Present situation and prospect of immunotherapy for unresectable locally advanced esophageal cancer during peri-radiotherapy

Four major studies(Checkmate577,Keynote-590,Checkmate649 and Attraction-4)of locally advanced esophageal cancer published in 2020 have established the importance of immunotherapy,represented by anti-programmed death protein(PD)-1 in postoperative adjuvant treatment and advanced first-line treatment of locally advanced or advanced esophageal cancer and esophagogastric junction cancer,from the aspects of proof of concept,long-term survival,overall survival rate and progression-free survival.For unresectable or inoperable nonmetastatic esophageal cancer,concurrent radiotherapy and chemotherapy is the standard treatment recommended by various guidelines.Because its curative effect is still not ideal,it is necessary to explore radical radiotherapy and chemotherapy in the future,and it is considered to be promising to combine them with immunotherapeutic drugs such as anti-PD-1.This paper mainly discusses how to combine radical concurrent radiotherapy and chemotherapy with immunotherapy for unresectable local advanced esophageal cancer.

Improving the utility of locally differentially private protocols for longitudinal and multidimensional frequency estimates

This paper investigates the problem of collecting multidimensional data throughout time(i.e.,longitudinal studies)for the fundamental task of frequency estimation under Local Differential Privacy(LDP)guarantees.Contrary to frequency estimation of a single attribute,the multidimensional aspect demands particular attention to the privacy budget.Besides,when collecting user statistics longitudinally,privacy progressively degrades.Indeed,the“multiple”settings in combination(i.e.,many attributes and several collections throughout time)impose several challenges,for which this paper proposes the first solution for frequency estimates under LDP.To tackle these issues,we extend the analysis of three state-of-the-art LDP protocols(Generalized Randomized Response–GRR,Optimized Unary Encoding–OUE,and Symmetric Unary Encoding–SUE)for both longitudinal and multidimensional data collections.While the known literature uses OUE and SUE for two rounds of sanitization(a.k.a.memoization),i.e.,L-OUE and L-SUE,respectively,we analytically and experimentally show that starting with OUE and then with SUE provides higher data utility(i.e.,L-OSUE).Also,for attributes with small domain sizes,we propose Longitudinal GRR(L-GRR),which provides higher utility than the other protocols based on unary encoding.Last,we also propose a new solution named Adaptive LDP for LOngitudinal and Multidimensional FREquency Estimates(ALLOMFREE),which randomly samples a single attribute to be sent with the whole privacy budget and adaptively selects the optimal protocol,i.e.,either L-GRR or L-OSUE.As shown in the results,ALLOMFREE consistently and considerably outperforms the state-of-the-art L-SUE and L-OUE protocols in the quality of the frequency estimates.

Epidemiology and prognostic nomogram for locally advanced gastric signet ring cell carcinoma:A population-based study

BACKGROUND Gastric signet ring cell carcinoma(GSRC)represents a specific subtype of gastric cancer renowned for its contentious epidemiological features,treatment principles,and prognostic factors.AIM To investigate the epidemiology of GSRC and establish an improved model for predicting the prognosis of patients with locally advanced GSRC(LAGSRC)after surgery.METHODS The annual rates of GSRC incidence and mortality,covering the years 1975 to 2019,were extracted from the Surveillance,Epidemiology,and End Results(SEER)database to explore the temporal trends in both disease incidence and mortality rates using Joinpoint software.The clinical data of 3793 postoperative LAGSRC patients were collected from the SEER database for the analysis of survival rates.The Cox regression model was used to explore the independent prognostic factors for overall survival(OS).The risk factors extracted were used to establish a prognostic nomogram.RESULTS The overall incidence of GSRC increased dramatically between 1975 and 1998,followed by a significant downward trend in incidence after 1998.In recent years,there has been a similarly optimistic trend in GSRC mortality rates.The trend in GSRC showed discrepancies based on age and sex.Receiver operating characteristic curves,calibration curves,and decision curve analysis for 1-year,3-year,and 5-year OS demonstrated the high discriminative ability and clinical utility of this nomogram.The area under the curve indicated that the performance of the new model outperformed that of the pathological staging system.CONCLUSION The model we established can aid clinicians in the early prognostication of LAGSRC patients,resulting in improved clinical outcomes by modifying management strategies and patient health care.

