Review on the Fabrication of Surface Functional Structures for Enhancing Bioactivity of Titanium and Titanium Alloy Implants

Titanium and its alloys have been widely applied in many biomedical fields because of its excellent mechanical properties,corrosion resistance and good biocompatibility.However,problems such as rejection,shedding and infection will occur after titanium alloy implantation due to the low biological activity of titanium alloy surface.The structures with specific functions,which can enhance osseointegration and antibacterial properties,are fabricated on the surface of titanium implants to improve the biological activity between the titanium implants and human tissues.This paper presents a comprehensive review of recent developments and applications of surface functional structure in titanium and titanium alloy implants.The applications of surface functional structure on different titanium and titanium alloy implants are introduced,and their manufacturing technologies are summarized and compared.Furthermore,the fabrication of various surface functional structures used for titanium and titanium alloy implants is reviewed and analyzed in detail.Finally,the challenges affecting the development of surface functional structures applied in titanium and titanium alloy implants are outlined,and recommendations for future research are presented.

A Dual-Task Learning Approach for Bearing Anomaly Detection and State Evaluation of Safe Region

Predictive maintenance has emerged as an effective tool for curbing maintenance costs,yet prevailing research predominantly concentrates on the abnormal phases.Within the ostensibly stable healthy phase,the reliance on anomaly detection to preempt equipment malfunctions faces the challenge of sudden anomaly discernment.To address this challenge,this paper proposes a dual-task learning approach for bearing anomaly detection and state evaluation of safe regions.The proposed method transforms the execution of the two tasks into an optimization issue of the hypersphere center.By leveraging the monotonicity and distinguishability pertinent to the tasks as the foundation for optimization,it reconstructs the SVDD model to ensure equilibrium in the model’s performance across the two tasks.Subsequent experiments verify the proposed method’s effectiveness,which is interpreted from the perspectives of parameter adjustment and enveloping trade-offs.In the meantime,experimental results also show two deficiencies in anomaly detection accuracy and state evaluation metrics.Their theoretical analysis inspires us to focus on feature extraction and data collection to achieve improvements.The proposed method lays the foundation for realizing predictive maintenance in a healthy stage by improving condition awareness in safe regions.

Expert consensus on difficulty assessment of endodontic therapy

Endodontic diseases are a kind of chronic infectious oral disease. Common endodontic treatment concepts are based on the removal of inflamed or necrotic pulp tissue and the replacement by gutta-percha. However, it is very essential for endodontic treatment to debride the root canal system and prevent the root canal system from bacterial reinfection after root canal therapy(RCT). Recent research, encompassing bacterial etiology and advanced imaging techniques, contributes to our understanding of the root canal system’s anatomy intricacies and the technique sensitivity of RCT. Success in RCT hinges on factors like patients, infection severity, root canal anatomy, and treatment techniques. Therefore, improving disease management is a key issue to combat endodontic diseases and cure periapical lesions. The clinical difficulty assessment system of RCT is established based on patient conditions, tooth conditions, root canal configuration, and root canal needing retreatment, and emphasizes pre-treatment risk assessment for optimal outcomes. The findings suggest that the presence of risk factors may correlate with the challenge of achieving the high standard required for RCT. These insights contribute not only to improve education but also aid practitioners in treatment planning and referral decision-making within the field of endodontics.

Tetrahedral framework nucleic acids/hyaluronic acidmethacrylic anhydride hybrid hydrogel with antimicrobial and anti-inflammatory properties for infected wound healing

Bacterial resistance and excessive inflammation are common issues that hinder wound healing.Antimicrobial peptides(AMPs)offer a promising and versatile antibacterial option compared to traditional antibiotics,with additional anti-inflammatory properties.However,the applications of AMPs are limited by their antimicrobial effects and stability against bacterial degradation.TFNAs are regarded as a promising drug delivery platform that could enhance the antibacterial properties and stability of nanodrugs.Therefore,in this study,a composite hydrogel(HAMA/t-GL13K)was prepared via the photocross-linking method,in which tFNAs carry GL13K.The hydrogel was injectable,biocompatible,and could be instantly photocured.It exhibited broad-spectrum antibacterial and anti-inflammatory properties by inhibiting the expression of inflammatory factors and scavenging ROS.Thereby,the hydrogel inhibited bacterial infection,shortened the wound healing time of skin defects in infected skin full-thickness defect wound models and reduced scarring.The constructed HAMA/tFNA-AMPs hydrogels exhibit the potential for clinical use in treating microbial infections and promoting wound healing.

