BACKGROUND:Socket-shield technique can effectively maintain labial soft and hard tissues,but the incidence of postoperative complications such as exposure and displacement of root shield is relatively high.It is speculated that the root shield may be exposed and displaced due to excessive load after long-term function of dental implants. OBJECTIVE:Through three-dimensional finite element analysis,we aim to study the influence of varying root shield thicknesses on the stress distribution,equivalent stress peaks,and displacement in the root shield,periodontal ligaments,implant,and surrounding alveolar bone under normal occlusal loading.We also attempt to analyze the correlation between the thickness of the root shield and occurrence of mechanical events such as root shield exposure,displacement,and fracture. METHODS:Cone-beam CT data of a patient who met the indication standard of socket-shield technique for maxillary central incisor were retrieved from database.Reverse engineering techniques were used to build models of the maxillary bone and root shield,while forward engineering was used to create models for the implant components based on their parameters.Models depicting various root shield thicknesses(0.5,1.0,1.5,and 2.0 mm)were created using Solidworks 2022 software.ANSYS Workbench 2021 software was then used to simulate and analyze the effects of varying root shield thicknesses on stress distribution,equivalent stress peaks,and displacement of the root shields,periodontal ligaments,implants,and surrounding alveolar bone under normal occlusion. RESULTS AND CONCLUSION:(1)In all root shield models,the stress was concentrated on the palatal cervical side,both sides of the edges and the lower edge of the labial side.As the thickness of the root shield increased,the equivalent stress peak and displacement showed a decreasing trend.The 0.5 mm thickness model produced a stress concentration of 176.20 MPa,which exceeded the yield strength(150 MPa)of tooth tissue.(2)The periodontal ligament stress in each group was concentrated in the neck margin and upper region.With the increase of root shield thickness,the equivalent stress peak and displacement of periodontal ligament showed a decreasing trend.(3)Implant stress in all models was concentrated in the neck of the implant and the joint of the implant-repair abutment,and the labial side was more concentrated than the palatal side.With the increase of root shield thickness,the equivalent stress peak of the implant in the model showed an increasing trend.(4)In each group of models,stress of cortical bone concentrated around the neck of the implant and the periphery of the root shield,and the labial side was more concentrated than the palatal side.With the increase of the thickness of the root shield,the equivalent stress peak around the root shield decreased;the peak value of the equivalent stress of the bone around the neck of the implant showed an increasing trend.In the model,the stress of cancellous bone was mainly concentrated around the neck of the lip of the implant,the top of the thread,the root tip and the lower margin of the root shield,and the labial side was more concentrated than the palatal side.With the increase of the thickness of the root shield,the peak value of the equivalent stress of the bone around the root shield in the model showed a decreasing trend.The minimum principal stress of cortical bone in each group of models was concentrated around the neck of the implant,exhibiting a fan-shaped distribution.As the thickness of the root shield increased,the minimum principal stress of cortical bone showed an increasing trend.(5)These results indicate that different thicknesses of the root shield have different biomechanical effects.The root shield with a thickness of 0.5 mm is easy to fracture.For patients with sufficient bone width,the root shield with a thickness of 2.0 mm is an option to reduce the risk of complications such as root shield exposure,fracture,and displacement.Meanwhile,it should be taken into account to protect the periodontal ligament in the preparation process,and rounding treatments ought to be carried out on both sides and the lower edge of the root shield.

In this paper, a preliminary stress/strain analysis of the design structure of a nickel-titanium alloy patent foramen ovale occluder is conducted with the finite element simulation analysis method. In the analysis, solid structure modeling is carried out on three different specifications of domestic patent foramen ovale occluders. Referring to the test method of fatigue performance in inspection standard YY/T 1553-2017, an initial installation deformation is applied to the model, and then the fatigue displacement of 2 mm is applied to the sample to make the model fatigue deformation. The fatigue safety factors of each type of occluder are obtained by strain simulation analysis. The results indicate that the minimum fatigue safety factors of the three specifications of domestic patent foramen ovale occluders are 2.09, 2.35 and 2.06 respectively, which all meet the design of fatigue safety factor greater than 1. Among them, 1818 and 3030 specifications of patent foramen ovale occluders have close values in minimum fatigue safety factors, and both are lower than that of 1825 model. Therefore, it is recommended to carry out physical fatigue tests on both 1818 and 3030 specifications to further verify the fatigue performance of the products.
Finite Element Analysis ; Titanium ; Nickel ; Alloys ; Foramen Ovale, Patent ; Materials Testing ; Septal Occluder Device ; Stress, Mechanical

Ischemic stroke (IS) is a globally life-threatening disease. Presently, few therapeutic medicines are available for treating IS, and rt-PA is the only drug approved by the US Food and Drug Administration (FDA) in the US. In fact, many agents showing excellent neuroprotection but no blood flow-improving activity in animals have not achieved ideal clinical efficacy, while thrombolytic drugs only improving blood flow without neuroprotection have limited their wider application. To address these challenges and meet the huge unmet clinical need, we have designed and identified a novel compound AAPB with dual effects of neuroprotection and cerebral blood flow improvement. AAPB significantly reduced cerebral infarction and neural function deficit in tMCAO rats, pMCAO rats, and IS rhesus monkeys, as well as displayed exceptional safety profiles and excellent pharmacokinetic properties in rats and dogs. AAPB has now entered phase I of clinical trials fighting IS in China.