Hsa-miR-483-5p/mRNA network that regulates chemotherapy resistance in locally advanced rectal cancer identified through plasma exosome transcriptomics

BACKGROUND Chemoresistance is the primary contributor to distant metastasis in the context of neoadjuvant chemoradiotherapy(nCRT)for rectal cancer.However,the underlying mechanisms remain elusive.AIM To detect the differential expression profiles of plasma exosomal microRNAs(miRNAs)in poor and good responders and explore the potential mechanisms of chemoresistance.METHODS In this study,the profiles of plasma exosomal miRNAs were compared in two dimensions according to treatment responses(poor/good responders)and treatment courses(pre/post-nCRT)using RNA sequencing.RESULTS Exosome hsa-miR-483-5p was up-regulated in good responders post-nCRT.Bioinformatics analysis revealed that the target genes of hsa-miR-483-5p were mainly enriched in tumor-specific pathways,such as the MAPK signaling pathway,EGFR tyrosine kinase inhibitor resistance,Toll-like receptor signaling pathway,VEGF signaling pathway,and mTOR signaling pathway.Further analysis indicated that MAPK3,RAX2,and RNF165 were associated with inferior recurrence-free survival in patients with rectal cancer,and the profiles of MAPK3,TSPYL5,and ZNF-417 were correlated with tumor stage.In addition,the expression profiles of MAPK3,RNF165,and ZNF417 were negatively correlated with inhibitory concentration 50 values.Accordingly,an hsa-miR-483-5p/MAPK3/RNF 165/ZNF417 network was constructed.CONCLUSION This study provides insights into the mechanism of chemoresistance in terms of exosomal miRNAs.However,further research is required within the framework of our established miRNA-mRNA network.

Prediction of pathological complete response and prognosis in locally advanced rectal cancer

BACKGROUND Colorectal cancer is currently the third most common malignant tumor and the second leading cause of cancer-related death worldwide.Neoadjuvant chemoradiotherapy(nCRT)is standard for locally advanced rectal cancer(LARC).Except for pathological examination after resection,it is not known exactly whether LARC patients have achieved pathological complete response(pCR)before surgery.To date,there are no clear clinical indicators that can predict the efficacy of nCRT and patient outcomes.AIM To investigate the indicators that can predict pCR and long-term outcomes following nCRT in patients with LARC.METHODS Clinical data of 128 LARC patients admitted to our hospital between September 2013 and November 2022 were retrospectively analyzed.Patients were categorized into pCR and non-pCR groups.Univariate analysis(using the χ^(2) test or Fisher’s exact test)and logistic multivariate regression analysis were used to study clinical predictors affecting pCR.The 5-year disease-free survival(DFS)and overall survival(OS)rates were calculated using Kaplan-Meier analysis,and differences in survival curves were assessed with the log-rank test.RESULTS Univariate analysis showed that pretreatment carcinoembryonic antigen(CEA)level,lymphocyte-monocyte ratio(LMR),time interval between neoadjuvant therapy completion and total mesorectal excision,and tumor size were correlated with pCR.Multivariate results showed that CEA≤5 ng/mL(P=0.039),LMR>2.73(P=0.023),and time interval>10 wk(P=0.039)were independent predictors for pCR.Survival analysis demonstrated that patients in the pCR group had significantly higher 5-year DFS rates(94.7%vs 59.7%,P=0.002)and 5-year OS rates(95.8%vs 80.1%,P=0.019)compared to the non-pCR group.Tumor deposits(TDs)were significantly correlated with shorter DFS(P=0.002)and OS(P<0.001).CONCLUSION Pretreatment CEA,LMR,and time interval contribute to predicting nCRT efficacy in LARC patients.Achieving pCR demonstrates longer DFS and OS.TDs correlate with poor prognosis.

Programmed cell death 1 inhibitor sintilimab plus concurrent chemoradiotherapy for locally advanced pancreatic adenocarcinoma

