61 research outputs found

    Cтруктурні, оптичні і термоелектричні властивості плівок та наночастинок ZnO, CZTS, CZTSe для фото- і термоперетворювачів

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    Дисертаційна робота присвячена оптимізації основних фотоелектричних характеристик, а саме квантового виходу (Q), густини струму короткого замикання (Jsc), ефективності (η) плівкових ФЕП на основі ГП n-CdS(ZnSe, ZnS)/p-(CZTS, CdTe) із струмознімальними контактами n-ITO(ZnO); дослідженню морфологічних особливостей, структурних, субструктурних, оптичних, термоелектричних властивостей та елементного складу плівок ZnO, CZTS, нанесених методом пульсуючого спрей піролізу, для використання у ФЕП та наноструктурованого матеріалу на основі НЧ CZTSe, синтезованих колоїдним методом, для застосування у ТЕП, що можуть працювати паралельно з ФЕП. Встановлені взаємозв’язки між фізико- та хіміко-технологічними умовами нанесення плівок та синтезу НЧ, наноструктурованого матеріалу на їх основі, та структурними, субструктурними, оптичними, термоелектричними властивостями, елементним складом будуть використані для подальшого створення ФЕП та ТЕП з покращеними характеристиками.Диссертационная работа посвящена оптимизации основных фотоэлектрических характеристик, а именно квантового выхода (Q), плотности тока короткого замыкания (Jsc), эфективности (η) плёночных ФЭП на основе ГП n-CdS(ZnSe, ZnS)/p-(CZTS, CdTe) с токособирающими контактами ITO(ZnO); исследованию морфологических особенностей, структурных, субструктурных, оптических, термоэлектрических свойств и элементного состава плёнок ZnO, CZTS, нанесённых методом пульсирующего спрей-пиролиза, для применения у вышеуказанных ФЭП и наноструктурированного материала на основе НЧ CZTSe, синтезированных колоидальным методом, для использования у ТЭП, которые могут работать паралельно с ФЭП. Установленные взаимосвязи между физико- и химико-технологическими условиями нанесения плёнок, синтеза НЧ, наноструктурированного материала на их основе, и структурными, субструктурными, оптическими, термоэлектрическими свойствами, элементным составом будут использованы для создания ФЭП и ТЭП с улучшенными характеристиками.PhD thesis is devoted both to the optimization of basic photoelectric characteristics (quantum yield (Q), density of short circuit current (Jsc), efficiency (η)) of solar cells based on n-CdS(ZnSe, ZnS)/p-(CZTS, CdTe) heterojunctions with n-ITO(ZnO) frontal contacts, and to the investigation of morphological, structural, substructural, optical, thermoelectric properties and chemical composition of: (I) ZnO, CZTS films deposited by spray pyrolysis for application in solar cells; (II) nanostructured materials based on CZTSe nanocrystals synthesized by colloidal method for application in thermoelectric devices which can work simultaneously with solar cells. In the work, modeling approbation was performed by means of investigating the effect of optical and recombination losses on Q, Jsc, η of solar cells based on n-CdS(ZnS)/p-CdTe heterojunctions. Afterwards, the investigation of these losses on the photoelectric characteristics of solar cells based on n-CdS(ZnSe, ZnS)/p-CZTS heterojunctions with n-ITO(ZnO) frontal contacts was carried out with the help of the approbated procedure. Taking into account the results of mathematical modeling, the solar cells based on ZnO frontal contact and CZTS absorber layer were considered. For this purpose, the automated setup for the deposition of ZnO and CZTS films by pulsed spray pyrolysis technique was developed. The in-depth investigation of influence of the main growth conditions of layers’ deposition (substrate temperature (Ts), volume of initial precursor (Vs)) on structural (grains size, phase composition, texture quality, lattice parameters), substructural (coherent scattering domain sizes, level of microdeformations and microstresses, density of dislocations at the boundaries and in the volume of subgrains), optical (transmission coefficients, absorbance, band gap) properties and chemical composition of ZnO, CZTS films, as well as the determination of optimal conditions to obtain the specified films were carried out. Since the solar cells operate at the elevated temperatures, it was proposed to use the additional thermal energy by means of its conversion into electrical energy by use of the thermoelectric devices. For this purpose, the nanostructured thermoelectric material based on CZTSe nanocrystals synthesized by the colloidal method was obtained. The influence of kinetic conditions, namely type of phosphonic acid, on morphological (size, shape), structural (phase composition), optical (absorbance, band gap) properties and chemical composition of CZTSe nanocrystals was determined. The influence of chemical composition on the main thermoelectric properties (concentration (p) and mobility ( u ) of majority charge carriers, relative electrical conductivity ( k ), Seebeck coefficient (SZ)) of nanostructured material based on CZTSe nanocrystals was investigated. The established correlations between the film, nanocrystals growth conditions and structural, substructural, optical, thermoelectric properties, chemical composition will be applied for further development of solar cells and thermoelectric devices with the enhanced characteristics

