Sun Yat-sen University

About: Sun Yat-sen University is a education organization based out in Guangzhou, Guangdong, China. It is known for research contribution in the topics: Population & Cancer. The organization has 115149 authors who have published 113763 publications receiving 2286465 citations. The organization is also known as: Zhongshan University & SYSU.

The Role of Imaging in the Detection and Management of COVID-19: A Review

Abstract: Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is spreading rapidly around the world, resulting in a massive death toll. Lung infection or pneumonia is the common complication of COVID-19, and imaging techniques, especially computed tomography (CT), have played an important role in diagnosis and treatment assessment of the disease. Herein, we review the imaging characteristics and computing models that have been applied for the management of COVID-19. CT, positron emission tomography - CT (PET/CT), lung ultrasound, and magnetic resonance imaging (MRI) have been used for detection, treatment, and follow-up. The quantitative analysis of imaging data using artificial intelligence (AI) is also explored. Our findings indicate that typical imaging characteristics and their changes can play crucial roles in the detection and management of COVID-19. In addition, AI or other quantitative image analysis methods are urgently needed to maximize the value of imaging in the management of COVID-19.

Piezofluorochromism of an aggregation-induced emission compound derived from tetraphenylethylene.

Abstract: The development of organic fluorescence materials is of great interest for both fundamental research and practical applications. The modification or alteration of molecular chemical structures is the most-common approach for controlling fluorescence properties. However, there are a limited number of effective materials for the dynamic control of solid-state fluorescence with high efficiency and reversibility, because most chemical reactions in the solid state involve insufficient conversion and irreversible reactions, or result in the loss of fluorescence capability. To overcome this problem, a very attractive approach is proposed which dynamically controls solid fluorescence properties by altering the mode of solid-state molecular stacking without changing the chemical structure of the constituting molecules. Found recently, piezofluorochromism is a change in the fluorescence color induced by mechanical stress, accompanied with a reversion to the original fluorescent color by heating, recrystallization, or exposure to solvent vapor. Many piezochromic materials have been reported based on the change in absorption characteristics under pressure. Fluorescence can be detected with high sensitivity, thus enabling materials with piezofluorochromism to have a wide variety of applications in optical recording and strainor pressure-sensing systems. However, organic piezofluorochromic materials are exceedingly rare. Recently, many aggregation-induced emission (AIE) compounds with various chemical structures have been synthesized in our laboratory, and it is very interesting to find that almost all of these compounds are piezofluorochromic materials. We would thus suggest calling these compounds piezofluorochromic aggregation-induced emission (PAIE) materials as they possess both piezofluorochromic and aggregation-induced emission properties. Aggregation-induced emission materials, first reported by Tang and co-workers, are one of an important class of luminescent materials and exhibit many special properties, such as strong solid emission, excellent device performance, and highly stimuli-sensitive fluorescence. PAIE materials have the advantages of both piezofluorochromic materials and aggregation-induced emission materials and can be more-widely used. However, to the best of our knowledge, there has been only one compound (DBDCS, Scheme 1 c) that has both piezofluorochro-

Performance of missing transverse momentum reconstruction in proton-proton collisions at√s = 7 TeV with atlas

Abstract: The measurement of missing transverse momentum in the ATLAS detector, described in this paper, makes use of the full event reconstruction and a calibration based on reconstructed physics objects. The performance of the missing transverse momentum reconstruction is evaluated using data collected in pp collisions at a centre-of-mass energy of 7 TeV in 2010. Minimum bias events and events with jets of hadrons are used from data samples corresponding to an integrated luminosity of about 0.3 nb(-1) and 600 nb(-1) respectively, together with events containing a Z boson decaying to two leptons (electrons or muons) or a W boson decaying to a lepton (electron or muon) and a neutrino, from a data sample corresponding to an integrated luminosity of about 36 pb(-1). An estimate of the systematic uncertainty on the missing transverse momentum scale is presented.

Genetic Structure of the Han Chinese Population Revealed by Genome-wide SNP Variation

Abstract: Population stratification is a potential problem for genome-wide association studies (GWAS), confounding results and causing spurious associations. Hence, understanding how allele frequencies vary across geographic regions or among subpopulations is an important prelude to analyzing GWAS data. Using over 350,000 genome-wide autosomal SNPs in over 6000 Han Chinese samples from ten provinces of China, our study revealed a one-dimensional "north-south" population structure and a close correlation between geography and the genetic structure of the Han Chinese. The north-south population structure is consistent with the historical migration pattern of the Han Chinese population. Metropolitan cities in China were, however, more diffused "outliers," probably because of the impact of modern migration of peoples. At a very local scale within the Guangdong province, we observed evidence of population structure among dialect groups, probably on account of endogamy within these dialects. Via simulation, we show that empirical levels of population structure observed across modern China can cause spurious associations in GWAS if not properly handled. In the Han Chinese, geographic matching is a good proxy for genetic matching, particularly in validation and candidate-gene studies in which population stratification cannot be directly accessed and accounted for because of the lack of genome-wide data, with the exception of the metropolitan cities, where geographical location is no longer a good indicator of ancestral origin. Our findings are important for designing GWAS in the Chinese population, an activity that is expected to intensify greatly in the near future.