Multifunctional AlPO_(4)reconstructed LiMn_(2)O_(4)surface for electrochemical lithium extraction from brine

LiMn_(2)O_(4)(LMO)electrochemical lithium-ion pump has gained widespread attention due to its green,high efficiency,and low energy consumption in selectively extracting lithium from brine.However,collapse of crystal structure and loss of lithium extraction capacity caused by Mn dissolution loss limits its industrialized application.Hence,a multifunctional coating was developed by depositing amorphous AlPO_(4)on the surface of LMO using sol-gel method.The characterization and electrochemical performance test provided insights into the mechanism of Li^(+)embedment and de-embedment and revealed that multifunctional AlPO_(4)can reconstruct the physical and chemical state of LMO surface to improve the interface hydrophilicity,promote the transport of Li^(+),strengthen cycle stability.Remarkably,after 20 cycles,the capacity retention rate of 0.5AP-LMO reached 93.6%with only 0.147%Mn dissolution loss.The average Li^(+)release capacity of 0.5AP-LMO//Ag system in simulated brine is 28.77 mg/(g h),which is 90.4%higher than LMO.Encouragingly,even in the more complex Zabuye real brine,0.5AP-LMO//Ag can still maintain excellent lithium extraction performance.These results indicate that the 0.5AP-LMO//Ag lithium-ion pump shows promising potential as a Li^(+)selective extraction system.

Seasonal Characteristics of Forecasting Uncertainties in Surface PM_(2.5)Concentration Associated with Forecast Lead Time over the Beijing-Tianjin-Hebei Region

Forecasting uncertainties among meteorological fields have long been recognized as the main limitation on the accuracy and predictability of air quality forecasts.However,the particular impact of meteorological forecasting uncertainties on air quality forecasts specific to different seasons is still not well known.In this study,a series of forecasts with different forecast lead times for January,April,July,and October of 2018 are conducted over the Beijing-Tianjin-Hebei(BTH)region and the impacts of meteorological forecasting uncertainties on surface PM_(2.5)concentration forecasts with each lead time are investigated.With increased lead time,the forecasted PM_(2.5)concentrations significantly change and demonstrate obvious seasonal variations.In general,the forecasting uncertainties in monthly mean surface PM_(2.5)concentrations in the BTH region due to lead time are the largest(80%)in spring,followed by autumn(~50%),summer(~40%),and winter(20%).In winter,the forecasting uncertainties in total surface PM_(2.5)mass due to lead time are mainly due to the uncertainties in PBL heights and hence the PBL mixing of anthropogenic primary particles.In spring,the forecasting uncertainties are mainly from the impacts of lead time on lower-tropospheric northwesterly winds,thereby further enhancing the condensation production of anthropogenic secondary particles by the long-range transport of natural dust.In summer,the forecasting uncertainties result mainly from the decrease in dry and wet deposition rates,which are associated with the reduction of near-surface wind speed and precipitation rate.In autumn,the forecasting uncertainties arise mainly from the change in the transport of remote natural dust and anthropogenic particles,which is associated with changes in the large-scale circulation.

Advantages of Short-term Personalized Vestibular Rehabilitation at Home Guided by Professional Therapist for Treatment of Decompensated Vestibular Vertigo

Objective Patients suffered a lot from decompensated vestibular vertigo.Pharmacotherapy and vestibular rehabilitation training have been proven to be effective in prompting vestibular compensation.Routine rehabilitation training is faced with the challenges of patients’compliance,completion,the average recuperation time and so on.This study is aimed to investigate advantages of short-term personalized vestibular rehabihitation at home guided by professional therapist.Methods A short-term personalized vestibular rehabilitation program(ST-PVR)was designed for patients with decompensated vestibular vertigo in this study.Results Patients experiencing the ST-PVR program showed significant improvement of Self-Rating Anxiety Scale(SAS),Dizziness Handicap Inventory(DHI),Activities-Specific Balance Confidence Scale(ABC)scores by the second follow-up(at 2nd week after treatment,P<0.05).However-improvement in the medication group occurred slightly later,DHI for 1 month and SAS for 2 months after treatment(P<0.05).Also,the improvement in the onset time of unilateral weakness(UW)at 2nd week after treatment in the personalized vestibular rehabilitation(PVR)group was faster than that in the medication group.Conclusion In general,the short-term PVR program showed great advantages by prompting vestibular compensation quickly and putting forward future direction for clinical treatment on decompensated vestibular vertigo.