    Clinical management of women with metastatic breast cancer: a descriptive study according to age group

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    BACKGROUND: The primary aim of treatment of a patient who has developed metastatic disease is palliation. The objectives of the current study are to describe and quantify the clinical management of women with metastatic breast cancer from the diagnosis of metastatic disease until death and to analyze differences between age groups. METHODS: Data were collected from the medical files of all patients (n = 116) who had died after December 31, 1999, after a diagnosis of metastatic breast cancer in two teaching hospitals in the south of the Netherlands. RESULTS: Of the 116 patients included in our study, 10 (9%) already had metastatic disease at diagnosis and 106 developed distant disease after the diagnosis of localized breast cancer. Before they died, 70% of the 116 patients developed metastases in one or more bones, 50% in the lung and/or pleura, 50% in the abdominal viscera, 23% in the central nervous system, and 19% in the skin. Patients younger than 50 years were much more likely to develop metastases in the central nervous system than patients 50 years and older. Seventy-seven (66%) of the 116 patients with metastatic breast cancer received chemotherapy. This proportion decreased with age (p = 0.005), as did the number of schemes per patient. Together, they received 132 chemotherapy schemes, of which 35 (27%) resulted in partial remission or stabilization of the disease process. Ninety-eight patients (84%) received hormonal treatment. This proportion did not differ between the three age groups. Together, they received 216 hormonal treatments, 38 (16%) of which resulted in partial remission or stabilization of the disease process. Seventy-nine patients (68%) received palliative radiotherapy. This proportion decreased with age (p = 0.03). Together, they underwent 216 courses, 176 (77%) of which resulted in relief of the complaints. CONCLUSION: Patients aged 70 years and older are less likely to receive chemotherapy or radiotherapy. Part of this difference could be explained by their shorter survival time after the diagnosis of metastatic disease and their lower risk of developing brain and bone metastases. However, more research is needed to understand the age-related differences in the treatment of metastatic breast cancer, and especially how comorbidity and frailty limit therapeutic choices

    Cerebellar Zones: A Personal History

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    Cerebellar zones were there, of course, before anyone noticed them. Their history is that of young people, unhindered by preconceived ideas, who followed up their observations with available or new techniques. In the 1960s of the last century, the circumstances were fortunate because three groups, in Leiden, Lund, and Bristol, using different approaches, stumbled on the same zonal pattern in the cerebellum of the cat. In Leiden, the Häggqvist myelin stain divulged the compartments in the cerebellar white matter that channel the afferent and efferent connections of the zones. In Lund, the spino-olivocerebellar pathways activated from individual spinal funiculi revealed the zonal pattern. In Bristol, charting the axon reflex of olivocerebellar climbing fibers on the surface of the cerebellum resulted in a very similar zonal map. The history of the zones is one of accidents and purposeful pursuit. The technicians, librarians, animal caretakers, students, secretaries, and medical illustrators who made it possible remain unnamed, but their contributions certainly should be acknowledged

