Extraction of Kinetic Parameters for the Chemical Vapor Deposition of Polycrystalline Silicon at Medium and Low Pressures

The deposition of silicon (Si) from silane (SiH4) was studied in the silane pressure range from 0.5 to 100 Pa (0.005 to1 mbar) and total pressure range from 10 to 1000 Pa using N2 or He as carrier gases. The two reaction paths, namely,heterogeneous and homogeneous decomposition could be separated by varying the amount of wafer area per unit volume(wafer-distance variation) and the SiH4 partial pressure as well as the total pressure. Rate constants were derived by fittingthe experimental results. The heterogeneous reaction path could be described by only the adsorption rate constants ofreactive species and the desorption rate constant of hydrogen using a Langmuir-Hinshelwood mechanism. Hydrogen andphosphine were found to suppress the deposition rate at low silane pressures. At high silane pressures or high totalpressures the unimolecular decomposition of silane dominates. The unimolecular rate constant was found to be one to twoorders larger than literature values based on RRKM analyses of high pressure rate data. The relative efficiency of SiH4-N2and SiH4-He collisions compared with SiH4-SiH4 collisions in the unimolecular gas-phase decomposition of SiH4 has beeninvestigated. Helium was found to be a weak collider compared to silane and nitrogen

Elevating crop disease resistance with cloned genes

Essentially all plant species exhibit heritable genetic variation for resistance to a variety of plant diseases caused by fungi, bacteria, oomycetes or viruses. Disease losses in crop monocultures are already significant, and would be greater but for applications of disease-controlling agrichemicals. For sustainable intensification of crop production, we argue that disease control should as far as possible be achieved using genetics rather than using costly recurrent chemical sprays. The latter imply CO2 emissions from diesel fuel and potential soil compaction from tractor journeys. Great progress has been made in the past 25 years in our understanding of the molecular basis of plant disease resistance mechanisms, and of how pathogens circumvent them. These insights can inform more sophisticated approaches to elevating disease resistance in crops that help us tip the evolutionary balance in favour of the crop and away from the pathogen. We illustrate this theme with an account of a genetically modified (GM) blight-resistant potato trial in Norwich, using the Rpi-vnt1.1 gene isolated from a wild relative of potato, Solanum venturii, and introduced by GM methods into the potato variety Desiree

Emotion, rationality, and decision-making: How to link affective and social neuroscience with social theory

In this paper, we argue for a stronger engagement between concepts in affective and social neuroscience on the one hand, and theories from the fields of anthropology, economics, political science, and sociology on the other. Affective and social neuroscience could provide an additional assessment of social theories. We argue that some of the most influential social theories of the last four decades-rational choice theory, behavioral economics, and post-structuralism-contain assumptions that are inconsistent with key findings in affective and social neuroscience. We also show that another approach from the social sciences-plural rationality theory-shows greater compatibility with these findings. We further claim that, in their turn, social theories can strengthen affective and social neuroscience. The former can provide more precise formulations of the social phenomena that neuroscientific models have targeted, can help neuroscientists who build these models become more aware of their social and cultural biases, and can even improve the models themselves. To illustrate, we show how plural rationality theory can be used to further specify and test the somatic marker hypothesis. Thus, we aim to accelerate the much-needed merger of social theories with affective and social neuroscience

Homogeneous, Real-Time NanoBRET Binding Assays for the Histamine H₃ and H₄ Receptors on Living Cells

Receptor-binding affinity and ligand-receptor residence time are key parameters for the selection of drug candidates and are routinely determined using radioligand competition-binding assays. Recently, a novel bioluminescence resonance energy transfer (BRET) method utilizing a NanoLuc-fused receptor was introduced to detect fluorescent ligand binding. Moreover, this NanoBRET method gives the opportunity to follow fluorescent ligand binding on intact cells in real time, and therefore, results might better reflect in vivo conditions as compared with the routinely used cell homogenates or purified membrane fractions. In this study, a real-time NanoBRET-based binding assay was established and validated to detect binding of unlabeled ligands to the histamine H3 receptor (H3R) and histamine H4 receptor on intact cells. Obtained residence times of clinically tested H3R antagonists were reflected by their duration of H3R antagonism in a functional receptor recovery assay

Potential for improvement of docetaxel-based chemotherapy: a pharmacological review

Since the introduction of docetaxel, research has focused on various approaches to overcome treatment limitations and improve outcome. This review discusses the pharmacological attempts at treatment optimisation, which include reducing interindividual pharmacokinetic and pharmacodynamic variability, optimising schedule, route of administration, reversing drug resistance and the development of structurally related second-generation taxanes

Metachronous bladder metastases from renal cell carcinoma: a case report and review of the literature

INTRODUCTION: adrenal gland, parotid gland, pharynx, eye and bladder are rare localizations of metastases of renal cell carcinoma (RCC). We report a case of metachronous RCC metastases to the bladder in a patient with a medical history of transitional cell carcinoma (TCC) of the bladder. MATERIALS AND METHODS: a case study and review of the relevant literature are presented. RESULTS: during a follow-up cystoscopy examination following treatment of TCC, a single 5-mm lesion was detected and endoscopically resected. The histology of the resected sample was confirmed to be RCC, comparable to a primary kidney cancer and not recurrent TCC. CONCLUSION: the patient had a probability of metastases three years after nephrectomy of 62.9%. Survival rates following single metastasectomy are 60% and 38% at three and five years, respectively; metachronous diagnosis has a better prognosis than synchronous. During RCC follow-up, each lesion should be considered as a possible metastasis of RCC

A Multistage Stochastic Programming Approach to the Dynamic and Stochastic VRPTW - Extended version

We consider a dynamic vehicle routing problem with time windows and stochastic customers (DS-VRPTW), such that customers may request for services as vehicles have already started their tours. To solve this problem, the goal is to provide a decision rule for choosing, at each time step, the next action to perform in light of known requests and probabilistic knowledge on requests likelihood. We introduce a new decision rule, called Global Stochastic Assessment (GSA) rule for the DS-VRPTW, and we compare it with existing decision rules, such as MSA. In particular, we show that GSA fully integrates nonanticipativity constraints so that it leads to better decisions in our stochastic context. We describe a new heuristic approach for efficiently approximating our GSA rule. We introduce a new waiting strategy. Experiments on dynamic and stochastic benchmarks, which include instances of different degrees of dynamism, show that not only our approach is competitive with state-of-the-art methods, but also enables to compute meaningful offline solutions to fully dynamic problems where absolutely no a priori customer request is provided.Comment: Extended version of the same-name study submitted for publication in conference CPAIOR201