Distributed Optimal Formation Control for Unmanned Surface Vessels by a Regularized Game-Based Approach

Dear Editor,This letter explores optimal formation control for a network of unmanned surface vessels(USVs).By designing an individual objective function for each USV,the optimal formation problem is transformed into a noncooperative game.Under this game theoretic framework,the optimal formation is achieved by seeking the Nash equilibrium of the regularized game.A modular structure consisting of a distributed Nash equilibrium seeker and a regulator is proposed.

Research Progress and Prospects of Magnetic Nanomaterials

Nanomaterials are one of the research and development hotspots in the field of cutting-edge new materials,and also an important strategic emerging industry.Magnetic nanomaterials have broad application prospects in fields such as chemical engineering,new materials,electronic information,and biomedicine.This article introduces the application progress and preparation methods of magnetic nanomaterials,and puts forward suggestions for further optimizing the preparation process of magnetic nanomaterials and developing new magnetic materials with better performance.

A Top-down Method of Extraction Entity Relationship Triples and Obtaining Annotated Data

The extraction of entity relationship triples is very important to build a knowledge graph(KG),meanwhile,various entity relationship extraction algorithms are mostly based on data-driven,especially for the current popular deep learning algorithms.Therefore,obtaining a large number of accurate triples is the key to build a good KG as well as train a good entity relationship extraction algorithm.Because of business requirements,this KG’s application field is determined and the experts’opinions also must be satisfied.Considering these factors we adopt the top-down method which refers to determining the data schema firstly,then filling the specific data according to the schema.The design of data schema is the top-level design of KG,and determining the data schema according to the characteristics of KG is equivalent to determining the scope of data’s collection and the mode of data’s organization.This method is generally suitable for the construction of domain KG.This article proposes a fast and efficient method to extract the topdown type KG’s triples in social media with the help of structured data in the information box on the right side of the related encyclopedia webpage.At the same time,based on the obtained triples,a data labeling method is proposed to obtain sufficiently high-quality training data,using in various Natural Language Processing(NLP)information extraction algorithms’training.

Future Event Prediction Based on Temporal Knowledge Graph Embedding

Accurate prediction of future events brings great benefits and reduces losses for society in many domains,such as civil unrest,pandemics,and crimes.Knowledge graph is a general language for describing and modeling complex systems.Different types of events continually occur,which are often related to historical and concurrent events.In this paper,we formalize the future event prediction as a temporal knowledge graph reasoning problem.Most existing studies either conduct reasoning on static knowledge graphs or assume knowledges graphs of all timestamps are available during the training process.As a result,they cannot effectively reason over temporal knowledge graphs and predict events happening in the future.To address this problem,some recent works learn to infer future events based on historical eventbased temporal knowledge graphs.However,these methods do not comprehensively consider the latent patterns and influences behind historical events and concurrent events simultaneously.This paper proposes a new graph representation learning model,namely Recurrent Event Graph ATtention Network(RE-GAT),based on a novel historical and concurrent events attention-aware mechanism by modeling the event knowledge graph sequence recurrently.More specifically,our RE-GAT uses an attention-based historical events embedding module to encode past events,and employs an attention-based concurrent events embedding module to model the associations of events at the same timestamp.A translation-based decoder module and a learning objective are developed to optimize the embeddings of entities and relations.We evaluate our proposed method on four benchmark datasets.Extensive experimental results demonstrate the superiority of our RE-GAT model comparing to various base-lines,which proves that our method can more accurately predict what events are going to happen.

