A tunable radiation source by coupling laser-plasma-generated electrons to a periodic structure

Near-infrared radiation around 1000 nm generated from the interaction of a high-density MeV electron beam, obtained by impinging an intense ultrashort laser pulse on a solid target, with a metal grating is observed experimentally. Theoretical modeling and particle-in-cell simulation suggest that the radiation is caused by the Smith-Purcell mechanism. The results here indicate that tunable terahertz radiation with tens GV=m field strength can be achieved by using appropriate grating parameter

Predicting death and readmission after intensive care discharge

Background: Despite initial recovery from critical illness, many patients deteriorate after discharge from the intensive care unit (ICU). We examined prospectively collected data in an attempt to identify patients at risk of readmission or death after intensive care discharge. Methods: This was a secondary analysis of clinical audit data from patients discharged alive from a mixed medical and surgical (non-cardiac) ICU. Results: Four hundred and seventy-five patients (11.2%) died in hospital after discharge from the ICU. Increasing age, time in hospital before intensive care admission, Acute Physiology and Chronic Health Evaluation II (APACHE II) score, and discharge Therapeutic Intervention Scoring System (TISS) score were independent risk factors for death after intensive care discharge. Three hundred and eighty-five patients (8.8%) were readmitted to intensive care during the same hospital admission. Increasing age, time in hospital before intensive care, APACHE II score, and discharge to a high dependency unit were independent risk factors for readmission. One hundred and forty-three patients (3.3%) were readmitted within 48 h of intensive care discharge. APACHE II scores and discharge to a high dependency or other ICU were independent risk factors for early readmission. The overall discriminant ability of our models was moderate with only marginal benefit over the APACHE II scores alone. Conclusions: We identified risk factors associated with death and readmission to intensive care. It was not possible to produce a definitive model based on these risk factors for predicting death or readmission in an individual patient.Not peer reviewedAuthor versio

Long-term microcarrier suspension cultures of human embryonic stem cells

AbstractThe conventional method of culturing human embryonic stem cells (hESC) is on two-dimensional (2D) surfaces, which is not amenable for scale up to therapeutic quantities in bioreactors. We have developed a facile and robust method for maintaining undifferentiated hESC in three-dimensional (3D) suspension cultures on matrigel-coated microcarriers achieving 2- to 4-fold higher cell densities than those in 2D colony cultures. Stable, continuous propagation of two hESC lines on microcarriers has been demonstrated in conditioned media for 6 months. Microcarrier cultures (MC) were also demonstrated in two serum-free defined media (StemPro and mTeSR1). MC achieved even higher cell concentrations in suspension spinner flasks, thus opening the prospect of propagation in controlled bioreactors

Grain-filling rate improves physical grain quality in barley under heat stress conditions during the grain-filling period

Heat stress is a primary constraint to Australia's barley production. In addition to impacting grain yield, it adversely affects physical grain quality (weight and plumpness) and market value. The incidence of heat stress during grain filling is rising with global warming. However, breeding for new superior heat-tolerant genotypes has been challenging due to the narrow window of sensitivity, the unpredictable nature of heat stress, and its frequent co-occurrence with drought stress. Greater scientific knowledge regarding traits and mechanisms associated with heat tolerance would help develop more efficient selection methods. Our objective was to assess 157 barley varieties of contrasting genetic backgrounds for various developmental, agro-morphological, and physiological traits to examine the effects of heat stress on physical grain quality. Delayed sowing (i.e., July and August) increased the likelihood of daytime temperatures above 30°C during grain-filling. Supplementary irrigation of field trials ensured a reduced impact of drought stress. Heat tolerance appeared to be the primary factor determining grain plumpness. A wide variation was observed for heat tolerance, particularly among the Australian varieties. Genotypic variation was also observed for grain weight, plumpness, grain growth components, stay-green and stem water-soluble carbohydrates (WSC) content, and mobilisation under normal and delayed sown conditions. Compared to normal sowing, delayed sowing reduced duration of developmental phases, plant height, leaf size, head length, head weight, grain number, plumpness, grain width and thickness, stem WSC content, green leaf area retention, and harvest index (HI), and increased screenings, grain length, grain-filling rate (GFR), WSC mobilisation efficiency (WSCME), and grain protein content. Overall, genotypes with heavier and plumper grains under high temperatures had higher GFR, longer grain-filling duration, longer green leaf area retention, higher WSCME, taller stature, smaller leaf size, greater HI, higher grain weight/plumpness potentials, and earlier flowering. GFR played a significant role in determining barley grain weight and plumpness under heat-stress conditions. Enhancing GFR may provide a new avenue for improving heat tolerance in barley

