生态环境政策的政府注意力演变与启示——基于1978—2022年中央政府工作报告的语义网络分析

生态环境是经济可持续发展的重要支撑,而生态环境政策是推动生态环境有效保护的系统指引和制度保障。以1978—2022年的44篇这中央政府工作报告为样本,基于语义网络分析法对不同阶段的生态环境政策文本的内容和关联词进行梳理,揭示出生态环境政策的政府注意力演变规律和特点,最后根据研究结论提出完善生态环境政策的建议,进一步促进生态环境政策发挥效能。

Heterozygous lipoprotein lipase knockout mice exhibit impaired hematopoietic stem/progenitor cell compartment

Background : Hematopoietic stem cells (HSC) maintain the hematopoietic system homeostasis through self- renewal and multilineage differentiation potential. HSC are regulated by the microenvironment, cytokine signaling, and transcription factors. Recent results have shown that lipid pathways play a key role in the regulation of HSC quiescence, proliferation, and division. However, the mechanism by which lipid metabolism regulates HSC proliferation and differentiation remains to be clarified. Lipoprotein lipase (LPL) is an essential enzyme in the anabolism and catabolism of very low- density lipoprotein, chylomicrons, and triglyceride- rich lipoproteins. Methods : The percentage of hematopoietic stem/progenitor cells and immune cells were determined by fluorescence- activated cell sorting (FACS). The function and the mechanism of HSCs were analyzed by cell colony forming assay and qPCR analysis. The changes in LPL^(+/−) HSC microenvironment were detected by transplantation as- says using red fluorescent protein (RFP) transgenic mice. Results : To explore the function of LPL in HSC regulation, heterozygous LPL- knockout mice (LPL^(+/−)) were established and analyzed by FACS. LPL^(+/−) mice displayed decreased hematopoietic stem/progenitor cell compartments. In vitro single- cell clono- genic assays and cell-cycle assays using FACS promoted the cell cycle and increased proliferation ability. qPCR analysis showed the expression of p57^(KIP2) and p21^(WAF1)/ ^(CIP1) in LPL^(+/−) mice was upregulated. Conclusions : LPL^(+/−) mice exhibited HSC compartment impairment due to promotion of HSC proliferation, without any effects on the bone marrow (BM) microenvironment.

Transplantation of bone marrow mesenchymal stem cells improves cognitive deficits and alleviates neuropathology in animal models of Alzheimer’s disease: a meta-analytic review on potential mechanisms

Background Alzheimer’s disease is a neurodegenerative disorder.Therapeutically,a transplantation of bone marrow mesenchymal stem cells(BMMSCs)can play a beneficial role in animal models of Alzheimer’s disease.However,the relevant mechanism remains to be fully elucidated.Main body Subsequent to the transplantation of BMMSCs,memory loss and cognitive impairment were significantly improved in animal models with Alzheimer’s disease(AD).Potential mechanisms involved neurogenesis,apoptosis,angiogenesis,inflammation,immunomodulation,etc.The above mechanisms might play different roles at certain stages.It was revealed that the transplantation of BMMSCs could alter some gene levels.Moreover,the differential expression of representative genes was responsible for neuropathological phenotypes in Alzheimer’s disease,which could be used to construct gene-specific patterns.Conclusions Multiple signal pathways involve therapeutic mechanisms by which the transplantation of BMMSCs improves cognitive and behavioral deficits in AD models.Gene expression profile can be utilized to establish statistical regression model for the evaluation of therapeutic effect.The transplantation of autologous BMMSCs maybe a prospective therapy for patients with Alzheimer’s disease.

Effectiveness and mechanisms of adiposederived stem cell therapy in animal models of Parkinson’s disease:a systematic review and meta-analysis

Animal models provide an opportunity to assess the optimal treatment way and the underlying mechanisms of direct clinical application of adipose-derived stem cells(ADSCs).Previous studies have evaluated the effects of primitive and induced ADSCs in animal models of Parkinson’s disease(PD).Here,eight databases were systematically searched for studies on the effects and in vivo changes caused by ADSC intervention.Quality assessment was conducted using a 10-item risk of bias tool.For the subsequent meta-analysis,study characteristics were extracted and effect sizes were computed.Ten out of 2324 published articles(n=169 animals)were selected for further meta-analysis.After ADSC therapy,the rotation behavior(10 experiments,n=156 animals)and rotarod performance(3 experiments,n=54 animals)were improved(P<0.00001 and P=0.0003,respectively).The rotation behavior test reflected functional recovery,which may be due to the neurogenesis from neuronally differentiated ADSCs,resulting in a higher pooled effect size of standard mean difference(SMD)(−2.59;95%CI,−3.57 to−1.61)when compared to that of primitive cells(−2.18;95%CI,−3.29 to−1.07).Stratified analyses by different time intervals indicated that ADSC intervention exhibited a long-term effect.Following the transplantation of ADSCs,tyrosine hydroxylase-positive neurons recovered in the lesion area with pooled SMD of 13.36[6.85,19.86].Transplantation of ADSCs is a therapeutic option that shows long-lasting effects in animal models of PD.The potential mechanisms of ADSCs involve neurogenesis and neuroprotective effects.The standardized induction of neural form of transplanted ADSCs can lead to a future application in clinical practice.