Combination of eddy current and heat treatment for crack healing and mechanical-property improvement in magnesium alloy tube

The continuous eddy current pulse treatment(ECPT)combined with heat treatment was employed to heal the microcracks in spin formed Mg alloy tubes and improve their mechanical properties in this study.The results show that all the microcracks in different tube specimens were almost healed after different continuous ECPT schemes up to 15 cycles.The schemes with less cooling intervals exhibited better healing effect and increased the strength and elongation of Mg alloy tubes more obviously.After aging treatment,the strength improvement of the specimens with ECPT was more remarkable than that of the specimens without ECPT,and the elongation decrease of the specimens with ECPT was less evident than that of specimens without ECPT due to the segregation of RE elements on the crack surface.Besides,after solution treatment,the strength reduction and ductility improvement of the specimens with ECPT were more pronounced than that of the specimens without ECPT owing to the notable decrease of dislocation density of the specimens with ECPT.Both narrowed cracks induced by ECPT and the segregation of precipitates in the vicinity of microcrack surface during aging treatment contributed to the maximum strength in the as-spun specimens with ECPT followed by aging treatment.

The effect of Supplementing Qi and Nourishing Yin combined with chemotherapy for lung cancer： a meta-analysis

Objective： To evaluate whether herbs of supplementing Qi and nourishing Yin combined with chemotherapy （versus chemotherapy alone） improve survival, increase tumor response, improve performance status or reduce chemotherapy toxicity in patients with lung cancer. Methods： Searching the randomized controlled trials （RCT） studies from the databases （China HowNet database, Wan Fang database, VIP database, Master Thesis and Pubmed） between January 2013 and January 2017. RevMan 5.3 software was used to evaluate the quality of these collected papers. Results： Of 48 potentially relevant publications, 10 randomized studies representing 691 patients met inclusion criteria with 369 cases in the supplementing Qi and nourishing Yin plus Chemotherapy group （Herbs ＋ Chem group） and 322 cases in Chemotherapy group （Chem only group）. There were significant differences between Herbs ＋ Chem group and Chem only group in improving the treatment efficacy and reducing the side effects of chemotherapy （P 〈 0.001 for all）. There were also significant differences between the two groups in tumor response and quality of life （P 〈 0.001 for all）. Conclusion： Herbs of supplementing Qi and nourishing Yin may increase chemotherapy effectiveness, reduce chemotherapy toxicity and improve the quality of life of patients with lung cancer when combined with chemotherapy.

Traditional Chinese medicine combined with chemotherapy in the treatment ofliver cancer： a meta-analysis

Objective： To analyze the clinical efficacy of traditional Chinese medicine （TCM） combined with chemotherapy inthe treatment of primary liver cancer on the basis of meta-analysis software. Method： Retrieval randomizedcontrolled trials （RCT） of TCM combined with chemotherapy in the treatment of the liver cancer from the networkdatabase （such as MEDLINE, EMBASE, PUBMED, Chinese CNKI database, Wanfang database, VIP databaseetc.）. The retrieval period was from January 2011 to July 2017. Results： A total of 16 RCT studies were includedand involving 1873 patients, with 949 patients in the treatment （TCM with chemotherapy） group and 924 patientsin the control group （chemotherapy alone）. Meta-analysis results suggest that TCM combined with chemotherapyin the treatment of primary hepatocellular carcinoma can improve curative effect, improve the degree of ascites ofpatients, improve the quality of life of patients and alleviate chemotherapy side effects. Conclusion： TCMcombined with chemotherapy in the treatment of primary liver cancer is helpful to improve the short term curativeeffect, improve the quality of life of patients, and alleviate the toxic and side effects.

