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As a new type of functional and structural material, the porous metal materials have been widely used in the fields of sound absorption, energy absorption, fluid distribution, heat exchange, catalysis, filtration, and separation, which are the most widely used in the field of filtration and separation. Porous metal materials can achieve the liquid−solid and gas−solid filtration separation for the different fluids in the fields of petroleum and petrochemical, fine chemical, coal chemical, and other fields, and the requirements for the materials and mechanical properties of the porous metal materials used in the different fields are also different. The preparation process of porous metal materials used for filtration is relatively mature, but there is little investigation on the corrosion resistance and mechanical properties of the porous metal materials, which will directly affect the use effect and life of such materials. The research progress on the mechanical properties and corrosion resistance of the porous metal materials used for filtration in recent years was briefly reviewed in this paper, and the existing problems in the corrosion and mechanical behavior of such materials were discussed. Finally, the research direction of the porous metal materials used for filtration was prospected.

Objective To explore the role of apoliprotein D (APOD) in the proliferation and migration of human dental pulp cells (DPCs) and to provide a basis for the use of APOD to promote pulp regeneration. Methods APOD ex⁃ pression in human dental pulp cells was inhibited by siRNA. The inhibition effect of APOD was confirmed by qPCR and Western blot. After APOD inhibition, colony formation experiments and CCK8 assays were employed to confirm the proliferation ability of dental pulp cells. Transwell assays were used to verify the cell migration ability after the inhibi⁃ tion of APOD expression. Results After inhibiting APOD expression, the colony formation rate in the si⁃apod group was reduced compared with the NC group, and the difference was statistically significant (t＝7.624, P＝0.002). The CCK8 experiment showed that the OD value in the si⁃apod group decreased at 3, 5 and 7 d compared with that in the NC group (P < 0.05). Transwell results showed that the number of cell divisions was 57.25 ± 4.03 in the si⁃apod group and 154.50 ± 8.39 in the NC group, and the difference was statistically significant (t＝10.45, P < 0.001). Conclusion Inhibition of APOD expression in dental pulp cells inhibits their proliferation and migration ability.

Objective To analyze the morphology and incidence of middle mesial canal (MM) and isthmus in the mandibular first permanent molar by cone⁃beam computed tomography (CBCT). Methods Statistical analysis was per⁃ formed on images from patients who underwent CBCT examination in the Department of Radiology at Stomatological Hospital, Southern Medical University. Samples exhibiting root canal treatment, root resorption and calcification were ex⁃ cluded. Data regarding sex, age, the presence or absence of isthmus and MM, and the number of roots and root canals were recorded. Results Of the 217 mandibular first molar samples, 8 (3.7%) had an MM, and 2 (0.9%) had an inde⁃ pendent apical foramen. The overall incidence rate of isthmus was 57.1%; this rate was 50.7% in the cervical third of the root canal, 17.5% in the middle third, and 13.4% in the apical third. The incidence rate of isthmus was 61.8% on the left side, 52.3% on the right side, 58.7% in males, and 55.8% in females. No significant difference was found be⁃ tween the left and right sides or between females and males (P > 0.05). The incidence rate of isthmus in people under 60 was greater than 50% but was significantly lower in people older than 60. Conclusion Only a very small propor⁃ tion of MMs have an independent apical foramen in the mandibular first molar. The incidence of isthmus in the mesial root of the mandibular first permanent molar is high, and isthmus usually occurs in the cervical third of the root canal. During root canal treatment or apical surgery, attention should be given to the physical and chemical preparation of the isthmus.

Objective Explore the role and status of tumor necrosis factor receptor⁃associated factor 6 (TRAF6) in the inflammatory response of human osteoblast⁃like cells MG63 which was triggered by Enterococcus faecalis (E. faeca⁃ lis) and its lipoteichoic acid (LTA). Methods SiRNA technology was applied to silence the TRAF6 gene of MG63 cells, Using E.faecelis and its LTA to stimulate the silence MG63 cells with different hours. After that, using real⁃time PCR technology to detect toll⁃like receptor 2 (TLR2) and TRAF6 gene expression and using ELISA assay to detect pro⁃ inflammatory cytokines interleukin⁃1β and TNF⁃alpha expression levels. Results When MG63 cells was infected by E. faecalis, its LTA, TLR2 and TRAF6 gene level has increased to varying degrees (P < 0.05); interleukin⁃1β and TNF⁃ alpha expression was significantly higher (P < 0.05). When TRAF6 gene of MG63 cells was silenced by siRNA, pro⁃in⁃ flammatory cytokines interleukin ⁃ 1β, interleukin ⁃6, interleukin ⁃8 and TNF ⁃alpha expression decreased significantly (P < 0.05). Conclusion E. faecalis and its toxic components is identified by MG63 cells mainly through TLR2 recep⁃ tors. The major virulence factor in periapical infections caused by E. faecalis is LTA.