BACKGROUND Pancreatic adenocarcinoma,a malignancy that arises in the cells of the pancreas,is a devastating disease with unclear etiology and often poor prognosis.Locally advanced pancreatic cancer,a stage where the tumor has grown significantly but has not yet spread to distant organs,presents unique challenges in treatment.This article aims to discuss the current strategies,challenges,and future directions in the management of locally advanced pancreatic adenocarcinoma(LAPC).AIM To investigate the feasibility and efficacy of programmed cell death 1(PD-1)inhibitor sintilimab plus concurrent chemoradiotherapy for LAPC.METHODS Eligible patients had LAPC,an Eastern cooperative oncology group performance status of 0 or 1,adequate organ and marrow functions,and no prior anticancer therapy.In the observation group,participants received intravenous sintilimab 200 mg once every 3 wk,and received concurrent chemoradiotherapy(concurrent conventional fractionated radiotherapy with doses planning target volume 50.4 Gy and gross tumor volume 60 Gy in 28 fractions and oral S-140 mg/m2 twice daily on days 1-14 of a 21-d cycle and intravenous gemcitabine 1000 mg/m2 on days 1 and 8 of a 21-d cycle for eight cycles until disease progression,death,or unacceptable toxicity).In the control group,participants only received concurrent chemoradiotherapy.From April 2020 to November 2021,64 participants were finally enrolled with 34 in the observation group and 30 in the control group.RESULTS Thirty-four patients completed the scheduled course of chemoradiotherapy,while 32(94.1%)received sintilimab plus concurrent chemoradiotherapy with 2 patients discontinuing sintilimab in the observation group.Thirty patients completed the scheduled course of chemoradiotherapy in the control group.Based on the Response Evaluation Criteria in Solid Tumors guidelines,the analysis of the observation group revealed that a partial response was observed in 11 patients(32.4%),stable disease was evident in 19 patients(55.9%),and 4 patients(11.8%)experienced progressive disease;a partial response was observed in 6(20.0%)patients,stable disease in 18(60%),and progressive disease in 6(20%)in the control group.The major toxic effects were leukopenia and nausea.The incidence of severe adverse events(AEs)(grade 3 or 4)was 26.5%(9/34)in the observation group and 23.3%(7/30)in the control group.There were no treatment-related deaths.The observation group demonstrated a significantly longer median overall survival(22.1 mo compared to 15.8 mo)(P<0.05)and progression-free survival(12.2 mo vs 10.1 mo)(P<0.05)in comparison to the control group.The occurrence of severe AEs did not exhibit a statistically significant difference between the observation group and the control group(P>0.05).CONCLUSION Sintilimab plus concurrent chemoradiotherapy was effective and safe for LAPC patients,and warrants further investigation.

Minimally invasive pelvic exenteration for primary or recurrent locally advanced rectal cancer:A glimpse into the future

Surgeons have grappled with the treatment of recurrent and T4b locally advanced rectal cancer(LARC)for many years.Their main objectives are to increase the overall survival and quality of life of the patients and to mitigate postoperative complications.Currently,pelvic exenteration(PE)with or without neoadjuvant treatment is a curative treatment when negative resection margins are achieved.The traditional open approach has been favored by many surgeons.However,the technological advancements in minimally invasive surgery have radically changed the surgical options.Recent studies have demonstrated promising results in postoperative complications and oncological outcomes after robotic or laparoscopic PE.A recent retrospective study entitled“Feasibility and safety of minimally invasive multivisceral resection for T4b rectal cancer:A 9-year review”was published in the World Journal of Gastrointestinal Surgery.As we read this article with great interest,we decided to delve into the latest data regarding the benefits and risks of minimally invasive PE for LARC.Currently,the small number of suitable patients,limited surgeon experience,and steep learning curve are hindering the establishment of minimally invasive PE.

Evaluation of oxaliplatin and tigio combination therapy in locally advanced gastric cancer

BACKGROUND Locally advanced gastric cancer(LAGC)is a common malignant tumor.In recent years,neoadjuvant chemotherapy has gradually become popular for the treatment of LAGC.AIM To investigate the efficacy of oxaliplatin combined with a tigio neoadjuvant chemotherapy regimen vs a conventional chemotherapy regimen for LAGC.METHODS Ninety patients with LAGC were selected and randomly divided into control and study groups with 45 patients in each group,according to the numerical table method.The control group was treated with conventional chemotherapy,and the study group was treated with oxaliplatin combined with tigio-neoadjuvant che-motherapy.The primary outcome measures were the clinical objective response rate(ORR)and surgical resection rate(SRR),whereas the secondary outcome measures were safety and Karnofsky Performance Status score.RESULTS The ORR in the study group was 80.00%,which was significantly higher than that of the control group(57.78%).In the study group,SRR was 75.56%,which was significantly higher than that of the control group(57.78%).There were 15.56%adverse reactions in the study group and 35.56%in the control group.These differences were statistically significant between the two groups.CONCLUSION The combination of oxaliplatin and tigio before surgery as neoadjuvant chemotherapy for patients with LAGC can effectively improve the ORR and SRR and is safe.