Effect of grain refinement induced by wire and arc additive manufacture (WAAM) on the corrosion behaviors of AZ31 magnesium alloy in NaCl solution

Additive manufacturing(AM)of Mg alloys has become a promising strategy for producing complex structures,but the corrosion performance of AM Mg components remains unexploited.In this study,wire and arc additive manufacturing(WAAM)was employed to produce single AZ31 layer.The results revealed that the WAAM AZ31 was characterized by significant grain refinement with non-textured crystallographic orientation,similar phase composition and stabilized corrosion performance comparing to the cast AZ31.These varied corrosion behaviors were principally ascribed to the size of grain,where cast AZ31 and WAAM AZ31 were featured by micro galvanic corrosion and intergranular corrosion,respectively.

Geology and mineralization of the Bayan Obo supergiant carbonatite-type REE-Nb-Fe deposit in Inner Mongolia, China: A review

The Bayan Obo supergiant carbonatite-related rare-earth-element-niobium-iron(REE-Nb-Fe) endogenetic deposit(thereafter as the Bayan Obo deposit), located at 150 km north of Baotou City in the Inner Mongolia Autonomous Region, is the largest rare-earth element(REE) resource in the world. Tectonically,this deposit is situated on the northern margin of the North China Craton and adjacent to the Xing’anMongolian orogenic belt to the south. The main strata within the mining area include the Neoarchean Se’ertengshan Group and the Mesoproterozoic Bayan Obo Group. Generally, the rare earth, niobium, and iron mineralization within the deposit are intrinsically related to the dolomite carbonatites and the extensive alteration of the country rocks caused by the carbonatite magma intrusion. The alteration of country rocks can be categorized into three types: contact metasomatism(anti-skarn and skarn alteration), fenitization,and hornfelsic alternation. As indicated by previous studies and summarized in this review, the multielement mineralization at Bayan Obo is closely associated with the metasomatic replacement of siliceous country rocks by carbonatite magmatic-hydrothermal fluids. The metasomatic process is comparable to the conventional skarnification that formed due to the intrusion of intermediate-acid magmatic rocks into limestone strata. However, the migration pattern of Si O2, Ca O, and Mg O in this novel metasomatic process is opposite to the skarn alteration. Accordingly, this review delineates, for the first time, an antiskarn metallogenic model for the Bayan Obo deposit, revealing the enigmatic relationship between the carbonatite magmatic-hydrothermal processes and the related iron and rare earth mineralization.Moreover, this study also contributes to a better understanding of the REE-Nd-Fe metallogenetic processes and the related fluorite mineralization at the Bayan Obo deposit.

Causal associations of brain structure with bone mineral density:a large-scale genetic correlation study

In this study,we aimed to investigate the causal associations of brain structure with bone mineral density(BMD).Based on the genome-wide association study(GWAS)summary statistics of 1325 brain imaging-derived phenotypes(BIDPs)of brain structure from the UK Biobank and GWAS summary datasets of 5 BMD locations,including the total body,femoral neck,lumbar spine,forearm,and heel from the GEFOS Consortium,linkage disequilibrium score regression(LDSC)was conducted to determine the genetic correlations,and Mendelian randomization(MR)was then performed to explore the causal relationship between the BIDPs and BMD.Several sensitivity analyses were performed to verify the strength and stability of the present MR outcomes.To increase confidence in our findings,we also performed confirmatory MR between BIDPs and osteoporosis.LDSC revealed that 1.93%of BIDPs,with a false discovery rate(FDR)<0.01,were genetically correlated with BMD.Additionally,we observed that 1.31%of BIDPs exhibited a significant causal relationship with BMD(FDR<0.01)through MR.Both the LDSC and MR results demonstrated that the BIDPs“Volume of normalized brain,”“Volume of gray matter in Left Inferior Frontal Gyrus,pars opercularis,”“Volume of Estimated Total Intra Cranial”and“Volume-ratio of brain segmentation/estimated total intracranial”had strong associations with BMD.Interestingly,our results showed that more left BIDPs were causally associated with BMD,especially within and around the left frontal region.In conclusion,a part of the brain structure causally influences BMD,which may provide important perspectives for the prevention of osteoporosis and offer valuable insights for further research on the brain-bone axis.