Seeding depth is one of the indicators required by agricultural seeding technology. Seeding depth too large, too small or not consistent will cause low germination rate, slow seedling growth and other problems. It will affect late crop growth and finally reduce yield. In China, conventional tillage is widely used. But with the development of modern agricultural science and technology, the quality of soil in conventional tillage can not meet the requirements of the crop growth. Under the circumstances, conservation tillage arises in china, but the residues on surface of conservation tillage and the surface roughness is larger than conventional tillage. So working depth control is one of the keys for planter design. In order to control working depth constantly, profiling mechanism was adopted in planter for furrow opener, which was one of the most important ways to control working depth. Profiling mechanism mainly included whole profile modeling and unit profile modeling, of which whole profile modeling was simple, but the stability of its working depth was poorer. So whole profile modeling and unit profile modeling were adopted in most planter to keep working depth constantly. At present, the passive regulating mode was more used to control working depth in domestic, such as adjusting spring and parallelogram linkage. In other countries, in order to control working depth, besides the passive regulating mode, the active regulating mode was also adopted, which was controlled by electro-hydraulic technology and could realize the accurate control of working depth. Therefore, in order to improve the stability of no-till planter seeding depth, a depth of furrow opening control system was designed. The system included a surface height detection mechanism, four-connecting-rod profiling mechanism, PLC control system and hydraulic system. In the system, working depth was controlled by feedback and synchronization of profiling in real-time, the surface height by checking could reach 200 mm, and the capacity of profile modeling was 370 mm. In hydraulic system, through analyzing the work load and the speed of the system, it was determined that the rated system pressure was 10 MPa and the rated flow was 40 L/min. The average speeds of rise and fall of furrow opener were 78.7 and 102.8 mm/s, respectively. Through various tests on the depth control system, the working parameters of the control system were obtained. The system response time was 0.12 s, and working depth stability was more than 90%. In the speed of 5 km/h and working depths of 30, 50 and 70 mm, the stabilities of working depth were 90.98%, 91.45% and 92.32%, respectively, and the measurement error of the system was less than or equal to 0.54%. Therefore, it can meet the requirements of the standard on working depth stability. The research of the depth of furrow opening control system provides the reference for designing planter and understanding its furrow opening depth control mechanism. [ABSTRACT FROM AUTHOR]

In order to solve the problem of seedlings leakage planting caused by the lack of plug seedlings in trays during with the all automatic transplanter working, an automatic recognition and control device for vegetable plug seedling transplanter was designed. In contrast to the home and abroad information, the design considered the domestic user price affordability and practicality. In this device, a stepping motor was used for driving the seedling disc horizontal motion and another was used for driving the seedling disc vertical motion. Four photo-electric sensors as the seedling recognition device were fitted on both sides of the seedling gripper and seedling disc, which can detect of seedling shortage from four directions. A programmable logic controller (PLC) was used to control clamping seedling gripper motion and the seedling disc transport along horizontal and vertical direction. A touch screen as man-machine interface can set the parameter to fit different size seedling disc, which can also choose manually or automatic control method. In this paper, a comparative experiment f was carried out at different transplanting velocity under the condition of automatic recognition system or one month old pepper seedling. The results showed that it could work effectively. The movement of the seedling trigger photoelectric sensor produced a signal, so that the seedlings were stopped and clamped away when moving to the position of the seedling gripper. On the contrary, the lack of seedling lattice cannot trigger photoelectric sensor, on arrival will not stop the seedling fetching device position, but quickly through, directly send the next seedling to stop on position of the seedling gripper, waiting for the clamping seedling gripper. This improves the seedling grab efficiency, reducing the leakage rate of transplanting machine plant. Automatic recognition and control device had low misjudge rate when transplanting speed was form 60 to 120 seedling per minutes. When transplanting speed was from 60 to 90 seedling per minute, the transplanter had well leakage plantings rate and throwing seedlings rate that can effectively work at transplanting seedling. The response speed of automatic recognition and control device can work at high speed transplanter. The leakage transplanting rate with automatically seedlings picking recognition control system was 12% lower than without the automatically seedlings picking control system. The device achieved the objective of reducing leakage rate purpose. Relative to not used for automatic identification of transplanting seedling mode, it is reduced about 12% that the leakage rate of the whole system of plant in 60-90 seedling /min transplanting speed. Leakage rate of transplanting machine plant is close to the practical level of planting. It achieved the purpose of reducing the leakage rate of planting. Through observation and analysis during experiments, if the conveying of seedling disk was changed to horizontal, it can maximize the seedling erect and reducing sensor misjudgment caused by seedling roll or tilt, the identification rate was improved. The system was only carried out in the laboratory test, but field test has not yet performed. In field operation, some factor may affect the automatic recognition and seedling fetching device reliability and stability, such as vibration of machines, interference of the sensor by sunshine outdoor. These need further test and examination. More field experiment needs to be tested for the influences of machine vibration and sunlight to the photoelectric sensor. [ABSTRACT FROM AUTHOR]

