Hydrosomes: femtoliter containers for fluorescence spectroscopy studies

We report on improvements and innovations in the use of hydrosomes to encapsulate and study single molecules. Hydrosomes are optically-trappable aqueous nanodroplets. The droplets are suspended in a fluorocarbon medium that is immiscible with water and has an index of refraction lower than water, so hydrosomes are stable and optically trapped by a focused laser beam (optical tweezers). Using optical tweezers, we hold the hydrosomes within a confocal observation volume and interrogate the encapsulated molecule by fluorescence excitation. This method allows for long observation times of a molecule without the need for surface immobilization or liposome encapsulation. We have developed a new way for creating hydrosomes on demand by inertially launching them into the fluorocarbon matrix using a piezo-activated micropipette. Time-resolved fluorescence anisotropy studies are carried out to characterize the effects of the hydrosome interface boundary on biological molecules and to determine whether molecules encapsulated within hydrosomes diffuse freely throughout the available volume. We measured the fluorescence anisotropy decay of 20mer DNA duplexes, and enhanced green fluorescent protein (GFP). We conclude that the molecules rotate freely inside the nanodroplets and do not stick or aggregate at the boundary

Hydrosomes: femtoliter containers for fluorescence spectroscopy studies

We report on improvements and innovations in the use of hydrosomes to encapsulate and study single molecules. Hydrosomes are optically-trappable aqueous nanodroplets. The droplets are suspended in a fluorocarbon medium that is immiscible with water and has an index of refraction lower than water, so hydrosomes are stable and optically trapped by a focused laser beam (optical tweezers). Using optical tweezers, we hold the hydrosomes within a confocal observation volume and interrogate the encapsulated molecule by fluorescence excitation. This method allows for long observation times of a molecule without the need for surface immobilization or liposome encapsulation. We have developed a new way for creating hydrosomes on demand by inertially launching them into the fluorocarbon matrix using a piezo-activated micropipette. Time-resolved fluorescence anisotropy studies are carried out to characterize the effects of the hydrosome interface boundary on biological molecules and to determine whether molecules encapsulated within hydrosomes diffuse freely throughout the available volume. We measured the fluorescence anisotropy decay of 20mer DNA duplexes, and enhanced green fluorescent protein (GFP). We conclude that the molecules rotate freely inside the nanodroplets and do not stick or aggregate at the boundary

Diversity patterns and conservation gaps of Magnoliaceae species in China

Postponed access: the file will be available after 2023-12-27Magnoliaceae, a primitive group of angiosperms and distinguished ornamental plants with more than 100 species in China, is one of the most threatened plant family in the wild due to logging, habitat loss, over-collection and climate change. To provide a scientific guide of its conservation for policymakers, we explore the diversity patterns of 114 Magnoliaceae species in China using three diversity indices (species richness, weighted endemism, β-diversity) with a spatial resolution of 10 km by 10 km. Two methods, the top 5% richness algorithm and complementary algorithm, are used to identify diversity hotspots. Conservation gaps are recognized by overlapping the diversity hotspots with Chinese nature reserves. Our results indicate that Magnoliaceae species richness and weighted endemism are high in tropical to subtropical low montane forests in southern China, exceptionally high in southernmost Yunnan and boundary of Guizhou, Guangxi and Hunan. The β-diversity are scattered in southern China, suggesting a different species composition among grid cells. We identify 2524 grids as diversity hotspots for Magnoliaceae species in China, with 24 grids covered by three diversity indices (first-level diversity hotspots), 561 grids covered by two indices (second-level diversity hotspots) simultaneously and 1939 grids (76.8%) covered by only one index (third-level diversity hotspots). The first-level diversity hotspots include over 70% of the critically endangered Magnoliaceae species and are the priority areas for Magnoliaceae conservation. However, only 24% of the diversity hotspots fall in nature reserves and only ten grids are from the first-level diversity hotspots. Zhejiang, Guizhou and Fujian have less than 20% of diversity hotspots covered by nature reserves and need attention in future Magnoliaceae conservation. Using multiple diversity indices and algorithms, our study identifies diversity hotspots and conservation gaps and provides scientific basis for Magnoliaceae conservation in future.acceptedVersio

