Biocompatible polymers with tunable mechanical properties and conductive functionality on two-photon 3D printing.

Two-photon polymerization (TPP)-based 3D printing technology utilizes the two-photon absorption process of near-infrared radiation, enabling the fabrication of micro- and nano-scale three-dimensional structures with extremely high resolution. It has been widely applied in scientific fields closely related to living organisms, such as tissue engineering, drug delivery, and biosensors. Nevertheless, the existing photoresist materials have poor mechanical tunability and are hardly able to be doped with functional materials, resulting in constraints on the preparation of functional devices with micro-nano structures. In this paper, TPP printable polymer formulas with good mechanical tunability, high resolution, strong functional scalability, and excellent biocompatibility are proposed, by using the synergistic effects of a hydroxyl group-containing photocurable resin prepolymer, UV acrylate monomer, long-chain hydrophilic crosslinking monomer and photo-initiator. This can ensure the printability and help to improve the flexibility of the printed polymer, thereby solving the problem the photosensitive materials suitable for two-photon 3D printing in previous research had in balancing the formability and flexibility. The results of nanoindenter analysis showed that the Young's modulus of the printed structure can be adjusted between 0.3 GPa and 1.43 GPa, realizing mechanical tunability. Also, complex structures, such as micro-scaffold structures and high aspect ratio hollow microneedles were printed to explore the structural stability as well as the feasibility of biodevice application. Meanwhile, the proposed polymer formula can be functionalized to be conductive by doping with functional nanomaterial MXene. Finally, the biocompatibility of the proposed polymer formula was studied by culturing with human normal lung epithelial cells. The results indicated a good potential for biodevice applications.

Fabrication of Energetic Composites with 91% Solid Content by 3D Direct Writing.

Direct writing is a rapidly developing manufacturing technology that is convenient, adaptable and automated. It has been used in energetic composites to manufacture complex structures, improve product safety, and reduce waste. This work is aimed at probing the formability properties and combustion performances of aluminum/ammonium perchlorate with a high solid content for direct writing fabrication. Four kinds of samples with different solid content were successfully printed by adjusting printing parameters and inks formulas with excellent rheological behavior and combustion properties. A high solid content of 91% was manufactured and facile processed into complex structures. Micromorphology, rheology, density, burning rate, heat of combustion and combustion performance were evaluated to characterized four kinds of samples. As the solid content increases, the density, burning rate and heat of combustion are greatly enhanced. Based on 3D direct writing technology, complex energetic 3D structures with 91% solid content are shaped easier and more flexibly than in traditional manufacturing process, which provides a novel way for the manufacture of complicated structures of energetic components.

FLImBrush: dynamic visualization of intraoperative free-hand fiber-based fluorescence lifetime imaging.

A free-hand scanning approach to medical imaging allows for flexible, lightweight probes to image intricate anatomies for modalities such as fluorescence lifetime imaging (FLIm), optical coherence tomography (OCT) and ultrasound. While very promising, this approach faces several key challenges including tissue motion during imaging, varying lighting conditions in the surgical field, and sparse sampling of the tissue surface. These challenges limit the coregistration accuracy and interpretability of the acquired imaging data. Here we report FLImBrush as a robust method for the localization and visualization of intraoperative free-hand fiber optic fluorescence lifetime imaging (FLIm). FLImBrush builds upon an existing method while employing deep learning-based image segmentation, block-matching based motion correction, and interpolation-based visualization to address the aforementioned challenges. Current results demonstrate that FLImBrush can provide accurate localization of FLIm point-measurements while producing interpretable and complete visualizations of FLIm data acquired from a tissue surface. Each of the main processing steps was shown to be capable of real-time processing (> 30 frames per second), highlighting the feasibility of FLImBrush for intraoperative imaging and surgical guidance. Current findings show the feasibility of integrating FLImBrush into a range of surgical applications including cancer margins assessment during head and neck surgery.

Awareness Status of Chronic Disabling Neurological Diseases among Elderly Veterans.

BACKGROUND: The awareness, treatment and prevention of chronic diseases are generally poor among the elderly population of China, whereas the prevention and control of chronic diseases in elderly veteran communities have been ongoing for more than 30 years. Therefore, investigating the awareness status of chronic disabling neurological diseases (CDND) and common chronic diseases (CCD) among elderly veterans may provide references for related programs among the elderly in the general population. METHODS: A cross-sectional survey was conducted among veterans ≥60 years old in veteran communities in Beijing. The awareness of preventive strategies against dementia, Alzheimer's disease (AD), Parkinson's disease (PD), sleep disorders, cerebrovascular disease (CVD) and CCD such as hypertension, and the approaches used to access this information, including media, word of mouth (verbal communication among the elderly) and health care professionals, were investigated via face-to-face interviews. RESULTS: The awareness rates for CCD and CVD were approximately 100%, but that for AD was the lowest at <10%. The awareness rates for sleep disorders, PD and dementia, were 51.0-89.4%. Media was the most commonly selected mode of communication by which veterans acquired knowledge about CCD and CVD. Media was used by approximately 80% of veterans. Both health care professionals and word of mouth were used by approximately 50% of veterans. With respect to the source of information about CDND excluding AD, the rates of the use of health care professionals, word of mouth and media were 10.6-28.2%, 56.5-76.5%, and approximately 50%, respectively. CONCLUSIONS: The awareness of CDND among elderly veterans was significantly lower than that of CCD. More information about CDND should be disseminated by health care professionals. Appropriate guidance will promote the rapid and extensive dissemination of information about the prevention of CDND by media and word-of-mouth peer education.

[The contributing risk factors, prevention and treatment of functional dependence among the oldest-old and elderly subjects].

OBJECTIVE: To compare the risk factors on the functional dependence between the oldest-old and elderly veterans. METHODS: A cross-sectional survey was conducted among veterans ( ≥ 60 years of age) lived in 44 veterans' communities in Beijing. The socio-demographic information and history of non-communicable chronic diseases were collected via face-to-face interviews, and the functional status was assessed by the 20-item version of the Activities of Daily Living Scale. RESULTS: The risk factors associated with increased hazard of the functional dependence in the oldest-old ( ≥ 80 years old) were cognitive impairment, extrapyramidal diseases, cerebral infarction, transient ischemic attack, sleep disorders, hypnotics, osteoarthrosis, hypertension and fall with the odds ratio (OR) of 1.241-2.962 (all P < 0.05). Stroke, depression, cognitive impairment, extrapyramidal diseases, sleep disorders, hypnotics, fall, cardiovascular diseases, osteoarthrosis and hearing loss were the risk factors for that in the elderly subjects (aged 60-79 years). The OR was 1.232-5.790 (all P < 0.05). However, avocational activities such as social activity, physical exercise, photography, reading and games, decreased the risk of functional dependence in both the oldest-old and elderly people. CONCLUSIONS: Neuropsychiatric disorders are the leading causes contributed to the functional dependence among oldest-old and elderly population. Neurodegenerative diseases in the oldest-old, stroke and depression in elderly people should be the priorities in ameliorating disability. Healthy lifestyle and avocational activities could improve the functional status of the oldest-old and elderly population.