Objective: To explore the short-term outcomes of 3D-printing stand-alone artificial vertebral body (AVB) in the surgical procedure of anterior cervical corpectomy and fusion (ACCF)., Methods: Following the proposal of IDEAL (idea, development, exploration, assessment, and long-term follow-up) framework, we designed and conducted this single-armed, retrospective cohort study. The patients with cervical spondylotic myelopathy were recruited, and these patients exclusively received the surgical procedure of single-level ACCF in our single center. After the process of corpectomy, the size was tailored using different trials and the most suitable stand-alone AVB was then implanted. This AVB was manufactured by the fashion of 3D-printing. Two pairs of screws were inserted in an inclined way into the adjacent vertebral bodies, to stabilize the AVB. The participants were regularly followed-up after the operation. Their clinical data were thoroughly reviewed. We assessed the neurological status according to Japanese Orthopedic Association (JOA) scale. We determined the fusion based on imaging examination six months after the operation. The recorded clinical data were analyzed using specific software and they presented in suitable styles. Paired t test was employed in comparison analysis., Results: In total, there were eleven patients being recruited eventually. The patients were all followed up over six months after the operation. The mean age of the cohort was (57.2±10.2) years. The mean operation time was (76.1±23.1) min and the median bleeding volume was 150 (100, 200) mL. The postoperative course was uneventful for all the cases. Dysphagia, emergent hematoma, and deterioration of neurological function did not occur. Mean JOA scores were 13.2±2.2 before the operation and 16.3±0.8 at the final follow-up, which were significantly different ( P < 0.001). The mean recovery rate of neurological function was 85.9%. By comparing the imaging examinations postoperatively and six months after the operation, we found that the average subsidence length was (1.2±1.1) mm, and that there was only one cases (9.1%) of the severe subsidence (>3 mm). We observed significant improvement of cervical lordosis after the operation ( P =0.013). All the cases obtained solid fusion., Conclusion: 3D-printing stand-alone AVB presented favorable short-term outcome in one-level ACCF in this study. The fusion rate of this zero-profile prosthesis was satisfactory and the complication rate was relatively low.

Objective: To explore the effects of innovated technologies and products on improving outcomes and decreasing medical costs by analyzing a total and subtotal medical costs of patients with atlantoaxial disorders., Methods: The medical costs of 1 489 patients with atlantoaxial disorders from Peking University Third Hospital from 2005 to 2014, who received innovated technologies and products treatment were retrospectively analyzed and compared.Descriptive analysis and ANOVA were used for statistical analysis, and SPSS 19.0 was used to analyze data., Results: From 2005 to 2014, under the situation of a general increase in medical cost by 327%, the total medical costs were stable for patients who used innovated technologies and products for treatment, fluctuating from 20 851 in 2005 to 20 878 in 2014; however, the cases of operation increased year by year, from 88 in 2005 to 163 in 2014; the average length of stay decreased from 21 in 2005 to 10 in 2014; the total cases of transfusion were 22 from 2005 to 2014; the safety, stability and feasibility of the innovated technologies and products were illustrated through the decrease of average length of stay, the reduction of bleeding and the significance of outcomes., Conclusion: It is illustrated that the innovated technologies and products not only decrease patients' suffering and medical costs but also are safe, stable and feasible.