Efficacy evaluation and survival analysis of the combination of oxaliplatin plus Teysuno (SOX) with immune checkpoint inhibitors in the conversion therapy of locally advanced gastric cancer

Background:The efficacy of combining immune checkpoint inhibitors(ICIs)with chemotherapy in neoadjuvant therapy for locally advanced gastric cancer has been explored.However,limited research exists on its effectiveness in conversion therapy,and its superiority over standalone chemotherapy remains to be elucidated.This study aims to investigate the efficacy and survival outcomes of patients treated with ICIs in combination with conversion therapy for locally advanced gastric cancer.Methods:Retrospective data from patients with locally advanced gastric cancer treated with either oxaliplatin+S-1(SOX)alone or in combination with ICIs in conversion therapywere collected.Clinical andpathological characteristics,disease-free survival,andefficacy assessments in nonoperable patients were compared between the 2 treatment groups.Efficacy was further evaluated through dynamic changes in serum markers,and patients’quality of life was assessed using the QLQ-STO22(Gastric Cancer–Specific Quality of Life Questionnaire)quality-of-life measurement scale.Results:A total of 140 patients underwent conversion therapy:80 in the SOX alone group and 60 in the SOX combined with the ICIs group.There were no significant differences in baseline characteristics between the 2 groups.Compared with the SOX alone group,the SOX combined with ICIs group exhibited a higher conversion rate(83.3%vs 75%,P=0.23),R0 resection rate(90.0%vs 83.3%,P=0.31),pathological complete response(pCR)rate(18%vs 5%,P=0.02),median disease-free survival(21.4 vs 16.9 months,P=0.007),the objective response rate in nonoperable patients(60%vs 40%,P=0.301),and median progression-free survival time(7.9 vs 5.7 months,P=0.009).The QLQ-STO22 quality-of-life assessment revealed statistically significant improvements in pain,swallowing difficulties,and dietary restrictions in the combination therapy group compared with those in the monotherapy group.The enhanced efficacy of immune combination with SOX is evident,as demonstrated by the significantly prolonged surgical duration in operated patients(206.6±26.6 min vs 197.8±19.8 min,P=0.35)and intraoperative blood loss(158.9±21.2 mL vs 148.9±25.1 mL,P=0.59).No significant differences were observed in postoperative complications.Conclusions:Compared with the SOX conversion therapy regimen,SOX combined with ICIs demonstrated higher conversion rates,R0 resection rates,pathological response rates,and disease-free survival without increasing surgical difficulty or complications.Nonoperable patients also experienced longer progression-free survival and objective response rates.

Survival prognostic analysis of laparoscopic D2 radical resection for locally advanced gastric cancer: A multicenter cohort study