Effect of preoperative inspiratory muscle training on postoperative outcomes in patients undergoing cardiac surgery:A systematic review and meta-analysis

BACKGROUND Cardiovascular disease is the most prevalent disease worldwide and places a great burden on the health and economic welfare of patients.Cardiac surgery is an important way to treat cardiovascular disease,but it can prolong mechanical ventilation time,intensive care unit(ICU)stay,and postoperative hospitalization for patients.Previous studies have demonstrated that preoperative inspiratory muscle training could decrease the incidence of postoperative pulmonary complications.AIM To explore the effect of preoperative inspiratory muscle training on mechanical ventilation time,length of ICU stay,and duration of postoperative hospitalization after cardiac surgery.METHODS A literature search of PubMed,Web of Science,Cochrane Library,EMBASE,China National Knowledge Infrastructure,WanFang,and the China Science and Technology journal VIP database was performed on April 13,2022.The data was independently extracted by two authors.The inclusion criteria were:(1)Randomized controlled trial;(2)Accessible as a full paper;(3)Patients who received cardiac surgery;(4)Preoperative inspiratory muscle training was implemented in these patients;(5)The study reported at least one of the following:Mechanical ventilation time,length of ICU stay,and/or duration of postoperative hospitalization;and(6)In English language.RESULTS We analyzed six randomized controlled trials with a total of 925 participants.The pooled mean difference of mechanical ventilation time was-0.45 h[95%confidence interval(CI):-1.59-0.69],which was not statistically significant between the intervention group and the control group.The pooled mean difference of length of ICU stay was 0.44 h(95%CI:-0.58-1.45).The pooled mean difference of postoperative hospitalization was-1.77 d in the intervention group vs the control group[95%CI:-2.41-(-1.12)].CONCLUSION Preoperative inspiratory muscle training may decrease the duration of postoperative hospitalization for patients undergoing cardiac surgery.More high-quality studies are needed to confirm our conclusion.

完全机器人腹腔镜腹膜后入路活体供肾切取术的临床应用

目的探讨机器人腹腔镜腹膜后入路活体供肾切取的手术技术及安全性,总结临床经验。方法分析该院2017年1月所实施的3例机器人活体供肾切取术,供受体均为母子关系,供体年龄47~49岁,受体年龄23~29岁,其中取左肾2例,右肾1例,术前供体各项检查及伦理审批完全符合捐献条件,术前血管成像未发现血管变异,1例术中发现一支副肾动脉。结果 3例患者顺利完成供肾切取术,未行中转开放。术后未发生手术相关并发症,手术时间分别为115.0、120.0和140.0 min;术中出血量50、85及110 ml;热缺血时间2.0~4.0 min;3例患者均在术后第3天拨除引流管,术后第5天出院。移植肾均在血流开放后2.0 min内泌尿,术后1周内移植肾功能均恢复正常。结论采用经腹膜后入路行机器人活体供肾切取术是安全有效的,供体术后恢复快,对供肾也无不利影响,但高昂的手术费用制约了其广泛的临床应用。

射频消融辅助肝切除治疗原发性肝癌的临床应用

目的探讨射频消融辅助开腹肝切除治疗原发性肝癌的安全性和临床疗效。方法收集2013年6月-2015年12月南昌大学第一附属医院接受肝癌切除术的52例肝癌患者的临床资料进行回顾性分析。观察组采用射频消融联合肝切除术治疗,对照组采用传统开腹肝切除术治疗,每组患者26例。比较两组患者手术时间、术中入肝血流阻断情况、术中出血量、肝癌完全切除率、术后并发症发生率、术后3、6及12个月肿瘤复发情况。结果两组患者均顺利完成R0切除。两组患者手术时间比较差异无统计学意义(P>0.05)。观察组术中出血量、术中入肝血流阻断例数及术后并发症与对照组相比,差异有统计学意义(P<0.05),观察组均低于对照组。术后3、6及12个月两组患者均未见复发转移。结论相比传统的肝癌切除术,射频消融联合治疗在不影响治疗效果的同时可有效减少术中入肝血流的阻断次数,降低术中出血量和术后并发症的发生率,是一种安全有效的治疗方案。

有机合成协同思政教育的课程体系构建探索

为切实推进有机合成课程教学与思政教育同向同行协同育人,从凝练双重育人功能的课程教学体系、深化课程教学中的创新思维、辩证思维教育、增强绿色化学发展与环境和谐共生意识、深挖思政教育与有机合成课程的交融点等方面探索了思政教育融于有机合成课程教学体系的具体实践措施,构建了有机合成专业课程思政教育体系,系统化、针对性落实立德树人根本任务。