The Relationship Between Stroke Patients Characteristics and Family Support with Compliance Rehabilitation

Stroke is a cerebrovascular disease, it is brain function disorders associated with the disease of the blood vessels that supply the brain. The impact of stroke is paralysis. Family support is things that are needed to be considered in the treatment of stroke patients. It is very involved in the compliance rehabilitation of patients to prevent the re-occurrence of stroke. Characteristics of stroke patients may also affect the compliance rehabilitation. The purpose of this research is to determine the relationship between stroke patients characteristics and family support to compliance rehabilitation at the Medical Rehabilitation Unit RSU Haji Surabaya. This research was an analytic observational research with cross sectional design. The subjects of this research are taken using total population technique. The independent variables in this research is family support. The dependent variable is compliance rehabilitation. The results of this research are presented in the form of frequency distributions and calculate the strength of the relationship with Phi coefficient. The result of this research shows that there is a strong relationship between family support and compliance rehabilitation (r=0.582). There are weak relationship between ages (r=-0,027), gender (r=0,092), level of education (r= -0,295), work (r=0,098), and marital status (r=0,319). The conclusion is family support may affect compliance rehabilitation of stroke patients. It is recommended for health workers to provide counseling to improve family support in curing stroke patients

Prediction method of surface subsidence due to underground coal gasification under thermal coupling

Underground coal gasification (UCG) is an essential part of the low-carbon green coal mining technology system. The implementation of the “double carbon” goal of the coal industry has brought excellent development opportunities for UCG. However, UCG will also cause rock movement and surface deformation, resulting in serious threat to safety of ground buildings (structures) when use UCG to recover the “three under” coal that is difficult to mine by underground mining methods. How to accurately predict the subsidence considering characteristics of UCG has become one of the critical bottlenecks limiting the industrial application of UCG. Based on this, combined with the characteristics of ‘strip mining-surface mining’ backward UCG process, this paper explores the causes of surface subsidence caused by UCG under the thermal coupling, and concludes that the root of surface subsidence caused by UCG is the deflection of rock strata and the compression deformation of coking barrier coal pillar. Further, the calculation method of deflection deformation of UCG roof under thermal-mechanical coupling is established, and the yield model and compression calculation method of gasification coal pillar based on D-P criterion are proposed. Then, according to the principle of equivalent subsidence space, an accurate prediction model of surface subsidence of UCG under thermal coupling is constructed, and the effectiveness and accuracy of the new method are verified by the measured data of UCG in Ulanqab. The research results have important practical significance for promoting the recovery of difficult-to-mine “three under” coal resources and the industrialization for UCG

Reflective imaging improves spatiotemporal resolution and collection efficiency in light sheet microscopy

© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Nature Communications 8 (2017): 1452, doi:10.1038/s41467-017-01250-8.Light-sheet fluorescence microscopy (LSFM) enables high-speed, high-resolution, and gentle imaging of live specimens over extended periods. Here we describe a technique that improves the spatiotemporal resolution and collection efficiency of LSFM without modifying the underlying microscope. By imaging samples on reflective coverslips, we enable simultaneous collection of four complementary views in 250 ms, doubling speed and improving information content relative to symmetric dual-view LSFM. We also report a modified deconvolution algorithm that removes associated epifluorescence contamination and fuses all views for resolution recovery. Furthermore, we enhance spatial resolution (to <300 nm in all three dimensions) by applying our method to single-view LSFM, permitting simultaneous acquisition of two high-resolution views otherwise difficult to obtain due to steric constraints at high numerical aperture. We demonstrate the broad applicability of our method in a variety of samples, studying mitochondrial, membrane, Golgi, and microtubule dynamics in cells and calcium activity in nematode embryos.This work was supported by the Intramural Research Program of the National Institute of Biomedical Imaging and Bioengineering at the National Institutes of Health. P.L. and H.S. acknowledge summer support from the Marine Biological Laboratory at Woods Hole, through the Whitman- and Fellows- program. P.L. acknowledges support from NIH National Institute of Biomedical Imaging and Bioengineering (NIBIB) of the National Institutes of Health (NIH) under grant number R01EB017293. C.S. acknowledges funding from the National Institute of General Medical Sciences of NIH under Award Number R25GM109439 (Project Title: University of Chicago Initiative for Maximizing Student Development [IMSD]) and NIBIB under grant number T32 EB002103. Partial funding for the computation in this work was provided by NIH grant numbers S10 RRO21039 and P30 CA14599. A.U. and I.R.-S. were supported by the NSF grant number 1607645