Construction of porous disc-like lithium manganate for rapid and selective electrochemical lithium extraction from brine

In order to satisfy the growing global demand for lithium, selective extraction of lithium from brine has attracted extensive attention. LiMn_(2)O_(4)-based electrochemical lithium recovery system is one of the best choices for commercial applications because of its high selectivity and low energy consumption.However, the low ion diffusion coefficient of lithium manganate limits the further development of electrochemical lithium recovery system. In this work, a novel porous disc-like LiMn_(2)O_(4) was successfully synthesized for the first time via two-step annealing manganese(Ⅱ) precursors. The as-prepared LiMn_(2)O_(4) exhibits porous disc-like morphology, excellent crystallinity, high Li^(+)diffusion coefficient(average 7.6×10^(-9)cm^(2)·s^(-1)), high cycle stability(after 30 uninterrupted extraction and release cycles, the crystal structure hardly changed) and superior rate capacity(93.5% retention from 10-120 mA·g^(-1)). The porous structure and disc-like morphology further promote the contact between lithium ions and electrode materials. Therefore, the assembled electrochemical lithium extraction device with LiMn_(2)O_(4) as positive electrode and silver as negative electrode can realize the rapid and selective extraction of lithium in simulated brine(adsorption capacity of lithium can reach 4.85 mg·g^(-1) in 1 h). The mechanism of disc-like LiMn_(2)O_(4) in electrochemical lithium extraction was proposed based on the analysis of electrochemical characterization and quasi in situ XRD. This novel structure may further promote the practical application of electrochemical lithium extraction from brine.

Cytoplasmic FKBPs are involved in molting and metamorphosis through regulating the nuclear localization of EcR

Molting and metamorphosis are important physiological processes in insects that are tightly controlled by ecdysone receptor(EcR)through the 20-hydroxyecdysone(20E)signaling pathway.EcR is a steroid nuclear receptor(SR).Several FK506-binding proteins(FKBPs)have been identified from the mammal SR complex,and are thought to be involved in the subcellular trafficking of SR.However,their roles in insects are poorly understood.To explore whether FKBPs are involved in insect molting or metamorphosis,we injected an FKBP inhibitor(FK506)into a lepidopteran insect,Spodoptera litura,and found that molting was inhibited in 61.11%of the larvae,and that the time for larvae to pupate was significantly extended.A total of 10 FKBP genes were identified from the genome of s.litura and were clustered into 2 distinct groups,according to their subcellular localization,with FKBP13 and FKBP14 belonging to the endoplasmic reticulum(ER)group and with the other members belonging to the cytoplasmic(Cy)group.All the CyFKBPs were significantly upregulated in the prepupal or pupal stages,with the opposite being observed for the ER group members.FK506 completely blocked the transfer of EcR to the nucleus under 20E induction,and significantly downregulated the transcriptional expression of many 20E signaling genes.A similar phenomenon was observed after RNA interference of2 CyFKBPs(FKBP45 and FKBP12b),but not for FKBP13.Taken together,our data indicate that the cytoplasmic FKBPs,especially FKBP45 and FKBP12b,mediate the nuclear localization of EcR,thereby regulating the 20E signaling and ultimately affecting molting and metamorphosis in insects.

血浆网膜素1与2型糖尿病周围神经病变及其严重程度关系的研究

目的研究2型糖尿病(T2DM)患者血浆网膜素1(Omentin-1)水平与糖尿病周围神经病变(DPN)及其严重程度的关系。方法选取2017年3月-2017年9符合入选标准的T2DM患者122例,分为单纯T2DM患者67例(对照组)和合并DPN患者55例(DPN组)。收集患者临床资料,采用Logisitc回归模型分析DPN的危险因素,作受试者工作特征(ROC)曲线探索Omentin-1诊断DPN的效率,并应用线性回归分析Omentin-1与评估DPN严重程度的多伦多临床评分系统(TCSS)评分间关系。结果 (1) DPN组患者Omentin-1水平低于对照组(P <0.05);Omentin-1与胰岛素抵抗系数(HOMA-IR)(r=-0.375,P=0.000)及糖化血红蛋白(HbAlc)(r=-0.445,P=0.000)呈负相关。(2)多因素Logistic回归示:HbAlc[O^R=4.003(95%CI:1.016,10.776)]和HOMA-IR[(O^R=4.595(95%CI:1.709,12.324)]为DPN的危险因素;而Omentin-1[O^R=0.257(95%CI:0.112,0.589)]为DPN的保护因素。(3) ROC曲线示Omenitn-1诊断DPN的曲线下面积为0.713(95%CI:0.622,0.804),且当Omentin-1切值取18.8 ng/ml时,其诊断效率最高,敏感性为69.7%,特异性为71.8%。(4) Omentin-1与TCSS评分负相关(r=-0.606,P=0.000)。结论 Omentin-1是DPN的保护因素,在T2DM患者中可辅助DPN诊断及其严重程度的评估。