    Cerebellar Modules and Their Role as Operational Cerebellar Processing Units

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    The compartmentalization of the cerebellum into modules is often used to discuss its function. What, exactly, can be considered a module, how do they operate, can they be subdivided and do they act individually or in concert are only some of the key questions discussed in this consensus paper. Experts studying cerebellar compartmentalization give their insights on the structure and function of cerebellar modules, with the aim of providing an up-to-date review of the extensive literature on this subject. Starting with an historical perspective indicating that the basis of the modular organization is formed by matching olivocorticonuclear connectivity, this is followed by consideration of anatomical and chemical modular boundaries, revealing a relation between anatomical, chemical, and physiological borders. In addition, the question is asked what the smallest operational unit of the cerebellum might be. Furthermore, it has become clear that chemical diversity of Purkinje cells also results in diversity of information processing between cerebellar modules. An additional important consideration is the relation between modular compartmentalization and the organization of the mossy fiber system, resulting in the concept of modular plasticity. Finally, examination of cerebellar output patterns suggesting cooperation between modules and recent work on modular aspects of emotional behavior are discussed. Despite the general consensus that the cerebellum has a modular organization, many questions remain. The authors hope that this joint review will inspire future cerebellar research so that we are better able to understand how this brain structure makes its vital contribution to behavior in its most general form

    Breast Cancer in Young Women: Poor Survival Despite Intensive Treatment

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    The general aim of the thesis was to gain increased insight into the long-term prognosis for young women with breast cancer. In a population-based cohort of 22,017 women with breast cancer, we studied prognosis by age. Women aged <35 (n=471), 35–39 (n=858) and 40–49 (n=4789) were compared with women aged 50–69. The cumulative 5-year relative survival ratio (RSR) and the relative excess risk (RER) of mortality were calculated. Women <35 years of age had a worse survival than middle-aged women, partly explained by a later stage at diagnosis. After correction for stage, tumor characteristics and treatment, young age remained an independent risk factor for death. The excess risk of death in young women was only present in stage I-II disease and was most pronounced in women with small tumors. For in-depth studies on a large subpopulation from the original cohort (all 471 women aged <35 and a random sample of 700 women aged 35–69), we collected detailed data from the medical records, re-evaluated slides and produced TMAs from tumor tissue. Breast cancer- specific survival (BCSS), distant disease-free survival (DDFS) and locoregional recurrence- free survival (LRFS) by age were analysed. In a multivariate analysis, age <35 and age 35– 39 years conferred a risk in LRFS but not in DDFS and BCSS. The age-related differences in prognosis were most pronounced in early stage luminal Her2-negative tumors, where low age was an independent prognostic factor also for DDFS (HR 1.87 (1.03–3.44)). To study the importance of proliferation markers for the long-term prognosis in young women, protein expression of Ki-67, cyclin A2, B1, D1 and E1 was analysed in 504 women aged <40 and in 383 women aged ≥40. The higher expression of proliferation markers in young women did not have a strong impact on the prognosis. Proliferation markers are less important in young women, and Ki-67 was prognostic only in young women with Luminal PR+ tumors. Age <40 years was an independent risk factor of DDFS exclusively in this subgroup (adjusted HR 2.35 (1.22-4.50)). The only cyclin adding prognostic value beyond subtype in young women was cyclin E1. In a cohort of 469 women aged <40 and 360 women aged ≥40 we examined whether Her2 status assessed by silver enhanced in situ hybridization (SISH) for all cases, would reveal a proportion of women undiagnosed by routine Her2 testing and whether this would affect their prognosis. With SISH testing for all women, the Her2-positive rate increased from 20.0% to 24.4% (p<0.001), and similarly for women aged <40 and ≥40 years. Young women had Her2+ breast cancer twice as often as middle-aged women. Her2 amplification was present in 4.6% of cases scored 0 with IHC, while the corresponding proportions for scores 1+, 2+ and 3+ were 36.0%, 83.7% and 96.8%, respectively. All Her2 amplified cases, both true positive and false negative, had a significantly worse BCSS than the true negative cases