Development and application of hepatocellular carcinoma risk prediction model based on clinical characteristics and liver related indexes

BACKGROUND Hepatocellular carcinoma(HCC)is difficult to diagnose with poor therapeutic effect,high recurrence rate and has a low survival rate.The survival of patients with HCC is closely related to the stage of diagnosis.At present,no specific serolo-gical indicator or method to predict HCC,early diagnosis of HCC remains a challenge,especially in China,where the situation is more severe.AIM To identify risk factors associated with HCC and establish a risk prediction model based on clinical characteristics and liver-related indicators.METHODS The clinical data of patients in the Affiliated Hospital of North Sichuan Medical College from 2016 to 2020 were collected,using a retrospective study method.The results of needle biopsy or surgical pathology were used as the grouping criteria for the experimental group and the control group in this study.Based on the time of admission,the cases were divided into training cohort(n=1739)and validation cohort(n=467).Using HCC as a dependent variable,the research indicators were incorporated into logistic univariate and multivariate analysis.An HCC risk prediction model,which was called NSMC-HCC model,was then established in training cohort and verified in validation cohort.RESULTS Logistic univariate analysis showed that,gender,age,alpha-fetoprotein,and protein induced by vitamin K absence or antagonist-II,gamma-glutamyl transferase,aspartate aminotransferase and hepatitis B surface antigen were risk factors for HCC,alanine aminotransferase,total bilirubin and total bile acid were protective factors for HCC.When the cut-off value of the NSMC-HCC model joint prediction was 0.22,the area under receiver operating characteristic curve(AUC)of NSMC-HCC model in HCC diagnosis was 0.960,with sensitivity 94.40%and specificity 95.35%in training cohort,and AUC was 0.966,with sensitivity 90.00%and specificity 94.20%in validation cohort.In early-stage HCC diagnosis,the AUC of NSMC-HCC model was 0.946,with sensitivity 85.93%and specificity 93.62%in training cohort,and AUC was 0.947,with sensitivity 89.10%and specificity 98.49%in validation cohort.CONCLUSION The newly NSMC-HCC model was an effective risk prediction model in HCC and early-stage HCC diagnosis.

鼻内镜下低温等离子射频消融与传统方式切除鼻前庭囊肿的临床疗效观察

目的比较鼻内镜下低温等离子与传统方式(经齿龈沟径路)行鼻前庭囊肿切除的临床疗效观察分析。方法选取青海大学附属医院耳鼻咽喉科2010年1月-2016年1月经手术治疗的鼻前庭囊肿患者68例,并将其按照随机分组的方式分为对照组和实验组,其中对照组34例,实验组34例。对照组患者采取传统方式(经齿龈沟径路)行囊肿切除,实验组采取鼻内镜下低温等离子方式行囊肿切除。比较两组患者手术时间、术中出血情况、术后疼痛情况、术后伤口愈合时间及手术并发症等。结果实验组手术时间、术中出血量、术后疼痛及伤口愈合时间均优于对照组(P<0.05),手术并发症发生率明显低于对照组(P<0.05)。结论鼻内镜下低温等离子术治疗鼻前庭囊肿具有痛苦少、创伤小、疗效好和并发症少等优点,值得临床应用及推广。

Expert consensus on dental caries management

Dental Caries is a kind of chronic oral disease that greatly threaten human being’s health.Though dentists and researchers struggled for decades to combat this oral disease,the incidence and prevalence of dental caries remain quite high.Therefore,improving the disease management is a key issue for the whole population and life cycle management of dental caries.So clinical difficulty assessment system of caries prevention and management is established based on dental caries diagnosis and classification.Dentists should perform oral examination and establish dental records at each visit.When treatment plan is made on the base of caries risk assessment and carious lesion activity,we need to work out patient-centered and personalized treatment planning to regain oral microecological balance,to control caries progression and to restore the structure and function of the carious teeth.And the follow-up visits are made based on personalized caries management.This expert consensus mainly discusses caries risk assessment,caries treatment difficulty assessment and dental caries treatment plan,which are the most important parts of caries management in the whole life cycle.

