The Chain Flexibility Effects on the Self-assembly of Diblock Copolymer in Thin Film

We investigate the effects of chain flexibility on the self-assembly behavior of symmetric diblock copolymers (BCPs) when they are confined as a thin film between two surfaces. Employing worm-like chain (WLC) self-consistent field theory, we study the relative stability of parallel (L$_{\parallel}$) and perpendicular (L$_{\perp}$) orientations of BCP lamellar phases, ranging in chain flexibility from flexible Gaussian chains to semi-flexible and rigid chains. For flat and neutral bounding surfaces (no surface preference for one of the two BCP components), the stability of the L$_{\perp}$ lamellae increases with chain rigidity. When the top surface is flat and the bottom substrate is corrugated, increasing the surface roughness enhances the stability of the L$_{\perp}$ lamellae for flexible Gaussian chains. However, an opposite behavior is observed for rigid chains, where the L$_{\perp}$ stability decreases as the substrate roughness increases. We further show that as the substrate roughness increases, the critical value of the substrate preference, $u^{*}$, corresponding to an L$_{\perp}$-to-L$_{\parallel}$ transition, decreases for rigid chains, while it increases for flexible Gaussian chains. Our results highlight the physical mechanism of tailoring the orientation of lamellar phases in thin-film setups. This is of importance, in particular, for short (semi-flexible or rigid) chains that are in high demand in emerging nanolithography and other industrial applications

Adopting Strategic Niche Management to Evaluate EV Demonstration Projects in China

Electric Vehicles (EVs) are considered to be a potential viable technology to address the persistent unsustainable problems in transport sector. In this paper, we focus on analyzing the transition processes of EVs in China because the sustainability of developing countries is essential for the worldwide sustainability. The two-round demonstration programs of EVs in China were analyzed by adopting the strategic niche management (SNM) approach so as to find out what niche protection has been provided and which obstacles hamper the further development of EVs. The results show that the financial subsidy is the most important protective measure. However, the diffusion results of EVs in different pilot cities are greatly different. The main reason lies in the uneven geographical landscape. In addition, some obstacles were exposed during the niche internal processes including low quality of expectations and poor alignment within the network. Based on the analysis results, we develop a list of suggestions that are important to consider when developing EVs

Application, knowledge and training needs regarding comprehensive geriatric assessment among geriatric practitioners in healthcare institutions: a cross-sectional study

Abstract Background This study aimed to investigate the actual application, knowledge, and training needs of comprehensive geriatric assessment (CGA) among geriatric practitioners in China. Methods A total of 225 geriatric practitioners attending the geriatric medicine or geriatric nursing training were recruited for this cross-sectional study. The questionnaire included demographics, healthcare institution characteristics, the actual application, knowledge, training needs, and barriers to CGA and geriatric syndromes (GS). Results Physicians and nurses were 57.3% and 42.7%, respectively. 71.1% were female, with a median age was 35 years. Almost two-thirds (140/225) of geriatric practitioners reported exposure to CGA in their clinical practice. The top five CGA evaluation items currently used were malnutrition risk (49.8%), fall risk (49.8%), activity of daily living (48.0%), pain (44.4%), and cognitive function (42.7%). Median knowledge scores for the management procedures of GS ranged from 2 to 6. Physicians identified medical insurance payment issues (29.5%) and a lack of systematic specialist knowledge and technology (21.7%) as the two biggest barriers to practicing geriatrics. Nurses cited a lack of systematic specialist knowledge and technology (52.1%) as the primary barrier. In addition, physicians and nurses exhibited significant differences in their knowledge of CGA-specific evaluation items and management procedures for GS (all P < 0.05). However, there were no significant differences in their training needs, except for polypharmacy. Conclusions The rate of CGA application at the individual level, as well as the overall knowledge among geriatric practitioners, was not adequate. Geriatric education and continuous training should be tailored to address the specific roles of physicians and nurses, as well as the practical knowledge reserves, barriers, and training needs they face

