Cadherin-18 loss in prospermatogonia and spermatogonial stem cells enhances cell adhesion through a compensatory mechanism

Extracellular membrane proteins are crucial for mediating cell attachment,recognition,and signal transduction in the testicular microenvironment,particularly germline stem cells.Cadherin 18(CDH18),a type Ⅱ classical cadherin,is primarily expressed in the nervous and reproductive systems.Here,we investigated the expression of CDH18in neonatal porcine prospermatogonia(ProSGs)and murine spermatogonial stem cells(SSCs).Disruption of CDH18 expression did not adversely affect cell morphology,proliferation,self-renewal,or differentiation in cultured porcine ProSGs,but enhanced cell adhesion and prolonged cell maintenance.Transcriptomic analysis indicated that the down-regulation of CDH18 in ProSGs significantly up-regulated genes and signaling pathways associated with cell adhesion.To further elucidate the function of CDH18 in germ cells,Cdh18 knockout mice were generated,which exhibited normal testicular morphology,histology,andspermatogenesis.Transcriptomic analysis showed increased expression of genes associated with adhesion,consistent with the observations in porcine ProSGs.The interaction of CDH18withβ-catenin and JAK2 in both porcine ProSGs and murine SSCs suggested an inhibitory effect on the canonical Wnt and JAK-STAT signaling pathways during CDH18 deficiency.Collectively,these findings highlight the crucial role of CDH18 in regulating cell adhesion in porcine ProSGs and mouse SSCs.Understanding this regulatory mechanism provides significant insights into the testicular niche.

An approach to the influence of industrial structure on urban ecological environment

dustrial structure is key link of man's action to ecological environmental system. Its combina-tion type and intensity determine, to a great extent, economic benefit, resources utilization efficiency andstress on environment. So the assessment to the rationality of industrial structure is of great importance. Inpresent paper, the research theories and ways on relationship between industrial structure and ecological en-vironmental systems were put forward. Environmental carrying capacity (ECC) was adopted to describequantitatively the relationship between man's social economic activity and environmental resources. At theend of this paper. analysis was made with Benxi City as an example.

Synthesis of chiral dihydrofuran compounds by thiourea derivatives-catalyzed“interrupted”Feist-Bénary reaction

In this study,six thiourea derivatives of cinchona alkaloids with 9-nat or 9-epi-configuration were synthesized.After characterized the structures,we adopted them to the asymmetric'interrupted'Feist-Benary(IFB) reaction ofα-haloketones withβ-dicarbonyl compounds,to give optically active dihydrofurans.Various thiourea derivatives as organocatalysts were examined.The corresponding chiral hydroxyl dihydrofurans have been obtained in excellent yields and moderate ees.To the acyclic substrate,we obtained excitin...

有机化学全线上BOPPPS教学模式实践

面对疫情背景下"完全线上教学"的现状,聚焦线上教学互动设计及高质量教学效果达成,我们在四年制药学专业有机化学教学中,基于超星学习通和QQ直播,将BOPPPS教学模式从课堂延伸到课前、课后的学习活动中,形成了具有一定特色的全线上有机化学BOPPPS教学模式,实现了在线教学的有效互动,取得了良好的教学效果。该线上教学方案为后续线上课程教学改革和打造有机化学"金课"奠定了基础。

Ultrasound features of primary non-Hodgkin’s lymphoma of the palatine tonsil:A case report

BACKGROUND Lymphomas are the second most common malignancy of the head and neck.In this region,the vast majority of extranodal lymphomas are located in the palatine tonsil,accounting for about 51%.Tonsillar lymphomas are aggressive tumors with intermediate-or high-grade histology.We here report a case of primary non-Hodgkin’s lymphoma of the palatine tonsil and analyze its ultrasound features.CASE SUMMARY A 40-year-old man presented with right palatine tonsil swelling for 2 mo after a cold,accompanied by dysphagia,snoring,and suffocation.He had no sore throat,fever,or history of upper respiratory tract infection or tuberculosis.The patient was generally in good health and denied other diseases.He was diagnosed with acute tonsillitis initially and treated with antibiotics for 7 d.However,there was no improvement with the treatment.Tonsil biopsy and ultrasound-guided biopsy of the biggest lymph node of the right neck showed the typical pathology of non-Hodgkin lymphoma.CONCLUSION Primary lymphoma of the tonsils is rare,and its diagnosis is challenging.Ul-trasound is a useful modality in diagnosing oropharyngeal diseases,and can clearly show the features of this tumor,but the final diagnosis should be estab-lished by histology.

Analysis of relationship between economic growth and environment in Benxi Shiqiaozi Development Zone

How to express and assess the coordination between environmental system and economic system is one crucial problem for the studies on regional sustainable development.The present study applies environmental supporting capacity (ESC) to evaluate the comparative coordination of economic development plans in a case study in Shiqiaozi Development Zone.The analysis conclusion showed the method is practicable.A new method for judging the efficiency of utilization of environmental system is also discussed in this paper.

铱催化串联不对称烯丙基取代/双键异构化构建轴手性化合物

轴手性化合物是一类重要的手性化合物,其中苯乙烯类轴手性化合物因其轴手性稳定性相对较差,目前高效不对称合成的方法比较局限.本工作以β-萘酚作为亲核试剂,通过将金属铱催化不对称烯丙基取代与双键异构化串联,实现了中心手性到轴手性的转移,从而高效地合成了一系列β-萘酚衍生的苯乙烯类轴手性化合物.

铱催化Z式保留不对称烯丙基取代反应

Z-烯烃是有机分子的基本结构单元,但是Z-烯烃相对于E-烯烃热力学不稳定,导致其高选择性合成极具挑战性.含有Z-烯烃的手性结构单元广泛地存在于天然产物和生物活性分子中,发展其高效精准合成方法具有十分重要的意义.过渡金属催化不对称烯丙基取代反应可以便捷地合成含有E-烯烃或者末端烯烃的手性分子,但是利用该类反应高选择性地得到含有Z-烯烃的手性分子十分困难[1~3].

手性催化与合成中的一些凝聚态化学问题

凝聚态化学作为一门研究化学反应中凝聚态物质的科学,最近引起了化学界的广泛关注。从手性化学角度出发,本文列举了近年来手性催化与合成中的一些凝聚态化学现象,分类介绍了不对称催化反应中不同类型的凝聚态物质,并通过列举实例分析讨论了凝聚态物质的具体组成、层次结构等因素对反应的催化活性、对映及区域选择性控制影响,以望能引起业界对凝聚态科学的关注,启发更多学者从凝聚态化学角度思考有机化学反应本质并解决相关问题,完善凝聚态科学体系。