BACKGROUND With the development of minimally invasive surgical techniques,the use of laparoscopic D2 radical surgery for the treatment of locally advanced gastric cancer(GC)has gradually increased.However,the effect of this procedure on survival and prognosis remains controversial.This study evaluated the survival and prognosis of patients receiving laparoscopic D2 radical resection for the treatment of locally advanced GC to provide more reliable clinical evidence,guide clinical decision-making,optimize treatment strategies,and improve the survival rate and quality of life of patients.METHODS A retrospective cohort study was performed.Clinicopathological data from 652 patients with locally advanced GC in our hospitals from December 2013 to December 2023 were collected.There were 442 males and 210 females.The mean age was 57±12 years.All patients underwent a laparoscopic D2 radical operation for distal GC.The patients were followed up in the outpatient department and by telephone to determine their tumor recurrence,metastasis,and survival.The follow-up period ended in December 2023.Normally distributed data are expressed as the mean±SD,and normally distributed data are expressed as M(Q1,Q3)or M(range).Statistical data are expressed as absolute numbers or percentages;theχ^(2) test was used for comparisons between groups,and the Mann-Whitney U nonparametric test was used for comparisons of rank data.The life table method was used to calculate the survival rate,the Kaplan-Meier method was used to construct survival curves,the log rank test was used for survival analysis,and the Cox risk regression model was used for univariate and multifactor analysis.RESULTS The median overall survival(OS)time for the 652 patients was 81 months,with a 10-year OS rate of 46.1%.Patients with TNM stages II and III had 10-year OS rates of 59.6%and 37.5%,respectively,which were significantly different(P<0.05).Univariate analysis indicated that factors such as age,maximum tumor diameter,tumor diffe-rentiation grade(low to undifferentiated),pathological TNM stage,pathological T stage,pathological N stage(N2,N3),and postoperative chemotherapy significantly influenced the 10-year OS rate for patients with locally advanced GC following laparoscopic D2 radical resection for distal stomach cancer[hazard ratio(HR):1.45,1.64,1.45,1.64,1.37,2.05,1.30,1.68,3.08,and 0.56 with confidence intervals(CIs)of 1.15-1.84,1.32-2.03,1.05-1.77,1.62-2.59,1.05-1.61,1.17-2.42,2.15-4.41,and 0.44-0.70,respectively;P<0.05].Multifactor analysis revealed that a tumor diameter greater than 4 cm,low tumor differentiation,and pathological TNM stage III were independent risk factors for the 10-year OS rate in these patients(HR:1.48,1.44,1.81 with a 95%CI:1.19-1.84).Additionally,postoperative chemotherapy emerged as an independent protective factor for the 10-year OS rate(HR:0.57,95%CI:0.45-0.73;P<0.05).CONCLUSION A maximum tumor diameter exceeding 4 cm,low tumor differentiation,and pathological TNM stage III were identified as independent risk factors for the 10-year OS rate in patients with locally advanced GC following laparoscopic D2 radical resection for distal GC.Conversely,postoperative chemotherapy was found to be an independent protective factor for the 10-year OS rate in these patients.

System of Generalized Vector Quasi-Equilibrium Problems in Locally FC-Spaces

A new class of locally finite continuous topological spaces （for short, locally FC-spaces） and a class of system of generalized vector quasi-equilibrium problems are introduced. By applying a generalized Himmelberg type fixed point theorem for a set-valued mapping with KKM-property due to the author, a collectively fixed point and an equilibrium existence theorem of generalized game are first proved in locally FC-spaces. By applying our equilibrium existence theorem of generalized game, some new existence theorems of equilibrium points for the system of generalized vector quasi-equilibrium problems are proved in locally FC-spaces. These theorems improve, unify and generalize many known results in the literatures.

Current Status and Research Progress of Neoadjuvant Chemotherapy for Locally Advanced Gastric Cancer

Gastric cancer is one of the most common malignant tumours worldwide, with a high degree of malignancy and a poor prognosis. While early gastric cancer can be cured by surgical treatment, locally advanced gastric cancer requires neoadjuvant therapy to shrink the tumour, suppress potential metastases, achieve down-staging, and provide patients with the opportunity for radical surgery to prolong their survival. This article reviews the current status and progress of neoadjuvant chemotherapy for locally advanced gastric cancer.

Clinical implication of naive and memory T cells in locally advanced cervical cancer:A proxy for tumor biology and short-term response prediction

Background:This study was designed to investigate the feasibility of tumor-infiltrating immune cells with different phenotypic characteristics for predicting short-term clinical responses in patients with locally advanced cervical cancer(LACC).Methods:Thirty-four patients who received concurrent chemoradiotherapy and twenty-one patients who merely underwent radiotherapy were enrolled in this study.We retrospectively analyzed the T cell markers(i.e.,CD3,CD4,CD8),memory markers(i.e.,CD45,CCR7),and differentiation markers(i.e.,CD27)in the peripheral blood and tumor tissues of patients with LACC before treatment based on flow cytometry.We also analyzed the relationship of T cell subsets between peripheral blood and tumor tissues,and their correlation with complete response or partial response.Results:The percentage of central memory CD8^(+)TCM(CD8^(+)CD45RA^(−)CD27^(+)CCR7^(+))cells in LACC patients was significantly lower than that of the control group.The percentage of CD8^(+)TN in the peripheral blood of LACC patients was significantly higher than that of tumor tissues.CD8^(+)TEM in the peripheral blood was significantly lower than that of tumor tissues.The percentage of CD8^(+)TN and CD8^(+)TCM in human papillomavirus(HPV)positive samples was significantly higher than that of HPV-negative samples.Similarly,the percentage of CD8^(+)TCM in tumor tissues was significantly higher in cancer tissue samples with lymph nodes compared with those without.Conclusion:A higher proportion of CD4^(+)TCM and a lower proportion of CD8^(+)TN in the tumor microenvironment of LACC may contribute to the therapy response prediction.

