Cellulose nanocrystals obtained from natural sources are of great interest for many applications. In water, cellulose nanocrystals form a liquid crystalline phase whose hierarchical structure is retained in solid films after drying. Although tactoids, one of the most primitive components of liquid crystals, are thought to have a significant role in the evolution of this phase, they have evaded structural study of their internal organization. Here we report the capture of cellulose nanocrystal tactoids in a polymer matrix. This method allows us to visualize, for the first time, the arrangement of cellulose nanocrystals within individual tactoids by electron microscopy. Furthermore, we can follow the structural evolution of the liquid crystalline phase from tactoids to iridescent-layered films. Our insights into the early nucleation events of cellulose nanocrystals give important information about the growth of cholesteric liquid crystalline phases, especially for cellulose nanocrystals, and are crucial for preparing photonics-quality films.

Background and PurposeFatigue after stroke is common and has a negative impact on rehabilitation and survival. However, its pathogenesis and contributing factors remain unclear. The purpose of this study was to identify factors influencing the occurrence of fatigue after first-ever ischemic stroke in acute phase.MethodsWe examined 265 consecutive patients with first-ever ischemic stroke during acute phase (within 2 weeks) in two tertiary stroke care hospitals in Henan, China. We documented patients’ demographic and clinical characteristics through face-to-face interviews using structured questionnaires and reviews of medical records. Post-stroke fatigue was defined as a score of ≥4 using the Fatigue Severity Scale. Multivariate logistic regression was used to examine post-stroke fatigue in relation to socio-demographic, lifestyle, clinical characteristics and family function.ResultsAbout 40% first-ever ischemic stroke patients experienced post-stroke fatigue in acute phase. Post-stroke fatigue was associated with lack of exercise before stroke (adjusted odds ratio 4.01, 95% CI 1.95–8.24), family dysfunction (2.63, 1.20–5.80), depression (2.39, 1.02–5.58), the presence of pre-stroke fatigue (4.89, 2.13–11.21), use of sedative medications (4.14, 1.58–10.88), coronary heart disease (3.38, 1.46–7.79) and more severe Modified Rankin Scale (2.55, 1.65–3.95).ConclusionsThe causes of post-stroke fatigue are multifaceted. More physical exercise, improving family function, reducing depression and appropriate use of sedative medications may be helpful in preventing post-stroke fatigue.

BackgroundFamine provides quasi-experimental conditions for testing the hypothesis of “programming” health effects by poor nutrition in early life. It remains uncertain whether early life exposure to famine increases the risk of hypertension in adulthood. There is a lack of data on the relative impact of exposure to famine during fetal development versus infancy (<2 years postnatal). We sought to assess the impact of exposure to the 1959–1961 Chinese Great Famine (the largest in human history) during fetal development and infancy on the risks of hypertension, short stature and obesity in adulthood.Methodology/Principal FindingsWe conducted a retrospective cohort study of 12,065 adults (46–53 years of age) born 1957–1964 in the Zhongshan and Nanhai municipalities of Guangdong province, China. Adjusting for socio-demographic and lifestyle characteristics, as compared to subjects who were unexposed to famine, the risk of hypertension was not significantly elevated in subjects exposed to famine during fetal development only overall, but was 1.36-fold higher in those exposed during the first trimester of pregnancy only [adjusted odds ratio (OR) 1.36 (95% confidence intervals 1.03–1.79)], 1.83-fold higher in those exposed during infancy only [adjusted OR 1.83 (1.61–2.08)], and 1.31-fold higher in those exposed during both fetal development and infancy [adjusted OR 1.31 (1.14–1.51)]. Exposure to famine during infancy increased the risk of short stature. Early life exposure to famine did not increase the risk of obesity.Conclusions/SignificanceExposure to the Chinese Great Famine during the first trimester of pregnancy only, or during infancy only, or during both fetal development and infancy increased the risk of hypertension in adulthood, suggesting an important role of changes in exposure to famine during fetal development and from prenatal to early postnatal life in developmental “programming” cardiovascular disease risk.