两性离子聚合物的制备性能及在抗污染分离膜中应用的研究现状

两性离子聚合物分子链中含有等量阴、阳离子基团,呈现"反聚电解质效应",具有良好的热、化学稳定性,亲水性,生物相容性以及优异的抗污染等性能,被广泛应用于石油化工、医疗器械、分离材料等领域。文中在简要介绍两性离子聚合物的制备方法及性能的基础上,着重阐述了近年来为提高分离膜抗污染性引入两性离子聚合物的方法,包括表面接枝、表面偏析、化学气相沉积、仿生黏附及界面聚合等,并对今后研究方向提出建议。

Xiaotan Sanjie decoction attenuates tumor angiogenesis by manipulating Notch-1-regulated proliferation of gastric cancer stem-like cells

AIM: To determine the underlying mechanisms of action and influence of Xiaotan Sanjie(XTSJ) decoction on gastric cancer stem-like cells(GCSCs). METHODS: The gastric cancer cell line MKN-45 line was selected and sorted by FACS using the cancer stem cell marker CD44; the stemness of these cells was checked in our previous study. In an in vitro study, the expression of Notch-1, Hes1, Vascular endothelial growth factor(VEGF), and Ki-67 in both CD44-positive gastric cancer stem-like cells(GCSCs) and CD44-negative cells was measured by Western blot. The effect of XTSJ serum on cell viability and on the above markers was measured by MTT assay and Western blot, respectively. In an in vivo study, the ability to induce angiogenesis and maintenance of GCSCs in CD44-positive-MKN-45- and CD44-negative-engrafted mice were detected by immunohistochemical staining using markers for CD34 and CD44, respectively. The role of XTSJ decoction in regulating the expression of Notch-1, Hes1, VEGF and Ki-67 was measured by Western blot and real-time polymerase chain reaction.RESULTS: CD44+ GCSCs showed more cell proliferation and VEGF secretion than CD44-negative cells in vitro, which were accompanied by the high expression of Notch-1 and Hes1 and positively associated with tumor growth(GCSCs vs CD44-negative cells, 2.72 ± 0.25 vs 1.46 ± 0.16, P < 0.05) and microvessel density(MVD)(GCSCs vs CD44-negative cells, 8.15 ± 0.42 vs 3.83 ± 0.49, P < 0.001) in vivo. XTSJ decoction inhibited the viability of both cell types in a dose-dependent manner in vitro. Specifically, a significant difference in the medium-(82.87% ± 6.53%) and high-dose XTSJ groups(77.43% ± 7.34%) was detected at 24 h in the CD44+ GCSCs group compared with the saline group(95.42% ± 5.76%) and the low-dose XTSJ group(90.74% ± 6.57%)(P < 0.05). However, the efficacy of XTSJ decoction was reduced in the CD44- groups; significant differences were only detected in the high-dose XTSJ group at 48 h(78.57% ± 6.94%) and 72 h(72.12% ± 7.68%) when compared with the other CD44- groups(P < 0.05). Notably, these differences were highly consistent with the Notch-1, Hes1, VEGF and Ki-67 expression in these cells. Similarly, in vivo, XTSJ decoction inhibited tumor growth in a dose-dependent manner. A significant difference was observed in the medium(1.76 ± 0.15) and high-dose XTSJ(1.33 ± 0.081) groups compared with the GCSCs control group(2.72 ± 0.25) and the low-dose XTSJ group(2.51 ± 0.25)(P < 0.05). We also detected a remarkable decrease of MVD in the medium-(7.10 ± 0.60) and high-dose XTSJ(5.99 ± 0.47) groups compared with the GCSC control group(8.15 ± 0.42) and the low-dose XTSJ group(8.14 ± 0.46)(P < 0.05). Additionally, CD44 expression was decreased in these groups [medium-(4.43 ± 0.45) and high-dose XTSJ groups(3.56 ± 0.31) vs the GCSC control(5.96 ± 0.46) and low dose XTSJ groups(5.91 ± 0.38)](P < 0.05). The significant differences in Notch-1, Hes1, VEGF and Ki-67 expression highly mirrored the results of XTSJ decoction in inhibiting tumor growth, MVD and CD44 expression.CONCLUSION: Notch-1 may play an important role in regulating the proliferation of GCSCs; XTSJ decoction could attenuate tumor angiogenesis, at least partially, by inhibiting Notch-1.