On the Crepant Resolution Conjecture in the Local Case

In this paper we analyze four examples of birational transformations between local Calabi-Yau 3-folds: two crepant resolutions, a crepant partial resolution, and a flop. We study the effect of these transformations on genus-zero Gromov-Witten invariants, proving the Coates-Corti-Iritani-Tseng/Ruan form of the Crepant Resolution Conjecture in each case. Our results suggest that this form of the Crepant Resolution Conjecture may also hold for more general crepant birational transformations. They also suggest that Ruan's original Crepant Resolution Conjecture should be modified, by including appropriate "quantum corrections", and that there is no straightforward generalization of either Ruan's original Conjecture or the Cohomological Crepant Resolution Conjecture to the case of crepant partial resolutions. Our methods are based on mirror symmetry for toric orbifolds.Comment: 27 pages. This is a substantially revised and shortened version of my preprint "Wall-Crossings in Toric Gromov-Witten Theory II: Local Examples"; all results contained here are also proved there. To appear in Communications in Mathematical Physic

Smooth Particle Hydrodynamics-Based Characteristics of a Shaped Jet from Different Materials

The liner material is one of the key factors in the design of armor-piercing ammunition that effect the penetration efficiency. The performance of a shaped jet formed by the charge liner is determined by different properties of the material under the blasting action, in particular for the target with explosive reactive armor, which diminishes the penetration power by dispersing the shaped jet. The performance of shaped jet elements from different materials is studied, AUTODYN finite element software and smooth particle hydrodynamics method are employed to simulate the formation of shaped jet elements from the three materials: Cu, PTFE, and PTFE/Cu and their penetration into target plates, which was verified in the experiment. A shaped jet for a Cu liner is shown to be formed under the action of a detonation wave, while PTFE and PTFE/Cu materials generate a dispersive particle jet. The head velocity of a Cu jet is found to be the lowest, the penetration depth is the deepest, and the penetration hole size is the smallest; the velocity of a PTFE particle jet is the highest and the penetration depth is the shallowest, the penetration hole size takes the mid-position; the head velocity and penetration depth of a PTFE/Cu jet take the mid-position, while the penetration hole is the largest. The PTFE/Cu jet possesses higher penetration performance as compared to the PTFE jet, and its hole-opening capability is improved as compared to the Cu jet.Облицовочный материал один из ключевых факторов при создании бронебойных боеприпасов, оказывающий влияние на эффективность внедрения. Работоспособность кумулятивного заряда, формируемого его облицовкой, определяется различными свойствами материала в условиях взрывной нагрузки, в частности для мишени с элементами динамической защиты, которые уменьшают проникающую способность, рассеивая кумулятивный заряд. Изучены рабочие характеристики элементов кумулятивного заряда из различных материалов. Конечноэлементное программное обеспечение AUTODYN и метод гидродинамики гладких частиц используются при моделировании формирования этих элементов и их внедрении в пластинымишени из трех материалов: Cu, ПТФЭ и ПТФЭ/Сu, что было проверено экспериментально. Показано, что кумулятивный заряд для медной облицовки формируется под действием детонационной волны, тогда как ПТФЭ и ПТФЭ/Cu материалы генерируют струю распыленных частиц. Установлено, что в головной части скорость струи частиц Сu наименьшая, глубина внедрения наибольшая, а размер отверстий наименьший, скорость струи частиц ПТФЭ наибольшая, глубина внедрения наименьшая, размер отверстий занимает среднее положение, скорость и глубина внедрения струи частиц ПТФЭ/Сu занимают среднее положение, тогда как отверстия имеют наибольший размер. Струя частиц ПТФЭ/Сu обладает более высокой эффективностью внедрения по сравнению со струей ПТФЭ, а ее проникающая способность выше, чем струи Cu.Облицювальний матеріал - один з ключових чинників при створенні бронебійних боєприпасів, який впливає на ефективність заглиблення. Працездатність кумулятивного заряду, який формується його облицюванням, визначається різними властивостями матеріалу в умовах вибухового навантаження, зокрема для мішені з елементами динамічного захисту, які зменшують проникаючу здатність, розсіюючи кумулятивний заряд. Вивчено робочі характеристики елементів кумулятивного заряду з різних матеріалів. Скінчнноелементне програмне забезпечення AUTODYN і метод гідродинаміки гладких частинок використовуються при моделюванні формування цих елементів і їх впровадженні в пластини-мішені з трьох матеріалів: Cu, ПТФЕ і ПТФЕ / Cu, що було перевірено експериментально. Показано, що кумулятивний заряд для мідного облицювання формується під дією детонаційної хвилі, тоді як ПТФЕ і ПТФЕ / Cu матеріали генерують струмінь розпорошених частинок. Встановлено, що в головній частині швидкість струменя частинок Cu найменша, глибина заглиблення найбільша, а розмір отворів менший, швидкість струменя частинок ПТФЕ найбільша, глибина заглиблення найменша, розмір отворів займає середнє положення, швидкість і глибина заглиблення струменя частинок ПТФЕ / Cu займають середнє положення, тоді як отвори мають найбільший розмір. Струмінь частинок ПТФЕ / Cu володіє більш високою ефективністю заглиблення в порівнянні зі струменем ПТФЕ, а її проникаюча здатність вище, ніж струменя Cu

Serological response in RT-PCR confirmed h1n1-2009 influenza a by hemagglutination inhibition and virus neutralization assays: An observational study

10.1371/journal.pone.0012474PLoS ONE58