Specimens of skin, skeletal muscle, adipose tissue, brain, peripheral nerve and catilage were taken from 6 cadavers (divided into 2 groups) perfused and embalmed with formalin. 90 pieces of the above-mentioned tissues were taken in different times and the paraffin sections were stained by routine HE. Electron microscopic observation was made from some skin and skeletal muscle specimens, and histochemical methods were used to demonstrate DNA, RNA, keratin(-SH, -SS), fatty acids and calcium in some skin materials. Loyez stain method for myelin sheath was applied to some brain and nerve sections.1. Skin tissue: In both group A and B, 83.3% and 78.9% of skin materials were appraised as grade I and II (excellent and good) respectively. The morphological changes appeared mainly as karyopyknosis of the epidermal cells and shrinkage of the secretory part of the sweat glands. Most of the skin tissues of the corpses perfused 3～4 hrs after death were well preserved, only 8.3% being in grade Ⅲ (moderate). On the other hand, 43% of skin materials taken from those perfused 30 hrs after death were in grade Ⅲ. Ultrastructurally, the shape of the epidermal cells and their adhensions still remained intact, but karyopyknosis or chromolysis and autolysis of most of the cytoplasmic membraneous structures were found. In those cadavers preserved for less than one year, there was no evidence of progressive changes in microscopic and submicroscopic structures of the skin. The tonofillaments and desmosomes were still kept well in those specimens preserved for many years, and their presence may be the cause of maintaining cell integrity. Histochemically, mercapto-reaction of keratin was kept stable and found to be well shown even in old samples of skin, but the disulfide reaction usually showed marked fading with time, probably due to exofolition of the stratum corneum. However, this reaction was well shown in the hairs and not weakened for many years.2. Fat tissue: Hydrolysis of lipid substances of subcutancous fat and sebaceous gland, as shown by the presence of fatty acid, was found in the corpses preserved even as short as half a year.3. Skeletal muscle: The preservation state of the skeletal muscle was also dependent on the complete perfusion in time. The structure of the muscle fibers was generally worse preserved than that of the skin as shown in severe myolysis. Since stagnation of the small blood vessels frequently accompanied myolysis, obstruction of microcirculation which prevented the permeation of fomalin into the muscle tissues may be the cause of rapid myolysis. The ultrastructural changes of the muscle fibers were the same as those of the epidermal cells. In all specimens even as old as 30 years, two types of myofillaments were well preserved, and bands could be seen distinctly.4. Nervous tissue: The brain tissues were well preserved in those corpses that were perfused shortly after death, but the peripheral nerves usually showed severe autolysis, obviously it is due to the same reasons as those for myolysis.5. Cartilage: The structural changes of cartilage after death were slow and all specimens of cartilage were well preserved.

Objective:To compare the social support levels as understood by family doctor team members in township hospitals/community health centers, and village clinics/community clinics, and their influencing factors, in order to provide reference for improving the work status of family doctor team members and enhancing the quality of family doctors′ contracted services.Methods:A multi-stage random cluster sampling method was used to sample medical workers from contracted family doctor teams in township hospitals/community health centers and their subordinate village clinics/community clinics in 6 counties (cities, districts) of Tai′an city, Shandong province. In August 2020, a questionnaire survey was conducted on the perceived level of social support among family doctor team members using the perceived social support scale. Descriptive analysis was conducted on the data, and independent sample t-tests and one-way ANOVA were used to conduct univariate analysis on the influencing factors of perceived social support scores of family doctor team members at different levels, while multiple linear regression analysis was used to conduct multivariate analysis. Results:A total of 765 valid questionnaires were collected, with 203 and 562 from township hospitals/community health centers and village clinics/community clinics, respectively. The total perceived social support scores of family doctor team members in township hospitals/community health centers and village clinics/community clinics were (65.56±10.29) and (67.31±10.14), respectively, featuring statistically significant differences ( t=-2.11, P<0.05). In-mirage marital status ( β=0.18, P=0.008), good/very good self-rated health status ( β= 0.25, P=0.048), participation of work-related training within one year ( β=0.17, P=0.010), relatively satisfied/very satisfied for job promotion ( β= 0.17, P=0.046), as well as above/far above average self-rated economic status as ( β=-0.15, P=0.027), were the influencing factor on the perceived social support scores of family doctor team members in township hospitals/community health centers. In-marriage marital status ( β= 0.12, P=0.002), good/very good self-rated health status ( β=0.14, P=0.026), junior or intermediate level or above professional title ( β=-0.11, P=0.003; β=-0.10, P=0.006), participation of work-related training within one year ( β= 0.14, P<0.001), and relatively satisfied/very satisfied for job promotion ( β= 0.16, P<0.001) were the influencing factors on the perceived social support scores of family doctor team members in village clinics/community clinics. Conclusions:Members of the family doctor teams in primary medical institutions in Tai′an city had a higher level of understanding of social support. There were differences in the social support levels of family doctor team members between the two levels of primary medical and health care institutions, and the influencing factors were not completely consistent. Targeted measures should be taken based on specific circumstances to enable them to better receive and perceive support from family and friends, and to improve the quality of family doctors′ contracted services.

Building a strong public health system has become an urgent task in the new era. Based on more than eight years of systematic research， we believe that five aspects need to be prioritized for a strong system. First， we should change the perspective on public health， using the word “gonggong jiankang” to replace “gonggong weisheng” and the word “gonggong jiankang tixi” to replace “gonggong weisheng tixi”， to lead the public health system development. Second， we should develop a suitable public health system and continuously improve the health capacity for governance. Third， we should make it clear that the goal of building a strong system is not far-fetched， and we need to consolidate the existing institutional advantages of China’s public health system： when encountering major problems， we can maintain a unified goal and mobilize the whole society to cooperate effectively to accomplish the goal. However， we need to make up for shortcomings one by one， especially to solve the key problem of lacking a strong coordination mechanism in daily work. Fourth， we should pursue excellence and consolidate the“suitable” mechanism proven in the process of coping with the COVID-19， so that efficient mechanisms to deal with major issues can be used in routine work， and efforts should be made to consolidate the advantages of prevention and control of infectious diseases and emergency response，so as to achieve the balanced development of regions categories and units.Finally， it is necessary to strengthen the coordination of government and research institutions， in the aspects of technological innovation， talent team building and accurate consulting services， and work together to pursue a suitable and strong system to realize the modernization of the health system and capacity for governance.

Alzheimer's disease (AD) is associated with the impairment of white matter (WM) tracts. The current study aimed to verify the utility of WM as the neuroimaging marker of AD with multisite diffusion tensor imaging datasets [321 patients with AD, 265 patients with mild cognitive impairment (MCI), 279 normal controls (NC)], a unified pipeline, and independent site cross-validation. Automated fiber quantification was used to extract diffusion profiles along tracts. Random-effects meta-analyses showed a reproducible degeneration pattern in which fractional anisotropy significantly decreased in the AD and MCI groups compared with NC. Machine learning models using tract-based features showed good generalizability among independent site cross-validation. The diffusion metrics of the altered regions and the AD probability predicted by the models were highly correlated with cognitive ability in the AD and MCI groups. We highlighted the reproducibility and generalizability of the degeneration pattern of WM tracts in AD.
Humans ; White Matter/diagnostic imaging* ; Diffusion Tensor Imaging/methods* ; Alzheimer Disease/complications* ; Reproducibility of Results ; Cognition ; Cognitive Dysfunction/complications* ; Brain/diagnostic imaging*