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.

Concurrent Constraint Programming:A Language and Its Execution Model

To overcome inefficiency in traditional logic programming, a declarative programming language COPS is designed based on the notion of concurrent constraint programming (CCP). The improvement is achieved by the adoption of constraint-based heuristic strategy and the introduction of deterministic components in the framework of CCP. Syntax specification and an operational semantic description are presented.

A Comparative Study on Test Case Generation of Concurrent Programs

This paper deals with a comparative study on testing of concurrent programs based on different techniques. The various challenges in testing concurrent programming are: defining test coverage criteria based on control flow, generating control flow graph of nondeterministic programs, investigating the applicability of sequential testing criteria to parallel program testing etc. For solving these issues, some existing techniques are discussed in this study. Various researchers use an intermediate graph called Event Inter Actions Graph (EIAG) to solve the problem of generating the control flow graph of nondeterministic programs. Some researches propose an intermediate graph called Interaction Sequence Testing Criteria (ISTC) approach based on sequence of interactions to solve the problem of test coverage criteria based on control and data flow. Another method to solve the problem of generating test coverage based on control flow graph of nondeterministic programs is constraint based approach. It needs constrained elements to generate test case which includes structural element and constraint. The selection of good test cases has been addressed by test data generation technique. The technique of concurrent path analysis approach is used to solve the problem of applicability of sequential testing criteria to parallel program testing. It reduces the number of combined concurrent test paths. The sequential test paths are combined to form concurrent test path. The Integration and System Test Automation (ISTA) approach is used to solve the problem of applicability of sequential testing criteria to parallel program testing. It is used for automated test case generation and execution by using high-level Petri net is a finite state test model.

Towards a Categorical Framework for Verifying Design and Implementation of Concurrent Systems

Process-oriented design and implementation of concurrent systems has important benefits. However, the inherent complexity of concurrent processes’ communication imposes challenges such as verifying consistency between the process-oriented design and implementation of a concurrent system. To deal with such a challenge, we use Galois connections, Failures and Category Theory to construct a formal framework for designing, implementing, analyzing and verifying consistency of concurrent systems. For the purpose of illustrating the framework, a running concurrent system is designed by Communicating Sequential Processes, implemented by a process-oriented programming language Erasmus.

Dynamically Translating Binary Code for Multi-Threaded Programs Using Shared Code Cache

mc211vm is a process-level ARM-to-x86 binary translator developed in our lab in the past several years. Currently, it is able to emulate singlethreaded programs. We extend mc211vm to emulate multi-threaded programs. Our main task is to reconstruct its architecture for multi-threaded programs. Register mapping, code cache management, and address mapping in mc2llvm have all been modified. In addition, to further speed up the emulation, we collect hot paths, aggressively optimize and generate code for them at run time. Additional threads are used to alleviate the overhead. Thus, when the same hot path is walked through again, the corresponding optimized native code will be executed instead. In our experiments, our system is 8.8X faster than QEMU （quick emulator） on average when emulating the specified benchmarks with 8 guest threads.

Research and Review on the Java Multi-thread Programming and Its Further Development Tendency

In this paper, we conduct research on the Java multi-thread programming and its further development tendency. Multithreading mechanisms can run several programs at the same time, make the program run effi ciency becomes higher that also can overcome the problem of basic traditional programming language design while its design is the key to the realization of the synchronous thread. Multithreading is a mechanism that allows concurrent execution of multiple instruction stream in the program, each instruction stream is called a thread, independent from each other between each other. Thread is also known as a lightweight process, it have independent execution and process control. Our research starts from the analysis of the corresponding mechanism to enhance the performance that is innovative and meaningful.

A Generic Graph Model for WCET Analysis of Multi-Core Concurrent Applications

Worst-case execution time (WCET) analysis of multi-threaded software is still a challenge. This comes mainly from the fact that synchronization has to be taken into account. In this paper, we focus on this issue and on automatically calculating and incorporating stalling times (e.g. caused by lock contention) in a generic graph model. The idea that thread interleavings can be studied with a matrix calculus is novel in this research area. Our sparse matrix representations of the program are manipulated using an extended Kronecker algebra. The resulting graph represents multi-threaded programs similar as CFGs do for sequential programs. With this graph model, we are able to calculate the WCET of multi-threaded concurrent programs including stalling times which are due to synchronization. We employ a generating function-based approach for setting up data flow equations which are solved by well-known elimination-based dataflow analysis methods or an off-the-shelf equation solver. The WCET of multi-threaded programs can finally be calculated with a non-linear function solver.

多源遥感卫星地面调度系统设计与实现

针对卫星地面调度处理系统进行研究与设计,着重关注工作流、线程池和Redis缓存等关键技术。首先,对工作流的分析和建模以提高系统任务的执行效率和资源利用率。其次,引入线程池技术来管理和调度系统中的线程资源,实现任务的并发执行和负载均衡,提高系统的吞吐量和响应速度。最后,利用Redis缓存作为系统的缓存和Kafka消息队列,优化数据存取和通信效率,提供更高的性能和可靠性。整体通过SpringBoot框架进行实验和性能评估,验证了该系统在任务处理能力、资源利用率和数据访问效率等方面的优势。本研究对于提高卫星地面调度处理系统的效率和性能具有一定的实践意义和推广价值。