Xiaotan Sanjie decoction inhibits interleukin-8-induced metastatic potency in gastric cancer

AIM:To investigate the interaction between Xiaotan Sanjie(XTSJ) decoction and interleukin-8(IL-8) and its effect on adhesion,migration and invasion of SGC-7901 gastric cancer cells.METHODS:SGC-7901 gastric cancer cells were exposed to serum containing XTSJ decoction and/orIL-8(1 ng/m L).SGC-7901 cell adhesion to fibronectin,an extracellular matrix component,was detected using the Cell Counting Kit-8.Migration and invasion abilities of SGC-7901 cells were detected by scratch wound and Transwell chamber assays.Then,protein(immunofluorescence and Western blot) and m RNA levels(quantitative polymerase chain reaction) of cluster of differentiation 44(CD44),a cell adhesion molecule,were measured in 72-h-cultured SGC-7901 cells.RESULTS:Cell adhesion was promoted by IL-8(P = 0.001),but was inhibited by XTSJ decoction(P = 0.0001).Similarly,IL-8 promoted SGC-7901 cell invasion(P = 0.003),and XTSJ decoction inhibited cell invasion(P = 0.001).IL-8 induced SGC-7901 cell migration,but this was inhibited by XTSJ decoction.IL-8 up-regulated CD44 protein(P = 0.028) and m RNA expression(P = 0.002),whereas XTSJ decoction inhibited CD44 protein expression(P = 0.0001),but not m RNA expression(P = 0.275).An interaction between XTSJ decoction and IL-8 was confirmed in the invasion(P = 0.001) and CD44 m RNA expression of SGC-7901 cells(P = 0.010),but not in cell adhesion(P = 0.051).CONCLUSION:XTSJ decoction may inhibit adhesion,migration and invasion of gastric cancer cells,which is partly associated with down-regulation of IL-8.

Effectiveness and safety of herbal medicines in the treatment of irritable bowel syndrome:A systematic review

AIM:To explore the efficacy and safety of herbal medicines (HM) in the treatment of irritable bowel syndrome (IBS). METHODS: A computer-based as well as manual literature search was performed. We reviewed randomized controlled trials on the treatment of IBS with and without HM. RESULTS: A total of 22 studies with 25 HMs met the inclusion criteria. Four of these studies were of good quality, while the remaining 18 studies involving 17 Chinese herbal medicine (CHM) formulas were of poor quality. Eight of these reports using 9 HMs showed global improvement of IBS symptoms, 4 studies with 3 HMs were efficacious in diarrhea-predominant IBS, and 2 studies with 2 HMs showed improvement in constipation- predominant IBS. Out of a total of 1279 patients, 15 adverse events in 47 subjects were reported with HM. No serious adverse events or abnormal laboratory tests were observed. The incidence of the adverse events was low (2.97%; 95% CI: 2.04%-3.90%). CONCLUSION: Herbal medicines have therapeutic benefit in IBS, and adverse events are seldom reported in literature. Nevertheless, herbal medicines should be used with caution. It is necessary to conduct rigorous, well-designed clinical trials to evaluate their effectiveness and safety in the treatment of IBS.