The Realistic Dilemma, Problem Tracking and Mitigating Strategies of Primary School Science Teachers’ Professional Happiness

The Science teachers in primary schools are the key group in developing science education, and they play a vital role in realizing the dream of strengthening the country through education. Their professional happiness deserves special attention. Whether this group is happy not only affects their own working conditions and quality of life, but also affects the work vitality of other teachers. Improving the professional happiness of science teachers in primary schools has become an important topic in the construction of teachers’ team in the new period. At present, the intensity of primary school science teachers’ own work is high, their non-own work is increasing, their physical and mental health is difficult to guarantee, and their professional happiness is reduced. The main causes of the problems are poor individual psychological quality, poor school management style and improper social cognitive evaluation. In order to solve this problem, we have explored strategies to improve the professional happiness of science teachers in primary schools through reshaping teachers’ work, democratic management of schools and national policy guarantee.

ERCP for patients who have undergone Billroth Ⅱ gastroenterostomy and Braun anastomosis

Endoscopic retrograde cholangiopancreatography(ERCP)is efficacious in patients who have undergone Billroth Ⅱ gastroenterostomies,but the success rate decreases in patients who also have experienced Braun anastomoses.There are currently no reports describing the preferred enterography route for cannulation in these patients.We first review the patient’s previous surgery records,which most often indicate that the efferent loop is at the greater curvature of the stomach.We recommend extending the duodenoscope along the greater curvature of the stomach and then advancing it through the"lower entrance"at the site of the gastrojejunal anastomosis,along the efferent loop,and through the"middle entrance"at the site of the Braun anastomosis to reach the papilla of Vater.Ten patients who had each undergone BillrothⅡgastroenterostomy and Braun anastomosis between January 2009 and December 2011 were included in our study.The overall success rate of enterography was 90% for the patients who had undergone BillrothⅡgastroenterostomy and Braun anastomosis,and the therapeutic success rate was 80%.We believe that this enterography route for ERCP is optimal for a patient who has had BillrothⅡgastroenterostomy and Braun anastomosis and helps to increase the success rate of the procedure.

Duct-to-duct biliary reconstruction after radical resection of Bismuth Ⅲ a hilar cholangiocarcinoma

At present, radical resection remains the only effective treatment for patients with hilar cholangiocarcinoma. The surgical approach for R0 resection of hilar cholangiocarcinoma is complex and diverse, but for the biliary reconstruction after resection, almost all surgeons use Roux-en-Y hepaticojejunostomy. A viable alternative to Roux-en-Y reconstruction after radical resection of hilar cholangiocarcinoma has not yet been proposed. We report a case of performing duct-to-duct biliary reconstruction after radical resection of Bismuth Ⅲa hilar cholangiocarcinoma. End-to-end anastomosis between the left hepatic duct and the distal common bile duct was used for the biliary reconstruction, and a singlelayer continuous suture was performed along the bile duct using 5-0 prolene. The patient was discharged favorably without biliary fistula 2 wk later. Evidence for tumor recurrence was not found after an 18 mo follow- up. Performing bile duct end-to-end anastomosis in hilar cholangiocarcinoma can simplify the complex digestive tract reconstruction process.

Entering the duodenal diverticulum:A method for cannulation of the intradiverticular papilla

Successful cannulation of the common bile duct may be difficult in patients in whom the papilla is located entirely within a diverticulum.In this study,we report successful biliary cannulation in three patients following intubation of the distal tip of the duodenoscope into the duodenal diverticulum and locating the major papilla.No complications occurred during the operation or during the postoperative period.This method didn't need second incubation an endoscope and might lower the burden of patients.So this skill is useful to deal with the papilla hidden inside the large diverticulum because of its safety and convenience.