Early neurological deterioration (END) is associated with increased risk of functional disability and mortality. However, data are limited regarding the long-term risk of poor functional outcomes. Thus we explored the association between END and long-term outcomes in patients with acute ischemic stroke.A total of 1064 patients were enrolled with acute ischemic stroke who were consecutively admitted to the 3 stroke units of Huai-He Hospital, Kaifeng, China. END was defined as an increment change of at least one point in motor power or total National Institute of Health Stroke Scale (NIHSS) score deterioration ≥2 points within the first week after admission. We retrospectively assessed the risk factors of END and prospectively explored the relationship between END and the long-term outcomes by multivariable regression models after adjusting the potential confounding factors. Outcomes were evaluated at 18 months based on modified Rankin scale (MRS) scores.Approximately 32% of first-ever ischemic stroke patients experienced END during the acute phase. END was associated with diabetes (odds ratio [OR], 2.218; 95% confidence interval [CI] 1.619–3.037), NIHSS score at admission (OR, 1.052; 95% CI 1.023–1.082), C-reactive protein (CRP) levels (OR, 1.224; 95% CI 1.066–1.406]), and homocysteine (HCY) levels (OR, 1.203; 95% CI 1.061–1.365) after adjusting related factors, such as hypertension, diabetes, NIHSS at admission, and some blood laboratory values, including direct bilirubin, total cholesterol, low-density lipoprotein, glucose, CRP, HCY, and D-dimer levels. During the follow-up period, 52 (4.9%) patients died, 160 (15.0%) recrudesced, and 317 (29.8%) suffered poor outcomes. Multivariate logistic regression analyses revealed that poor outcome was associated with END (OR, 3.366; 95% CI 2.495–4.542), age (OR, 1.028; 95% CI 1.015–1.041), body mass index (OR, 1.096; 95% CI 1.051–1.144), coronary heart disease (OR, 1.637; 95% CI 1.108–2.416), and CRP (OR, 2.474; 95% CI 1.840–3.326).The risk factors of END are multifaceted. Diabetes, NIHSS score at admission, CRP, and HCY are independent predictors of END. In addition, the results of this study indicate that END is an important predictor of poor functional outcome.

Objective: To explore the impact of workplace violence on job performance and quality of life of community healthcare workers in China, especially the relationship of these three variables. Methods: From December 2013 to April 2014, a total of 1404 healthcare workers were recruited by using the random cluster sampling method from Community Health Centers in Guangzhou and Shenzhen. The workplace violence scale, the job performance scale and the quality of life scale (SF-36) were self-administered. The structural equation model constructed by Amos 17.0 was employed to assess the relationship among these variables. Results: Our study found that 51.64% of the respondents had an experience of workplace violence. It was found that both job performance and quality of life had a negative correlation with workplace violence. A positive association was identified between job performance and quality of life. The path analysis showed the total effect (β = −0.243) of workplace violence on job performance consisted of a direct effect (β = −0.113) and an indirect effect (β = −0.130), which was mediated by quality of life. Conclusions: Workplace violence among community healthcare workers is prevalent in China. The workplace violence had negative effects on the job performance and quality of life of CHCs’ workers. The study suggests that improvement in the quality of life may lead to an effective reduction of the damages in job performance caused by workplace violence.

Tactoids are liquid crystalline microdroplets that spontaneously nucleate from isotropic dispersions, and transform into macroscopic anisotropic phases. These intermediate structures have been found in a range of molecular, polymeric and colloidal liquid crystals. Typically only studied by polarized optical microscopy, these ordered but easily deformable microdroplets are now emerging as interesting components for structural investigations and developing new materials. In this review, we highlight the structure, property and transformation of tactoids in different compositions, but especially cellulose nanocrystals. We have selected references that illustrate the diversity and most exciting developments in tactoid research, while capturing the historical development of this field.This article is part of a discussion meeting issue 'New horizons for cellulose nanotechnology'.

Diffraction gratings are important for modern optical components, such as optical multiplexers and signal processors. Although liquid crystal (LC) gratings based on thermotropic LCs have been extensively explored, they often require expensive molecules and complicated manufacturing processes. Lyotropic LCs, which can be broadly obtained from both synthetic and natural sources, have not yet been applied in optical gratings. Herein, a facile grating fabrication method using a biosourced lyotropic LC formed by cellulose nanocrystals (CNCs), a material extracted from plants, is reported. Hydrogel sheets with vertically aligned uniform periodic structures are obtained by fixing the highly oriented chiral nematic LC of CNCs in polymer networks under the cooperative effects of gravity on phase separation and a magnetic field on LC orientation. The hydrogel generates up to sixth‐order diffraction spots and shows linear polarization selectivity, with tunable grating periodicity controlled through LC concentration regulation. This synthesis strategy can be broadly applied to various grating materials and opens up a new area of optical materials from lyotropic LCs.

Polymer microspheres with chiral nematic order were obtained from an emulsion polymerization technique using cellulose nanocrystals (CNCs) as the template. The growth of the liquid crystals from tiny tactoids to droplets with spherical symmetry was captured and investigated by both optical and electron microscopy for the first time. The size of the microspheres could be tuned between tens and hundreds of micrometers; to obtain single, integrated chiral nematic kernels, the size of water droplets in the emulsion should be similar to that of CNC tactoids. Through a double-matrix templating method, novel silica microspheres with chiral nematic order were fabricated, which showed a high surface area and mesoporosity. The methods developed here may help to reveal the evolution of other self-assembling systems, and these materials have potential applications in optical devices and chiral separations.