Traditional surgical planning of liver surgery is modified by 3D interactive quantitative surgical planning approach： a single-center experience with 305 patients

BACKGROUND： Decision making and surgical planning are to achieve the precise balance of maximal removal of target lesion, maximal sparing of functional liver remnant volume, and minimal surgical invasiveness and therefore, crucial in liver surgery. The aim of this prospective study was to validate the accuracy and predictability of 3D interactive quantitative surgical planning approach （IQSP）, and to evaluate the impact of IQSP on traditional surgical plans based on 2D images. METHODS： A total of 305 consecutive patients undergoing hepatectomy were included in this study. Surgical plans were created by traditional 2D approach using picture archiving and communication system （PACS） and 3D approach using IQSP respectively by two groups of physicians who did not know the surgical plans of the other group. The two surgical plans were submitted to the chief surgeon for selection before operation. The specimens were weighed. The two surgical plans were compared and analyzed retrospectively based on the operation results. RESULTS： The two surgical plans were successfully developed in all 305 patients and all the 3D IQSP surgical plans were selected as the final decision. Total 278 patients successfully underwent surgery, including 147 uncomplex hepatectomy and 131 complex hepatectomy. Twenty-seven patients were withdrawn from hepatectomy. In the uncomplex group, the two surgical plans were the same in all 147 patients and no statistically significant difference was found among 2D calcu- lated resection volume （2D-RV）, 3D IQSP calculated resection volume （IQSP-RV） and the specimen volume. In the complex group, the two surgical plans were different in 49 patients （49/131, 37.4%）. According to the significance of differences, the 49 different patients were classified into three grades. No statistically significant difference was found between IQSP-RV and specimen volume. The coincidence rate of territory analy- sis of IQSP with operation was 92.1% （93/101） for 101 patients of anatomic hepatectomy. CONCLUSIONS： The accuracy and predictability of 3D IQSP were validated. Compared with traditional surgical planning, 3D IQSP can provide more quantitative information of anatomic structure. With the assistance of 3D IQSP, traditional surgical plans were modified to be more radical and safe.

Xiaotan Tongfu granules contribute to the prevention of stress ulcers

AIM:To investigate the efficacy and potential mechanism of Xiaotan Tongfu granules(XTTF)in stress ulcers.METHODS:One hundred sixty rats were randomly divided into 4 groups(n=10)as follows:the model group(MP group),the control group(CP group),the ranitidine group(RP group)and the XTTF granule group(XP group).Rats in the MP group received no drugs,rats in the CP group received 0.2 mL of a 0.9%sodium chloride solution via oral gavage,and rats in the RP and XP groups received the same volume of ranitidine(50 mg/kg)or XTTF granule(4.9 g/kg).The cold-restraint stress model was applied to induce stress ulcers after 7 consecutive days of drug administration.Afterwards,rats were sacrificed at 0,3,6 and24 h.Gastric pH was measured by a precise pH meter;gastric emptying rate(GER)was measured by using a methylcellulose test meal;myeloperoxidase activity(MPO),macrophage migration inhibitory factor(MIF),proliferating cell nuclear antigen(PCNA),and heat shock protein 70(HSP70)were measured by immunohistochemical staining;and mucosal cell apoptosis was measured by transferase dUTP nick end labeling.RESULTS:In the cold-restraint stress model,the development of stress ulcers peaked at 3 h and basically regressed after 24 h.Gastric lesions were significantly different in the RP and XP groups at each time point.Interestingly,although this index was much lower in the RP group than in the XP group immediately following stress induction(7.00±1.10 vs 10.00±1.79,P<0.05.Concerning gastric pH,between the RP and XP groups,we detected a statistically significant difference immediately after stress induction(0 h:4.56±0.47 vs 3.34±0.28,P<0.05)but not at any of the subsequent time points.For GER,compared to the RP group,GER was remarkably elevated in the XP group because a statistically significant difference was detected(3 h:46.84±2.70 vs 61.16±5.12,P<0.05;6 h:60.96±6.71 vs 73.41±6.16,P<0.05;24 h:77.47±3.17 vs 91.31±4.34,P<0.05).With respect to MPO and MIF,comparisons between the RP and XP groups revealed statistically significant differences at 3 h(MPO:18.94±1.20 vs 13.51±0.89,P<0.05;MIF:150.67±9.85 vs 122.17±5.67,P<0.05)and 6 h(MPO:13.22±1.54 vs 8.83±0.65,P<0.05;MIF:135.50±9.46 vs 109.83±6.40,P<0.05).With regard to HSP70,HSP70 expression was significantly increased in the RP and XP groups at 3 and 6 h compared to the MP and CP groups.In addition,comparing the RP and XP groups also showed statistically significant differences at 3 and 6 h.The expression of PCNA was higher in the RP and XP groups 3 h after stress induction.Between these two groups,small but statistically significant differences were observed at all of the time points(3 h:69.50±21.52 vs 79.33±15.68,P<0.05;6 h:107.83±4.40 vs 121.33±5.71,P<0.05;24 h:125.33±5.65 vs 128.50±14.49,P<0.05)except 0 h.With regard to apoptosis,the apoptotic activity in the RP and XP groups was significantly different from that in the MP and CP groups.The XP group exhibited a higher inhibition of cell apoptosis than the RP group at3 h(232.58±24.51 vs 174.46±10.35,P<0.05)and6 h(164.74±18.31 vs 117.71±12.08,P<0.05).CONCLUSION:The Xiaotan Tongfu granule was demonstrated to be similar to ranitidine in preventing stress ulcers.It exhibited multiple underlying mechanisms and deserves further study.