Overexpression of connective tissue growth factor WISP-1 in Chinese primary rectal cancer patients

AIM: To clarify the expression change of Wnt-induced secreted protein-1 (WISP-1) in human rectal cancer and to determine whether it is correlated with invasion and metastasis of human rectal cancer. METHODS: Eighty-six paired samples of rectal cancer and surgically resected distant normal rectal tissue were collected and allocated into cancer group and control group respectively. WISP-1 mRNA was detected by relative quantitative real-time RT-PCR and WISP-1 protein was examined by immunohistochemical staining. RESULTS: WISP-1 gene overexpression was found in 65% (56/86) primary rectal cancers, 2-30 times that of the level in normal matched rectal tissues (P = 0.001). The mRNA expression level was correlated with Duke's staging, histological differentiation grade and lymph node status. The WISP-1 protein expression was in accordance with mRNA expression level. The positive degree of immunohistochemical staining in the cancer group (1.40 ± 0.35) was different from that in control group (1.04 ± 0.08, P < 0.001). Moreover, in cancer group the positive staining degree in high-level mRNA cancers (1.46 ± 0.37, n = 56) was higher than that in low-level mRNA (1.28 ± 0.28, n = 30, P = 0.018). CONCLUSION: Aberrant levels of WISP-1 expressionmay play a role in rectal tumorigenesis. WISP-1 may be used as a specific clinical diagnosis and prognosis marker in rectal cancer.

Total mesopancreas excision for pancreatic head cancer: analysis of 120 cases

Objective： To evaluate the feasibility and safety of total mesopancreas excision （TMpE） in the treatment of pancreatic head cancer. Methods： The clinical and pathological data of 120 patients with pancreatic head cancer who had undergone TMpE in our center from May 2010 to January 2014 were retrospectively analyzed. Results： The mean operative time was （275.0±50.2） min and the average intra-operative blood loss was （390.0±160.5） mL. Post-operative complications were reported in 45 patients, while no peri-operative death was noted. The specimen margins were measured in three dimensions, and 86 patients （71.6%） achieved R0 resection. Conclusions： TMpE is safe and feasible for pancreatic head cancer and is particularly helpful to increase the R0 resection rate.

Retrieval-balloon-assisted enterography in post-pancreaticoduodenectomy endoscopic retrograde cholangiopancreatography

This case reports an application of conventional duodenoscope in a post pancreaticoduodenectomy patient with the help of retrieval balloon assisted enterography.The 56-year-old woman had pancreaticoduodenectomy with Child reconstruction 9 mo ago because of pancreatic adenocarcinoma and now there are recurrent enlarged lymph nodes in the anastomotic stoma of hepaticojejunostomy.Considering the patient's late-stage cancer,a plastic stent was then successfully placed there to drainage.The main challenge in this case was the extremely long afferent loop and blind cannulation through the anastomotic stoma of hepaticojejunostomy.Retrieval balloon assisted enterography is very helpful for duodenoscope going through the reconstructed intestinal tract and for the cannulation.After two weeks,the patient remained free of painful symptoms and free of fever.Liver function improved well.Four months after the placement of stent,the patient died of cachexia without jaundice,fever and abdominal pain according to her daughter's statement.

Retrieval-balloon-assisted enterography for ERCP after Billroth Ⅱ gastroenterostomy and Braun anastomosis

AIM: To describe an optimal route to the Braun anastomosis including the use of retrieval-balloon-assisted enterography.METHODS: Patients who received a Billroth Ⅱ gastroenterostomy(n = 109) and a Billroth Ⅱ gastroenterostomy with Braun anastomosis(n = 20) between January 2009 and May 2013 were analyzed in this study. Endoscopic ret-rograde cholangiopancreatography(ERCP) was performed under fluoroscopic control using a total length of 120 cm oblique-viewing duodenoscope with a 3.7-mm diameter working channel. For this procedure, we used a triplelumen retrieval balloon catheter in which a 0.035-inch guidewire could be inserted into the "open-channel" guidewire lumen while the balloon could be simultaneously injected and inflated through the other 2 lumens.RESULTS: For the patients with Billroth Ⅱ gastroenterostomy and Braun anastomosis, successful access to the papilla was gained in 17 patients(85%) and there was therapeutic success in 16 patients(80%). One patient had afferent loop perforation, but postoperative bleeding did not occur. For Billroth Ⅱ gastroenterostomy, there was failure in accessing the papilla in 15 patients(13.8%). ERCP was unsuccessful because of tumor infiltration(6 patients), a long afferent loop(9 patients), and cannulation failure(4 patients). The papilla was successfully accessed in 94 patients(86.2%), and there was therapeutic success in 90 patients(82.6%). Afferent loop perforation did not occur in any of these patients. One patient had hemorrhage 2 h after ERCP, which was successfully managed with conservative treatment.CONCLUSION: Retrieval-balloon-assisted enterography along an optimal route may improve the ERCP success rate after Billroth Ⅱ gastroenterostomy and Braun anastomosis.

