective texture operator is almost always applied to each color channel separately, we construct a color vector field from an image. Based on this field the proposed operator computes the similarity between neighboring pixels. The resulting image descriptor is a compact 1D-histogram which we use for a classification using the k-nearest neighbors classifier. To show the usability of this operator we use it to classify magnification-endoscopic images according to the pit pattern classification scheme. Apart from that, we also show that compared to previously proposed operators we are not only able to get competitive classification results in our application scenario, but that the proposed operator is also able to outperform the other methods either in terms of speed, feature compactness, or both.

Delaunay triangulation-based pit density estimation for the classification of polyps in high-magnification chromo-colonoscopy.

In this work we propose a method to extract shape-based features from endoscopic images for an automated classification of colonic polyps. This method is based on the density of pits as used in the pit pattern classification scheme which is commonly used for the classification of colonic polyps. For the detection of pits we employ a noise-robust variant of the LBP operator. To be able to be robust against local texture variations we extend this operator by an adaptive thresholding. Based on the detected pit candidates we compute a Delaunay triangulation and use the edge lengths of the resulting triangles to construct histograms. These are then used in conjunction with the k-NN classifier to classify images. We show that, compared to a previously developed method, we are not only able to almost always get higher classification results in our application scenario, but that the proposed method is also able to significantly outperform the previously developed method in terms of the computational demand.