Obesity and clinical outcomes in COVID-19 patients without comorbidities, a post-hoc analysis from ORCHID trial

ObjectiveLarge body of studies described individuals with obesity experiencing a worse prognosis in COVID-19. However, the effects of obesity on the prognosis of COVID-19 in patients without comorbidities have not been studied. Therefore, the current study aimed to provide evidence of the relationship between obesity and clinical outcomes in COVID-19 patients without comorbidities.MethodsA total of 116 hospitalized COVID-19 patients without comorbidities from the ORCHID study (Patients with COVID-19 from the Outcomes Related to COVID-19 Treated with Hydroxychloroquine among Inpatients with Symptomatic Disease) were included. Obesity is defined as a BMI of ≥30 kg/m2. A Cox regression analysis was used to estimate the hazard ratio (HR) for discharge and death after 28 days.ResultsThe percentage of obesity in COVID-19 patients without comorbidities was 54.3% (63/116). Discharge at 28 days occurred in 56/63 (84.2%) obese and 51/53 (92.2%) non-obese COVID-19 patients without comorbidities. Four (3.4%) COVID-19 patients without any comorbidities died within 28 days, among whom 2/63 (3.2%) were obese and 2/53 (3.8%) were non-obese. Multivariate Cox regression analyses showed that obesity was independently associated with a decreased rate of 28-day discharge (adjusted HR: 0.55, 95% CI: 0.35–0.83) but was not significantly associated with 28-day death (adjusted HR: 0.94, 95% CI: 0.18–7.06) in COVID-19 patients without any comorbidities.ConclusionsObesity was independently linked to prolonged hospital length of stay in COVID-19 without any comorbidity. Larger prospective trials are required to assess the role of obesity in COVID-19 related deaths

Single molecule study on protein dynamics by fluorescence confocal microscopy

Single molecule fluorescence spectroscopy provides a powerful tool to investigate molecular structural change and dynamics of heterogeneous biological system. This thesis work presents several projects involving experimental exploration and theoretical treatment based on statistical analysis. In single molecule optical research, two major challenges have to be overcome to obtain more reliable and meaningful information. One is the immobilization of singe molecules and the other is the analysis of limited data from stochastic single molecule signals. In this thesis, sol-gel encapsulation and trehalose immobilization have been explored and discussed, and they showed great promise to serve as good immobilization matrix. In another project, rotational dynamics of single Zinc Cytochrome C and single Porphyrin Cytochrome C were studied by two-channel polarization confocal microscopy. The results showed that proteins like Cytochrome C sensed very heterogeneous local environment within trehalose matrix and some of them actually were undergoing slow rotational motions. In the work of fluorescence lifetime distribution undergoing Förster energy transfer, single molecule technology was demonstrated to be very useful to solve inverse Laplace transform problem in a direct way. In the work of single CaM:peptide complexes, the distribution of fluorescence lifetime of probing dye, Nile Red, showed significant dependence of the calcium ion concentration, and the PAT analysis showed structural fluctuation of milli-second time scale at the mid-point of calcium ion titration curve. These results help to understand structural dynamics of CaM:peptide complex