Key Problems in Microforming Processes of Microparts

From the viewpoint of production engineering, microforming is considered as an effective process to fabricate various microparts. Several key problems in microforming processes were investigated. A new microforming apparatus with a high stiffness piezoelectric actuator as the punch driver was developed to produce microparts.To improve the forming abilities and locate the billets, a floating microdie was designed. The size effects of the billets and die cavities on the microforming abilities were studied with upsetting and coining tests, respectively.And the isothermal microforming process of microgears was performed with the developed microforming apparatus. Several analysis methods were used to evaluate the forming quality of the microparts.

社会主义新农村建设背景下村干部工作压力源研究—基于2010年对陕西省河阳县10个乡镇110位村干部的调查

基于2010年10月对陕西省河阳县10个乡镇110位村干部的半结构式问卷调查,运用探索性因子分析技术对村干部在新农村建设过程中所面临的工作压力进行了实证研究。研究发现,村干部的工作压力源主要来自于:外界对村干部工作期望、工作难度、角色冲突、社会声望和权威、职业前景等五个方面。进一步研究还发现,在以上五个方面,角色冲突的压力最大;其次是他人对工作的期望;再次是工作难度。然而,社会声望和权威、职业前景的压力,相对较弱。

Effect of Galla chinensis on the remineralization of two bovine root lesions morphous in vitro

The present study aims to evaluate the effect of Galla chinensis compounds on the remineralization of two artificial root lesions morphous in vitro. Sixty bovine dentine blocks were divided into two groups and individually treated with two levels of demineralization solutions to form erosive and subsurface artificial carious lesions in vitro. Each group was then divided into three subgroups, each of which were treated with a remineralization solution （positive control）, deionized water （negative control）, or 4 000 mg-L-1 aqueous solutions of Galla chinensis extract. The dentine blocks were then subjected to a pH-cycling regime for 7 days. During the first 4 days, the daily cycle included 21-h deal and 3-h demineralization applications. The dentine blocks were dealt with the entire day during the remaining 3 days. Two specimens from each of the treatment groups were selected and observed under a polarized light microscope. Data collected using a laser scanning confocal microscope were computerized and analyzed. Galla chinensis extract clearly enhanced the remineralization of both erosive lesion and subsurface lesion patterns in the specimens （P〈0.05）. The level of remineralization of the erosive lesion by Galla chinensis extract was lower than that of the subsurface lesion （P〈0.05）. In addition, the remineralization of the subsurface lesion by Galla chinensis extract was higher than that of the remineralization solution （P〈0.05）. No significant difference between the remineralization of erosive lesions by Galla chinensis extract and the remineralization solution was observed （P〉0.05）. So Galla chinensis extract has the potential to improve the remineralization of artificial root lesions under dynamic pH-cyclic conditions, indicating its potential use as a natural remineralization medicine.

CMA down-regulates p53 expression through degradation of HMGB1 protein to inhibit irradiation-triggered apoptosis in hepatocellular carcinoma

AIM To investigate the mechanism of chaperone-mediated autophagy(CMA)-induced resistance to irradiationtriggered apoptosis through regulation of the p53 protein in hepatocellular carcinoma(HCC). METHODS Firstly, we detected expression of lysosome-associated membrane protein 2a(Lamp-2a), which is the key protein of CMA, by western blot in Hep G2 and SMMC7721 cells after irradiation. We further used sh RNA Lamp-2a HCC cells to verify the radioresistance induced by CMA. Next, we detected the HMGB1 and p53 expression after irradiation by western blot, and we further used RNA interference and ethyl pyruvate(EP), as a HMGB1 inhibitor, to observe changes of p53 expression. Finally, an immunoprecipitation assay was conducted to explore the interaction between Lamp-2a and HMGB1, and the data were analyzed. RESULTS We found the expression of Lamp-2a was increased on irradiation while apoptosis decreased in Hep G2 and SMMC7721 cells. The apoptosis was increased markedly in the sh RNA Lamp-2a Hep G2 and SMMC7721 cells as detected by western blot and colony formation assay. Next, we found p53 expression was gradually reduced on irradiation but obviously increased in sh RNA Lamp-2a cells. Furthermore, p53 increased the cell apoptosis on irradiation in Hep3B(p53-/-) cells. Finally, p53 levels were regulated by HMGB1 as measured through RNA interference and the EP treatment. HMGB1 was able to combine with Lamp-2a as seen by immunoprecipitation assay and was degraded via the CMA pathway. The decreased HMGB1 inhibited p53 expression induced by irradiation and further reduced the apoptosis in HCC cells. CONCLUSION CMA pathway activation appears to down-regulate the susceptibility of HCC to irradiation by degrading HMGB1 with further impact on p53 expression. These findings have clinical relevance for radiotherapy of HCC.