NUMERICAL INVESTIGATIONS ON THE EFFECTS OF SEABED SHALLOW SOILS ON A TYPICAL DEEPWATER SUBSEA WELLHEAD SYSTEM

Deepwater subsea wellheads may be significantly threatened under extreme sea conditions and operations, especially when the seabed is composed of very soft clay properties. A numerical model of a deepwater wellhead system is established using the classic ocean pipe element and nonlinear spring element of ANSYS to examine the behaviors of subsea wellheads in diverse seabed soil. Nonlinear spring elements coded in the APDL language are used to model three types of seabed soils: very soft soil, soft soil, and firm soil. The dynamic and quasi-static behaviors of the wellhead system in the typical coupled and decoupled models of the drilling riser system are particularly investigated in depth. The effects of the nonlinear seabed soil properties on the detailed wellhead are realistically simulated using time domain and extremum analysis. The results show that the softer the seabed soil, the greater the displacement, rotation angle, curvature, and bending moment of deepwater subsea wellheads. When the seabed soil reaches a particular depth, the mechanical characteristics of the wellheads under the three types of seabed soil conditions are almost simultaneously close to zero. Overall, several conclusions reached in this study may provide some useful references for design and stability analysis

Induced dopaminergic neurons: A new promise for Parkinson’s disease

Motor symptoms that define Parkinson’s disease (PD) are caused by the selective loss of nigral dopaminergic (DA) neurons. Cell replacement therapy for PD has been focused on midbrain DA neurons derived from human fetal mesencephalic tissue, human embryonic stem cells (hESC) or human induced pluripotent stem cells (iPSC). Recent development in the direct conversion of human fibroblasts to induced dopaminergic (iDA) neurons offers new opportunities for transplantation study and disease modeling in PD. The iDA neurons are generated directly from human fibroblasts in a short period of time, bypassing lengthy differentiation process from human pluripotent stem cells and the concern for potentially tumorigenic mitotic cells. They exhibit functional dopaminergic neurotransmission and relieve locomotor symptoms in animal models of Parkinson’s disease. In this review, we will discuss this recent development and its implications to Parkinson’s disease research and therapy. Keywords: Parkinson’s disease, Induced dopaminergic neuron, Induced neuron, Induced pluripotent stem cell, Transcription facto

Ru coordinated with BINAP in knitting aryl network polymers for heterogeneous asymmetric hydrogenation of methyl acetoacetate

A facile method for the preparation of heterogeneous asymmetric hydrogenation catalysts was presented. BINAP was knitted with aryl compounds using formaldehyde dimethyl acetal (FDA) as a crosslinker by Friedel-Crafts reaction without any pre-modification. The prepared catalysts showed different catalytic activities, and excellent recyclablilty results could be achieved in asymmetric hydrogenation

Valorization of Fish Processing By-Products: Microstructural, Rheological, Functional, and Properties of Silver Carp Skin Type I Collagen

The objective of this study was to develop aquatic collagen production from fish processing by-product skin as a possible alternative to terrestrial sources. Silver carp skin collagen (SCSC) was isolated and identified as type I collagen, and LC-MS/MS analysis confirmed the SCSC as Hypophthalmichthys molitrix type I collagen, where the yield of SCSC was 40.35 &plusmn; 0.63% (dry basis weight). The thermal denaturation temperature (Td) value of SCSC was 30.37 &deg;C, which was superior to the collagen of deep-sea fish and freshwater fish. Notably, SCSC had higher thermal stability than human placental collagen, and the rheological experiments showed that the SCSC was a shear-thinning pseudoplastic fluid. Moreover, SCSC was functionally superior to some other collagens from terrestrial sources, such as sheep, chicken cartilage, and pig skin collagen. Additionally, SCSC could provide a suitable environment for MC3T3-E1 cell growth and maintain normal cellular morphology. These results indicated that SCSC could be used for further applications in food, cosmetics, and biomedical fields