    Visuomotor Cerebellum in Human and Nonhuman Primates

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    In this paper, we will review the anatomical components of the visuomotor cerebellum in human and, where possible, in non-human primates and discuss their function in relation to those of extracerebellar visuomotor regions with which they are connected. The floccular lobe, the dorsal paraflocculus, the oculomotor vermis, the uvula–nodulus, and the ansiform lobule are more or less independent components of the visuomotor cerebellum that are involved in different corticocerebellar and/or brain stem olivocerebellar loops. The floccular lobe and the oculomotor vermis share different mossy fiber inputs from the brain stem; the dorsal paraflocculus and the ansiform lobule receive corticopontine mossy fibers from postrolandic visual areas and the frontal eye fields, respectively. Of the visuomotor functions of the cerebellum, the vestibulo-ocular reflex is controlled by the floccular lobe; saccadic eye movements are controlled by the oculomotor vermis and ansiform lobule, while control of smooth pursuit involves all these cerebellar visuomotor regions. Functional imaging studies in humans further emphasize cerebellar involvement in visual reflexive eye movements and are discussed

    The Magnitude of Global Marine Species Diversity

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    Background: The question of how many marine species exist is important because it provides a metric for how much we do and do not know about life in the oceans. We have compiled the first register of the marine species of the world and used this baseline to estimate how many more species, partitioned among all major eukaryotic groups, may be discovered. Results: There are ∼226,000 eukaryotic marine species described. More species were described in the past decade (∼20,000) than in any previous one. The number of authors describing new species has been increasing at a faster rate than the number of new species described in the past six decades. We report that there are ∼170,000 synonyms, that 58,000–72,000 species are collected but not yet described, and that 482,000–741,000 more species have yet to be sampled. Molecular methods may add tens of thousands of cryptic species. Thus, there may be 0.7–1.0 million marine species. Past rates of description of new species indicate there may be 0.5 ± 0.2 million marine species. On average 37% (median 31%) of species in over 100 recent field studies around the world might be new to science. Conclusions: Currently, between one-third and two-thirds of marine species may be undescribed, and previous estimates of there being well over one million marine species appear highly unlikely. More species than ever before are being described annually by an increasing number of authors. If the current trend continues, most species will be discovered this century

    Sentinel node micrometastases in breast cancer do not affect prognosis: a population-based study

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    International audienceSentinel node biopsy (SNB) for axillary staging in breast cancer allows the application of more extensive pathologic examination techniques. Micrometastases are being detected more often, however, coinciding with stage migration. Besides assessing the prognostic relevance of micrometastases and the need for administering adjuvant systemic and regional therapies, there still seems to be room for improvement. In a population-based analysis, we compared survival of patients with sentinel node micrometastases with those with node-negative and node-positive disease in the era after introduction of SNB. Data from the population-based Eindhoven Cancer Registry were used on all ( = 6803) women who underwent SNB for invasive breast cancer in the Southeast Region of The Netherlands in the period 1996-2006. In 451 patients (6.6%) a sentinel node micrometastasis (pN1mi) was detected and in 126 patients (1.9%) isolated tumor cells (pN0(i+)). Micrometastases or isolated tumor cells in the SNB did not convey any significant survival difference compared with node-negative disease. After adjustment for age, pT, and grade, still no survival difference emerged pN1mi: [HR 0.9 (95% CI, 0.6-1.3)] and pN0(i+): [HR 0.4 (95% CI, 0.14-1.3)] and neither was the case after additional adjustment for adjuvant systemic therapy. Our practice-based study showed that the presence of sentinel node micrometastases in breast cancer patients has hardly any impact on breast cancer overall survival during the first years after diagnosis
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