Transplantation of human umbilical cord blood mesenchymal stem cells to treat a rat model of traumatic brain injury

In the present study, human umbilical cord blood mesenchymal stem cells were injected into a rat model of traumatic brain injury via the tail vein. Results showed that 5-bromodeoxyuridine-labeled cells aggregated around the injury site, surviving up to 4 weeks post-transplantation. In addition, transplantation-related death did not occur, and neurological functions significantly improved. Histological detection revealed attenuated pathological injury in rat brain tissues following human umbilical cord blood mesenchymal stem cell transplantation. In addition, the number of apoptotic cells decreased. Immunohistochemistry and in situ hybridization showed increased expression of brain-derived neurotrophic factor, nerve growth factor, basic fibroblast growth factor, and vascular endothelial growth factor, along with increased microvessel density in surrounding areas of brain injury. Results demonstrated migration of transplanted human umbilical cord blood mesenchymal stem cells into the lesioned boundary zone of rats, as well as increased angiogenesis and expression of related neurotrophic factors in the lesioned boundary zone.

Highly reversible lead-carbon battery anode with lead grafting on thecarbon surface

A novel C/Pb composite has been successfully prepared by electmless plating to reduce the hydrogenevolution and achieve the high reversibility of the anode of lead-carbon battery （LCB）. The depositedlead on the surface of C/Pb composite was found to be uniform and adherent to carbon surface. Becauselead has been stuck on the surface of C/Pb composite, the embedded structure suppresses the hydrogenevolution of lead-carbon anode and strengthens the connection between carbon additive and sponge lead.Compared with the blank anode, the lead-carbon anode with C/Pb composite displays excellent charge-discharge reversibility, which is attributed to the good connection between carbon additives and leadthat has been stuck on the surface of C/Pb composite during the preparation process. The addition of CIPb composite maintains a solid anode structure with high specific surface area and power volume, andthereby, it plays a significant role in the highly reversible lead-carbon anode.

Mini-invasive vs open resection of colorectal cancer and liver metastases: A meta-analysis