Objective: To evaluate the prognostic factors of postoperative stroke in general and orthopedic surgeries using a nested case-control design., Methods: The retrieval of information was performed from the medical records database in the Peking University Third Hospital. A total of 596 records with stroke diagnosis from January 2009 to December 2011 were recruited as the study cases, among which 29 cases were diagnosed with stroke occurred postoperatively. 174 cases with similar surgical types, date of operation and anesthesia technique were explored as control group according to the principle of the nested case-control design. The data were analyzed using Logistic regression model., Results: Univariate analysis showed that age, hypertension, diabetes, stroke or TIA history, non-atrial arrhythmias during surgery were prognostic factors for postoperative stroke. Logistic regression analysis showed that patients with stroke or TIA history, atrial fibrillation and age were independent prognostic factors for postoperative stroke, stroke or TIA history were the most significant factor associated with postoperative stroke (OR=13.01), followed by atrial fibrillation (OR=7.77) and age (OR=6.40)., Conclusion: Stroke or TIA history, atrial fibrillation, and age are independent prognostic factors for postoperative stroke. Hypertension, diabetes, and non-atrial arrhythmias during surgery are prognostic factors for postoperative stroke.

Objectives: To investigate the effect of C(2-7) laminoplasty on postoperative anterior cord space (ACS) compared with C(3-7) laminoplasty, and to provide evidence for reasonable enlargement of decompression range cephalad., Methods: Fifty-seven Patients underwent cervical laminoplasty from February 2008 to October 2011 were studied retrospectively, which were divided into two groups by decompression range: Group C(3-7) and Group C(2-7). The pre-and post operative JOA scores,VAS scores of neek and shoulder pain, and cervical alignment were compared in each group. The postoperative ACS at each level from C(2-3) to C(7)-T(1) measured on MRI were compared between the two groups., Results: The postoperative JOA scores increased significantly in both groups. VAS scores and cervical alignment showed no significant difference. ACS at C(2-3) and C(3-4) was 6.13 mm (95%CI: 5.71-6.55) and 6.60 mm (95%CI: 6.10-7.11) respectively in Group C(3-7), which increased 2.5 mm and 2.1 mm respectively in Group C2-7 at the same segment, there was significant difference (P < 0.01). However, there was no significant difference of ACS at C(4-5) and any other caudal levels between the two groups., Conclusions: Compared with conventional C(3-7) laminoplasty, the extensive decompression cephalad to C(2) leads to larger ACS at C(2-3) and C(3-4). When the mid-sagittal diameter of anterior compression is more than 6.10 mm at C(3-4), C(3-7) laminoplasty may cause insufficient decompression, and enlargement of decompression range cephalad should be considered.

Objective: To provide reference for correct clinical treatment by summarizing the characteristics and surgical experience in spinal deformity of the upper thoracic (T(1)-T(4)) short angular kyphosis., Methods: Medical history was taken in 15 cases are reviewed. The results of X-ray and MRI examinations were analyzed. The kyphotic angles were measured using the Cobb technique. All cases underwent the anterior spinal cord decompression, by posterolateral approach in 4 cases and posterior in 11 cases., Results: Kyphosis was congenital in 7 cases and due to tuberculosis approach in 8 was. The average age at deformity was first noted was 3.6 years in 7 congenital cases and 9.0 years in 8 tuberculosis cases. All cases had neurologic deficits. The mean kyphosis was 86.5 degrees (range, 45 - 100 degrees). The delay between first observation of the deformity and subsequent neurologic loss was 16.5 years and 18.1 years respectively. The operation failed in 1 case. 13 cases were followed up, with an average 42 months. Seven cases showed improvement, 2 no change and 4 deterioration in neurologic deficit., Conclusions: In cases of or tuberculosis kyphosis, the usual time for kyphosis to occur is during the preadolescent growth spurt. Neurologic deficits may occur without treatment and will be always progressive. The result of operation is not satisfactory. Early diagnosis and adequate management of kyphosis will prevent progression and thus any possible spinal cord compression. Early fusion is usually necessary to control the kyphosis.