Aralia taibaiensi, widely distributed in western China, particularly in the Qinba Mountains, has been utilized as a folk medicine for treating diabetes, gastropathy, rheumatism, and cardiovascular diseases. Saponins from A. taibaiensis (sAT) have demonstrated protective effects against oxidative stress and mitochondrial dysfunction induced by ischemia/reperfusion (I/R). However, the underlying mechanisms remain unclear. In vivo, middle cerebral artery occlusion/reperfusion (MCAO/R) induced inflammatory infiltration, neuronal injury, cell apoptosis, mitochondrial dysfunction, and oxidative stress in the ischaemic penumbra, which were effectively mitigated by sAT. sAT increased the mRNA and protein expression levels of apelin and its receptor apelin/apelin receptors (ARs) both in vivo and in vitro. (Ala13)-Apelin-13 (F13A) and small interfering RNA (siRNA) abolished the regulatory effects of sAT on neuroprotection mediated by adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK)/protein kinase B (Akt). Furthermore, sAT induced apelin/AR expression by simultaneously inhibiting P38 mitogen-activated protein kinase (P38 MAPK)/activating transcription factor 4 (ATF4) and upregulating hypoxia-inducible factor-1α (HIF-1α). Our findings indicate that sAT regulates apelin/AR/AMPK by inhibiting P38 MAPK/ATF4 and upregulating HIF-1a, thereby suppressing oxidative stress and mitochondrial dysfunction.
Animals ; Reperfusion Injury/prevention & control* ; Aralia/chemistry* ; Saponins/administration & dosage* ; AMP-Activated Protein Kinases/genetics* ; Male ; Apelin/genetics* ; Signal Transduction/drug effects* ; Neuroprotective Agents/administration & dosage* ; Brain Ischemia/genetics* ; Rats, Sprague-Dawley ; Rats ; Oxidative Stress/drug effects* ; Apelin Receptors/genetics* ; Humans ; Apoptosis/drug effects* ; Mice

Traditional Chinese medicine is an important part of Chinese traditional culture and has played an increasingly important role in the field of health care in recent years.Shandong Province,as a province with large resources of traditional Chinese medicine,has the natural advantages and deep foundation to develop traditional Chinese medicine health care industry.Based on Strengths,Weaknesses,Opportunities & Threats(SWOT)analysis,the advantages,disadvantages,opportunities and challenges of the development of traditional Chinese medicine health care industry in Shandong Province were deeply analyzed.SWOT matrix model was constructed to put forward targeted countermeasures and suggestions,in order to provide theoretical support and practical guidance for the healthy development of traditional Chinese medicine health care industry in Shandong Province.

Traditional Chinese medicine is an important part of Chinese traditional culture and has played an increasingly important role in the field of health care in recent years.Shandong Province,as a province with large resources of traditional Chinese medicine,has the natural advantages and deep foundation to develop traditional Chinese medicine health care industry.Based on Strengths,Weaknesses,Opportunities & Threats(SWOT)analysis,the advantages,disadvantages,opportunities and challenges of the development of traditional Chinese medicine health care industry in Shandong Province were deeply analyzed.SWOT matrix model was constructed to put forward targeted countermeasures and suggestions,in order to provide theoretical support and practical guidance for the healthy development of traditional Chinese medicine health care industry in Shandong Province.

Traditional Chinese medicine is an important part of Chinese traditional culture and has played an increasingly important role in the field of health care in recent years.Shandong Province,as a province with large resources of traditional Chinese medicine,has the natural advantages and deep foundation to develop traditional Chinese medicine health care industry.Based on Strengths,Weaknesses,Opportunities & Threats(SWOT)analysis,the advantages,disadvantages,opportunities and challenges of the development of traditional Chinese medicine health care industry in Shandong Province were deeply analyzed.SWOT matrix model was constructed to put forward targeted countermeasures and suggestions,in order to provide theoretical support and practical guidance for the healthy development of traditional Chinese medicine health care industry in Shandong Province.

Traditional Chinese medicine is an important part of Chinese traditional culture and has played an increasingly important role in the field of health care in recent years.Shandong Province,as a province with large resources of traditional Chinese medicine,has the natural advantages and deep foundation to develop traditional Chinese medicine health care industry.Based on Strengths,Weaknesses,Opportunities & Threats(SWOT)analysis,the advantages,disadvantages,opportunities and challenges of the development of traditional Chinese medicine health care industry in Shandong Province were deeply analyzed.SWOT matrix model was constructed to put forward targeted countermeasures and suggestions,in order to provide theoretical support and practical guidance for the healthy development of traditional Chinese medicine health care industry in Shandong Province.

Traditional Chinese medicine is an important part of Chinese traditional culture and has played an increasingly important role in the field of health care in recent years.Shandong Province,as a province with large resources of traditional Chinese medicine,has the natural advantages and deep foundation to develop traditional Chinese medicine health care industry.Based on Strengths,Weaknesses,Opportunities & Threats(SWOT)analysis,the advantages,disadvantages,opportunities and challenges of the development of traditional Chinese medicine health care industry in Shandong Province were deeply analyzed.SWOT matrix model was constructed to put forward targeted countermeasures and suggestions,in order to provide theoretical support and practical guidance for the healthy development of traditional Chinese medicine health care industry in Shandong Province.

Traditional Chinese medicine is an important part of Chinese traditional culture and has played an increasingly important role in the field of health care in recent years.Shandong Province,as a province with large resources of traditional Chinese medicine,has the natural advantages and deep foundation to develop traditional Chinese medicine health care industry.Based on Strengths,Weaknesses,Opportunities & Threats(SWOT)analysis,the advantages,disadvantages,opportunities and challenges of the development of traditional Chinese medicine health care industry in Shandong Province were deeply analyzed.SWOT matrix model was constructed to put forward targeted countermeasures and suggestions,in order to provide theoretical support and practical guidance for the healthy development of traditional Chinese medicine health care industry in Shandong Province.