Thermal resistance matrix representation of thermal effects and thermal design of microwave power HBTs with two-dimensional array layout

Based on the thermal network of the two-dimensional heterojunction bipolar transistors(HBTs) array, the thermal resistance matrix is presented, including the self-heating thermal resistance and thermal coupling resistance to describe the self-heating and thermal coupling effects, respectively.For HBT cells along the emitter length direction, the thermal coupling resistance is far smaller than the self-heating thermal resistance, and the peak junction temperature is mainly determined by the self-heating thermal resistance.However, the thermal coupling resistance is in the same order with the self-heating thermal resistance for HBT cells along the emitter width direction.Furthermore, the dependence of the thermal resistance matrix on cell spacing along the emitter length direction and cell spacing along the emitter width direction is also investigated, respectively.It is shown that the moderate increase of cell spacings along the emitter length direction and the emitter width direction could effectively lower the self-heating thermal resistance and thermal coupling resistance,and hence the peak junction temperature is decreased, which sheds light on adopting a two-dimensional non-uniform cell spacing layout to improve the uneven temperature distribution.By taking a 2 × 6 HBTs array for example, a twodimensional non-uniform cell spacing layout is designed, which can effectively lower the peak junction temperature and reduce the non-uniformity of the dissipated power.For the HBTs array with optimized layout, the high power-handling capability and thermal dissipation capability are kept when the bias voltage increases.

Particulate Matters Pollution Characteristic and the Correlation between PM (PM_2.5, PM₁₀) and Meteorological Factors during the Summer in Shijiazhuang

In recent years, the haze occurs frequently and air pollution is getting worse in Beijing-Tianjin-Hebei Region, China. The particulate matter pollution characteristic researches are playing a sig-nificant role especially in the districts where have higher concentration PM and air pollution. In this study, we collected daily particulate matter (PM10, PM2.5) mass concentration data from 7 air pollution monitoring stations in Shijiazhuang City, Hebei, China over a 3-month period from June to August to investigate particulate matter pollution characteristic and the relationship with me-teorological conditions. Statistical results show that PM10 is the major pollutant in Shijiazhuang City;the average daily concentrations of PM2.5 and PM10 are 94.45 μg/m3 and 219.15 μg/m3, respectively. The daily average of PM10 and PM2.5 level over the period exceeded the first grade of the daily average limit of the ambient air quality standards (GB3095-2012). And there is a significantly positive correlation between atmospheric pressure and particulate matter pollution, but there is a significantly negative correlation between atmospheric temperature and PM concentrations. Precipitation has a clear role mainly in the coarse particles;however, there has little effect on fine particulate matter. Relative humidity and wind speed have a poor correlation with atmospheric pollutant concentrations (not remarkably high).

Mechanism of size effects in microcylindrical compression of pure copper considering grain orientation distribution

In microscale deformation, the magnitudes of specimen and grain sizes are usually identical, and size- dependent phenomena of deformation behavior occur, namely, size effects. In this study, size effects in micro- cylindrical compression were investigated experimentally. It was found that, with the increase of grain size and decrease of specimen size, flow stress decreases and inhomogeneous material flow increases. These size effects tend to be more distinct with miniaturization. Thereafter, a modified model considering orientation distribution of surface grains and continuity between surface grains and inner grains is developed to model size effects in micro- forming. Through finite element simulation, the effects of specimen size, grain size, and orientation of surface grains on the flow stress and inhomogeneous deformation were analyzed. There is a good agreement between experimental and simulation results.