Advances in translational therapy for locally advanced gastric cancer

Translational therapy refers to a combination of chemotherapy,radiotherapy,targeted therapy,and immunotherapy for patients with advanced gastric cancer who are initially unable to undergo R0 resection.This treatment can achieve partial or complete remission of the unresectable tumors to meet the criteria for R0 resection,thus enabling the patients to prolong their survival time and improve their quality of life.In gastric cancer,translational therapy has been tried and improved.At present,there are a large number of patients with locally advanced gastric cancer in China,and the selection of suitable patients for transla-tional therapy to prolong objective survival and improve survival quality is one of the hot spots in the field of gastric cancer research.

Developments and challenges in neoadjuvant therapy for locally advanced pancreatic cancer

Pancreatic ductal adenocarcinoma(PDAC)remains a significant public health challenge and is currently the fourth leading cause of cancer-related mortality in developed countries.Despite advances in cancer treatment,the 5-year survival rate for patients with PDAC remains less than 5%.In recent years,neoadjuvant therapy(NAT)has emerged as a promising treatment option for many cancer types,including locally advanced PDAC,with the potential to improve patient outcomes.To analyze the role of NAT in the setting of locally advanced PDAC over the past decade,a systematic literature search was conducted using PubMed and Web of Science.The results suggest that NAT may reduce the local mass size,promote tumor downstaging,and increase the likelihood of resection.These findings are supported by the latest evidence-based medical literature and the clinical experience of our center.Despite the potential benefits of NAT,there are still challenges that need to be addressed.One such challenge is the lack of consensus on the optimal timing and duration of NAT.Improved criteria for patient selection are needed to further identify PDAC patients likely to respond to NAT.In conclusion,NAT has emerged as a promising treatment option for locally advanced PDAC.However,further research is needed to optimize its use and to better understand the role of NAT in the management of this challenging disease.With continued advances in cancer treatment,there is hope of improving the outcomes of patients with PDAC in the future.

Genome-wide investigation to assess copy number variants in the Italian local chicken population

Background Copy number variants(CNV)hold significant functional and evolutionary importance.Numerous ongoing CNV studies aim to elucidate the etiology of human diseases and gain insights into the population structure of livestock.High-density chips have enabled the detection of CNV with increased resolution,leading to the identification of even small CNV.This study aimed to identify CNV in local Italian chicken breeds and investigate their distribution across the genome.Results Copy number variants were mainly distributed across the first six chromosomes and primarily associated with loss type CNV.The majority of CNV in the investigated breeds were of types 0 and 1,and the minimum length of CNV was significantly larger than that reported in previous studies.Interestingly,a high proportion of the length of chromosome 16 was covered by copy number variation regions(CNVR),with the major histocompatibility complex being the likely cause.Among the genes identified within CNVR,only those present in at least five animals across breeds(n=95)were discussed to reduce the focus on redundant CNV.Some of these genes have been associated to functional traits in chickens.Notably,several CNVR on different chromosomes harbor genes related to muscle development,tissue-specific biological processes,heat stress resistance,and immune response.Quantitative trait loci(QTL)were also analyzed to investigate potential overlapping with the identified CNVR:54 out of the 95 gene-containing regions overlapped with 428 QTL associated to body weight and size,carcass characteristics,egg production,egg components,fat deposition,and feed intake.Conclusions The genomic phenomena reported in this study that can cause changes in the distribution of CNV within the genome over time and the comparison of these differences in CNVR of the local chicken breeds could help in preserving these genetic resources.

