University of Lisbon

About: University of Lisbon is a education organization based out in Lisbon, Lisboa, Portugal. It is known for research contribution in the topics: Population & European union. The organization has 19122 authors who have published 48503 publications receiving 1102623 citations. The organization is also known as: Universidade de Lisboa & Lisbon University.

Near-GeV Acceleration of Electrons by a Nonlinear Plasma Wave Driven by a Self-Guided Laser Pulse

Abstract: The acceleration of electrons to approximately 0.8 GeV has been observed in a self-injecting laser wakefield accelerator driven at a plasma density of 5.5x10(18) cm(-3) by a 10 J, 55 fs, 800 nm laser pulse in the blowout regime. The laser pulse is found to be self-guided for 1 cm (>10zR), by measurement of a single filament containing >30% of the initial laser energy at this distance. Three-dimensional particle in cell simulations show that the intensity within the guided filament is amplified beyond its initial focused value to a normalized vector potential of a0>6, thus driving a highly nonlinear plasma wave.

Lignans and isoflavonoids in plasma and prostatic fluid in men: Samples from Portugal, Hong Kong, and the United Kingdom

Abstract: BACKGROUND Chinese men have lower incidences of prostate cancer compared to men from Europe and North America. Asians consume large quantities of soya, a rich source of isoflavanoids phyto-oestrogens and have high plasma and urinary levels of these compounds. The mammalian lignans, enterolactone and enterodiol, are another group of weak plant oestrogens and are derived from seeds, cereals and grains. Vegetarians have high plasma and urinary concentrations of lignans. METHODS The concentrations lignans and isoflavonic phyto-oestrogens were determined by gas chromatography-mass spectrometry (GC-MS) in plasma and prostatic fluid from Portuguese, Chinese and British men consuming their traditional diets. RESULTS In prostatic fluid the mean concentrations of enterolactone wer 31, 162 and 20.3ng/ml for Hong Kong, Portugal and Britain respectively. Very high levels of enterolactone (〉600ng/ml) were observed in the prostatic fluid of some of the men fromPortugal. High concentrations of equol (3270 ng/ml) and daidzein (532 ng/ml) were found in a sample of prostatic fluid from Hong Kong. Higher mean levels of daidzein were observed in prostatic fluid from Hong Kong at 70ng/ml, compared to 4.6 and 11.3ng/ml in samples from Portugal and Britain respectively. Mean levels of daidzein were higher in the plasma samples from Hong Kong (31.3ng/ml) compared to those from Portugal (1.3ng/ml) and Britain (8.2ng/ml). In general, the mean plasma concentrations of enterolactone from the three centres were similar, at 6.2, 3.9 and 3.9ng/ml in samples from Hong Kong, Portugal and Britain respectively. CONCLUSIONS Higher concentrations of the isoflavanoid phyto-oestrogens, daidzein and equol, were found in the plasma and prostatic fluid of men from Hong Kong, compared to those from Britain and Portugal. However, the levels of the lignan, enterolactone, were very much higher in prostatic fluid of Portuguese men. Isoflavanoids and lignans have many interesting properties and may, in part, be responsible for lower incidences of prostate cancer in men from Asia and also some Mediterranean countries. The isoflavanoids from soya, which are present in high concentrations in the prostatic fluid of Asian men, may be protective against prostate disease. Prostate 32:122–128, 1997. ©1997 Wiley-Liss, Inc.

Towards the sustainable discovery and development of new antibiotics

Abstract: An ever-increasing demand for novel antimicrobials to treat life-threatening infections caused by the global spread of multidrug-resistant bacterial pathogens stands in stark contrast to the current level of investment in their development, particularly in the fields of natural-product-derived and synthetic small molecules. New agents displaying innovative chemistry and modes of action are desperately needed worldwide to tackle the public health menace posed by antimicrobial resistance. Here, our consortium presents a strategic blueprint to substantially improve our ability to discover and develop new antibiotics. We propose both short-term and long-term solutions to overcome the most urgent limitations in the various sectors of research and funding, aiming to bridge the gap between academic, industrial and political stakeholders, and to unite interdisciplinary expertise in order to efficiently fuel the translational pipeline for the benefit of future generations.

Toward High-Performance Amorphous GIZO TFTs

Abstract: This work analyzes the role of processing parameters on the electrical performance of GIZO (Ga 2 O 3 :In 2 O 3 :ZnO) films and thin-film transistors (TFTs). Parameters such as oxygen partial pressure, deposition pressure, target composition, thickness, and annealing temperature are studied. Generally, better devices are obtained when low oxygen partial pressure is used. This is related to the damage induced by oxygen ion bombardment and very high film's resistivity when higher oxygen partial pressures are used. Low deposition pressures and targets with richer indium compositions led to films with high carrier concentration, resulting in transistors with field-effect mobility as high as ∼ 80 cm 2 /Vs but poor channel conductivity modulation, becoming ineffective as switching devices. Nevertheless, it is demonstrated that reducing the GIZO thickness from 40 to 10 nm greatly enhances the switching behavior of those devices, due to the lower absolute number of free carriers and hence to their easier depletion. Annealing also proves to be crucial to control device performance, significantly modifying GIZO electrical resistivity and promoting local atomic rearrangement, being the optimal temperature determined by the as-produced films' properties. For the best-performing transistors, even with a low annealing temperature (150°C), remarkable properties such as μ FE = 73.9 cm 2 /Vs, on/off ratio as 7 × 10 7 , V T ≈ 0.2 V, and S = 0.29 V/dec are achieved.