BACKGROUND The safety and feasibility of the simultaneous resection of primary colorectal cancer (CRC) and synchronous colorectal liver metastases (SCRLM) have been demonstrated in some studies. Combined resection is expected to be the optimal strategy for patients with CRC and SCRLM. However, traditional laparotomy is traumatic, and the treatment outcome of minimally invasive surgery (MIS) is still obscure. AIM To compare the treatment outcomes of MIS and open surgery (OS) for the simultaneous resection of CRC and SCRLM. METHODS A systematic search through December 22, 2018 was conducted in electronic databases (PubMed, EMBASE, Web of Science, and Cochrane Library). All studies comparing the clinical outcomes of MIS and OS for patients with CRC and SCRLM were included by eligibility criteria. The meta-analysis was performed using Review Manager Software. The quality of the pooled study was assessed using the Newcastle-Ottawa scale. The publication bias was evaluated by a funnel plot and the Begg’s and Egger’s tests. Fixed- and random-effects models were applied according to heterogeneity. RESULTS Ten retrospective cohort studies involving 502 patients (216 patients in the MIS group and 286 patients in the OS group) were included in this study. MIS was associated with less intraoperative blood loss [weighted mean difference (WMD)=-130.09, 95% confidence interval (CI):-210.95 to -49.23, P = 0.002] and blood transfusion [odds ratio (OR)= 0.53, 95%CI: 0.29 to 0.95, P = 0.03], faster recovery of intestinal function (WMD =-0.88 d, 95%CI:-1.58 to -0.19, P = 0.01) and diet (WMD =-1.54 d, 95%CI:-2.30 to -0.78, P < 0.0001), shorter length of postoperative hospital stay (WMD =-4.06 d, 95%CI:-5.95 to -2.18, P < 0.0001), and lower rates of surgical complications (OR = 0.60, 95%CI: 0.37 to 0.99, P = 0.04). However, the operation time, rates and severity of overall complications, and rates of general complications showed no significant differences between the MIS and OS groups. Moreover, the overall survival and disease-free survival after MIS were equivalent to those after OS. CONCLUSION Considering the studies included in this meta-analysis, MIS is a safe and effective alternative technique for the simultaneous resection of CRC and SCRLM. Compared with OS, MIS has less intraoperative blood loss and blood transfusion and quicker postoperative recovery. Furthermore, the two groups show equivalent long-term outcomes.

A Novel Orthogonal LoRa Multiple Access Algorithm for Satellite Internet of Things

In recent years,LoRa has been extensively researched in the satellite Internet of Things(IoT).However,the multiple access technology of LoRa is still one of the bottlenecks of satellite IoT.To improve the multiple access performance of LoRa satellite IoT,based on the orthogonality of LoRa symbols in the fractional domain,this paper proposes a low complexity Orthogonal LoRa Multiple Access(OLMA)algorithm for multiple LoRa users occupying the same frequency bandwidth.The algorithm introduces the address code to divide the fractional bandwidth into multiple parts,and the OLMA users with different address codes occupy different parts to transmit the information code,thus avoiding mutual interference caused by collisions in the same frequency bandwidth.The multiple access capability of OLMA can be flexibly configured only by simply adjusting the length of the address code according to the actual application requirements of data transmission.Theoretical analysis and simulation results show that the OLMA algorithm can greatly improve the multiple access capability and the total transmission bit rate of LoRa IoT without changing the existing LoRa modulation parameters and process.

In vitro and in vivo evaluations of Mg-Zn-Gd alloy membrane on guided bone regeneration for rabbit calvarial defect

To develop a biodegradable membrane with guided bone regeneration(GBR),a Mg-2.0Zn-1.0Gd alloy(wt.%,MZG)membrane with Ca-P coating was designed and fabricated in this study.The microstructure,hydrophilicity,in vitro degradation,cytotoxicity,antibacterial effect and in vivo regenerative performance for the membrane with and without Ca-P coating were evaluated.After coating,the membrane exhibited an enhance hydrophilicity and corrosion resistance,showed good in vitro cytocompatibility upon MC3T3E-1 cells,and exhibited excellent antibacterial effect against E.coli,Staphylococcus epidermis and Staphylococcus aureus,simultaneously.In vivo experiment using the rabbit calvarial defect model confirmed that Ca-P coated MZG membrane underwent progressive degradation without inflammatory reaction and significantly improved the new bone formation at both 1.5 and 3 months after the surgery.All the results strongly indicate that MZG with Ca-P coating have great potential for clinical application as GBR membranes.

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.