Deep brain implantable microelectrode arrays for detection and functional localization of the subthalamic nucleus in rats with Parkinson’s disease

The subthalamic nucleus(STN)is considered the best target for deep brain stimulation treatments of Parkinson’s disease(PD).It is difficult to localize the STN due to its small size and deep location.Multichannel microelectrode arrays(MEAs)can rapidly and precisely locate the STN,which is important for precise stimulation.In this paper,16-channel MEAs modified with multiwalled carbon nanotube/poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(MWCNT/PEDOT:PSS)nanocomposites were designed and fabricated,and the accurate and rapid identification of the STN in PD rats was performed using detection sites distributed at different brain depths.These results showed that nuclei in 6-hydroxydopamine hydrobromide(6-OHDA)-lesioned brains discharged more intensely than those in unlesioned brains.In addition,the MEA simultaneously acquired neural signals from both the STN and the upper or lower boundary nuclei of the STN.Moreover,higher values of spike firing rate,spike amplitude,local field potential(LFP)power,and beta oscillations were detected in the STN of the 6-OHDA-lesioned brain,and may therefore be biomarkers of STN localization.Compared with the STNs of unlesioned brains,the power spectral density of spikes and LFPs synchronously decreased in the delta band and increased in the beta band of 6-OHDA-lesioned brains.This may be a cause of sleep and motor disorders associated with PD.Overall,this work describes a new cellular-level localization and detection method and provides a tool for future studies of deep brain nuclei.

Numerical study on local scour characteristics around submarine pipelines in the Yellow River Delta silty sandy soil under waves and currents

Due to their high reliability and cost-efficiency,submarine pipelines are widely used in offshore oil and gas resource engineering.Due to the interaction of waves,currents,seabed,and pipeline structures,the soil around submarine pipelines is prone to local scour,severely affecting their operational safety.With the Yellow River Delta as the research area and based on the renormalized group(RNG)k-εturbulence model and Stokes fifth-order wave theory,this study solves the Navier-Stokes(N-S)equation using the finite difference method.The volume of fluid(VOF)method is used to describe the fluid-free surface,and a threedimensional numerical model of currents and waves-submarine pipeline-silty sandy seabed is established.The rationality of the numerical model is verified using a self-built waveflow flume.On this basis,in this study,the local scour development and characteristics of submarine pipelines in the Yellow River Delta silty sandy seabed in the prototype environment are explored and the influence of the presence of pipelines on hydrodynamic features such as surrounding flow field,shear stress,and turbulence intensity is analyzed.The results indicate that(1)local scour around submarine pipelines can be divided into three stages:rapid scour,slow scour,and stable scour.The maximum scour depth occurs directly below the pipeline,and the shape of the scour pits is asymmetric.(2)As the water depth decreases and the pipeline suspension height increases,the scour becomes more intense.(3)When currents go through a pipeline,a clear stagnation point is formed in front of the pipeline,and the flow velocity is positively correlated with the depth of scour.This study can provide a valuable reference for the protection of submarine pipelines in this area.

Dynamical analysis,geometric control and digital hardware implementation of a complex-valued laser system with a locally active memristor

In order to make the peak and offset of the signal meet the requirements of artificial equipment,dynamical analysis and geometric control of the laser system have become indispensable.In this paper,a locally active memristor with non-volatile memory is introduced into a complex-valued Lorenz laser system.By using numerical measures,complex dynamical behaviors of the memristive laser system are uncovered.It appears the alternating appearance of quasi-periodic and chaotic oscillations.The mechanism of transformation from a quasi-periodic pattern to a chaotic one is revealed from the perspective of Hamilton energy.Interestingly,initial-values-oriented extreme multi-stability patterns are found,where the coexisting attractors have the same Lyapunov exponents.In addition,the introduction of a memristor greatly improves the complexity of the laser system.Moreover,to control the amplitude and offset of the chaotic signal,two kinds of geometric control methods including amplitude control and rotation control are designed.The results show that these two geometric control methods have revised the size and position of the chaotic signal without changing the chaotic dynamics.Finally,a digital hardware device is developed and the experiment outputs agree fairly well with those of the numerical simulations.

Synchronization coexistence in a Rulkov neural network based on locally active discrete memristor

At present, many neuron models have been proposed, which can be divided into discrete neuron models and continuous neuron models. Discrete neuron models have the advantage of faster simulation speed and the ease of understanding complex dynamic phenomena. Due to the properties of memorability, nonvolatility, and local activity, locally active discrete memristors(LADMs) are also suitable for simulating synapses. In this paper, we use an LADM to mimic synapses and establish a Rulkov neural network model. It is found that the change of coupling strength and the initial state of the LADM leads to multiple firing patterns of the neural network. In addition, considering the influence of neural network parameters and the initial state of the LADM, numerical analysis methods such as phase diagram and timing diagram are used to study the phase synchronization. As the system parameters and the initial states of the LADM change, the LADM coupled Rulkov neural network exhibits synchronization transition and synchronization coexistence.