Surgical management of patients with bowel obstructions secondary to gastric cancer

AIM: To assess whole-body fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in the management of small bowel obstructions (SBOs) secondary to gastric cancer and its role in treatment strategies. METHODS: The medical records of all of the patients who were admitted for an intestinal obstruction after curative resection for gastric cancer were retrospectively reviewed. PET/CT was performed before a clinical treatment strategy was established for each patient. The patients were divided into 2 groups: patients with no evidence of a tumor recurrence and patients with evidence of a tumor recurrence. Tumor recurrences included a local recurrence, peritoneal carcinomatosis or distant metastases. The primary endpoint was the 1-year survival rate, and other variables included patient demographics, the length of hospital stay, complications, and mortality. RESULTS: The median time between a diagnosis of gastric cancer and the detection of a SBO was 1.4 years. Overall, 31 of 65 patients (47.7%) had evidence of a tumor recurrence on the PET/CT scan, which was the only factor that was associated with poor survival. Open and close surgery was the main type of surgical procedure reported for the patients with tumor recurrences. R0 resections were performed in 2 patients, including 1 who underwent combined adjacent organ resection. In the group with no evidence of a tumor recurrence on PET/CT, bowel resections were performed in 7 patients, adhesiolysis was performed in 7 patients, and a bypass was performed in 1 patient. The 1-year survival curves according to PET/CT evidence of a tumor recurrence vs no PET/CT evidence of a tumor recurrence were significantly different, and the 1-year survival rates were 8.8% vs 93.5%, respectively. There were no significant differences (P = 0.71) in the 1-year survival rates based on surgical vs nonsurgical management (0% with nonoperative treatment vs 20% after exploratory laparotomy). CONCLUSION: 18 F-FDG PET/CT can be used to identify the causes of bowel obstructions in patients with a history of gastric cancer, and this method is useful for planning the surgical management of these patients.

Modelling of an hydraulic excavator using simplifiedrefined instrumental variable(SRIV)algorithm

Instead of establishing mathematical hydraulic system models from physical laws usually done with the problems of complex modelling processes, low reliability and practicality caused by large uncertainties, a novel modelling method for a highly nonlinear system of a hydraulic excavator is presented. Based on the data collected in the excavator＇s arms driving experiments, a data-based excavator dynamic model using Simplified Refined Instrumental Variable （SRIV） identification and estimation algorithms is established. The validity of the proposed data-based model is indirectly demonstrated by the performance of computer simulation and the.real machine motion control exoeriments.

A stringent dual control system overseeing transcription and activity of the Cre recombinase for the liver-specific conditional gene knock-out mouse model

Liver cancer is one of the most threatening diseases in Chinese population. Just like in other tissues, tumor initiation and development in liver involve multiple steps of genetic and epigenetic alterations with several unknown details. However, unlike in other tissues, a tissue specific inducible Cre recombinase system that allows temporal and spatial deletion of a target DNA fragment is still not available for in vivo functional gene annotation in hepatocytes. In our pursuit to establish such a mouse model, we designed a dual inducible Cre transgene system and tested it in cultured cells. By combining a CCAAT/enhancer binding protein β （C/EBP β） promoter derived Tet-off expression system and the estrogen receptor （ER） mediated functional control, we show a desirable profile of both hepatocyte-specificity and regulability of the Cre expression in a series of critical assessments in the cell culture system, which provides confidence in continuation of our ongoing pursuit in mouse.

Impact of being overweight on the surgical outcomes of patients with gastric cancer: A meta-analysis

AIM: To investigate the effect of being overweight on the surgical results of patients with gastric cancer. METHODS: Comprehensive electronic searches of the PubMed, Web of Science, and Cochrane Library databases were conducted. Studies were identified that included patients with surgical complications from gastric cancer who were classified as normal weight [body mass index (BMI) < 25 kg/m 2 ] or overweight (BMI ≥ 25 kg/m 2 ). The operative time, retrieved lymph nodes, blood loss, and long-term survival were analyzed. A subgroup analysis was conducted based on whether patients received laparoscopic or open gastrectomy procedures. All statistical tests were performed using ReviewerManager 5.1.2 software. RESULTS: This meta-analysis included 23 studies with 20678 patients (15781 with BMI < 25 kg/m 2 ; 4897 with BMI ≥ 25 kg/m 2 ). Overweight patients had significantly increased operation times [MD: -29.14; 95%CI: -38.14-(-20.21); P < 0.00001], blood loss [MD: -194.58; 95%CI: -314.21-(-74.95); P = 0.001], complications (RR: 0.75; 95%CI: 0.66-0.85; P < 0.00001), anastomosis leakages (RR: 0.59; 95%CI: 0.42-0.82; P = 0.002), and pancreatic fistulas (RR: 0.486; 95%CI: 0.34-0.63; P < 0.00001), whereas lymph node retrieval was decreased significantly in the overweight group (MD: 1.69; 95%CI: 0.75-2.62; P < 0.0001). In addition, overweight patients had poorer long-term survival (RR: 1.14; 95%CI: 1.07-1.20; P < 0.0001). No significant difference was detected for the mortality and length of hospital stay. CONCLUSION: This meta-analysis demonstrates that a high BMI not only increases the surgical difficulty and complications but also impairs the long-term survival of patients with gastric cancer.

Application of single balloon enteroscopy-assisted therapeutic endoscopic retrograde cholangiopancreatography in patients after bilioenteric Roux-en-Y anastomosis: Experience of multi-disciplinary collaboration

BACKGROUND Bilioenteric Roux-en-Y anastomosis is one of the most complicated approaches for reconstructing the gastrointestinal tract, and endoscopic retrograde cholangiopancreatography (ERCP) is technically challenging in patients after bilioenteric Roux-en-Y anastomosis. The optimal endoscopic strategies for such cases remain unknown. AIM To explore the feasibility and effectiveness of single balloon enteroscopy-assisted (SBE-assisted) therapeutic ERCP in patients after bilioenteric Roux-en-Y anastomosis based on multi-disciplinary collaboration between endoscopists and surgeons as well as report the experience from China. METHODS This is a single center retrospective study. All of the SBE-assisted therapeutic ERCP procedures were performed by the collaboration between endoscopists and surgeons. The operation time, success rate, and complication rate were calculated. RESULTS Forty-six patients received a total of 64 SBE-assisted therapeutic ERCP procedures, with successful scope intubation in 60 (93.8%) cases and successful diagnosis in 59 (92.2%). All successfully diagnosed cases received successful therapy. None of the cases had perforation or bleeding during or after operation, and no post-ERCP pancreatitis occurred. CONCLUSION Based on multi-disciplinary collaboration, SBE-assisted therapeutic ERCP in patients after bilioenteric Roux-en-Y anastomosis is relatively safe and effective and has a high success rate.

Stability analysis of rib pillars in highwall mining under dynamic and static loads in open‑pit coal mine

The retained coal in the end slope of an open-pit mine can be mined by the highwall mining techniques.However,the instability mechanism of the reserved rib pillar under dynamic loads of mining haul trucks and static loads of the overlying strata is not clear,which restricts the safe and efcient application of highwall mining.In this study,the load-bearing model of the rib pillar in highwall mining was established,the cusp catastrophe theory and the safety coefcient of the rib pillar were considered,and the criterion equations of the rib pillar stability were proposed.Based on the limit equilibrium theory,the limit stress of the rib pillar was analyzed,and the calculation equations of plastic zone width of the rib pillar in highwall mining were obtained.Based on the Winkler foundation beam theory,the elastic foundation beam model composed of the rib pillar and roof under the highwall mining was established,and the calculation equations for the compression of the rib pillar under dynamic and static loads were developed.The results showed that with the increase of the rib pillar width,the total compression of the rib pillar under dynamic and static loads decreases nonlinearly,and the compression of the rib pillar caused by static loads of the overlying strata and trucks has a decisive role.Numerical simulation and theoretical calculation were also performed in this study.In the numerical simulation,the coal seam with a buried depth of 122 m and a thickness of 3 m is mined by highwall mining techniques.According to the established rib pillar instability model of the highwall mining system,it is found that when the mining opening width is 3 m,the reasonable width of the rib pillar is at least 1.3 m,and the safety factor of the rib pillar is 1.3.The numerical simulation results are in good agreement with the results of theoretical calculation,which verifes the feasibility of the theoretical analysis of the rib pillar stability.This research provides a reference for the stability analysis of rib pillars under highwall mining.