循环肿瘤细胞上细胞程序性死亡配体1表达对宫颈癌同步放化疗预后的评估价值

目的探讨循环肿瘤细胞(CTC)上细胞程序性死亡配体1(PD-L1)表达对宫颈癌同步放化疗预后的评估价值。方法回顾性选取2021年6月至2023年12月入临汾市人民医院的60例宫颈癌患者,均经病理学确诊,CTC PD-L1经CytoSorter CTC系统测定。对宫颈癌病理特征与PD-L1^(+)CTC之间的相关性予以分析,并比较PD-L1^(+)CTC和PD-L1-CTC宫颈癌患者同步放化疗前后的无进展生存期(PFS),评估宫颈癌放化疗后PD-L1^(+)CTC数量对预后的评估价值。结果同步放化疗前后外周血CTC检出率及数量比较,差异无统计学意义(P>0.05)。较同步放化疗前,宫颈癌患者同步放化疗后PD-L1^(+)CTC检出率更低(38.33%vs.56.67%),PD-L1^(+)CTC检出数量更少[(0.77±1.20)个vs.(1.27±1.51)个],差异均有统计学意义(P<0.05)。同步放化疗前,宫颈癌患者PD-L1^(+)CTC与肿瘤直径、FIGO分期、分化程度及淋巴结转移联系紧密(P<0.05)。同步放化疗后,宫颈癌患者PD-L1^(+)CTC表达水平与肿瘤直径、FIGO分期、分化程度及淋巴结转移密切相关(P<0.05)。PD-L1^(+)CTC患者的PFS短于PD-L1-CTC患者,差异有统计学意义(P<0.05)。Cox回归分析显示,局部晚期宫颈癌患者同步放化疗前后的CTC PD-L1表达水平均可作为PFS预后因素。结论宫颈癌放同步放化疗前后测定的CTC PD-L1表达水平可作为预后评估的辅助指标。

Precise slicing of interprocedural concurrent programs

Program slicing is an effective technique for an- alyzing concurrent programs. However, when a conventional closure-based slicing algorithm for sequential programs is ap- plied to a concurrent interprocedural program, the slice is usually imprecise owing to the intransitivity of interference dependence. Interference dependence arises when a state- ment uses a variable defined in another statement executed concurrently. In this study, we propose a global dependence analysis approach based on a program reachability graph, and construct a novel dependence graph called marking-statement dependence graph （MSDG）, in which each vertex is a 2-tuple of program state and statement. In contrast to the conven- tional program dependence graph where the vertex is a state- ment, the dependence relation in MSDG is transitive. When traversing MSDG, a precise slice will be obtained. To en- hance the slicing efficiency without loss of precision, our slic- ing algorithm adopts a hybrid strategy. The procedures con- taining interaction statements between threads are inlined and sliced by the slicing algorithm based on program reachability graphs while allowing other procedures to be sliced as se- quential programs. We have implemented our algorithm and three other representative slicing algorithms, and conducted an empirical study on concurrent Java programs. The exper- imental results show that our algorithm computes more pre- cise slices than the other algorithms. Using partial-order re- duction techniques, which are effective for reducing the size of a program reachability graph without loss of precision, ouralgorithm is optimized, thereby improving its performance to some extent.

Certifying Concurrent Programs Using Transactional Memory

Transactional memory （TM） is a new promising concurrency-control mechanism that can avoid many of the pitfalls of the traditional lock-based techniques. TM systems handle data races between threads automatically so that programmers do not have to reason about the interaction of threads manually. TM provides a programming model that may make the development of multi-threaded programs easier. Much work has been done to explore the various implementation strategies of TM systems and to achieve better performance, but little has been done on how to formally reason about programs using TM and how to make sure that such reasoning is sound. In this paper, we focus on the semantics of transactional memory and present a proof-carrying code （PCC） system for reasoning about programs using TM . We formalize our reasoning with respect to the TM semantics, prove its soundness, and use examples to demonstrate its effectiveness.

Verification of Concurrent Assembly Programs with a Petri Net Based Safety Policy

Concurrent programs written in a machine level language are being used in many areas but verification of such programs brings new challenges to the programming language community. Most of the studies in the literature on verifying the safety properties of concurrent programs are for high-level languages, specifications, or calculi. Therefore, more studies are needed on concurrency verification for machine level language programs. This paper describes a framework of a Petri net based safety policy for the verification of concurrent assembly programs, to exploit the capability of Petri nets in concurrency modeling. The concurrency safety properties can be considered separately using the net structure and by mixing Hoare logic and computational tree logic. Therefore, more useful higher-level safety properties can be specified and verified.

基于交互式定理证明的并发程序验证工作综述

并发程序与并发系统可以拥有非常高的执行效率和相对串行系统较快的响应速度,在现实中有着非常广泛的应用.但是并发程序与并发系统往往难以保证其实现的正确性,实际应用程序运行中的错误会带来严重的后果.同时,并发程序执行时的不确定性会给其正确性验证带来巨大的困难.在形式化验证方法中,人们可以通过交互式定理证明器严格地对并发程序进行验证.对在交互式定理证明中可用于描述并发程序正确性的验证目标进行总结,它们包括霍尔三元组、可线性化、上下文精化和逻辑原子性.交互式定理证明方法中常用程序逻辑对程序进行验证,分析基于并发分离逻辑、依赖保证逻辑、关系霍尔逻辑等理论研究的系列成果与相应形式化方案,并对使用这些方法的程序验证工具和程序验证成果进行总结.

SYN-Sequence Selection Strategy for Testing Concurrent Programs Based on Little Strong Happened-Before

This paper defines a new relation--little strong happened-before（LSHB） and presents the algorithm for LSHB. Compared with strong happened-before （SHB） and weak happened- before （WHB）, LSHB supports keeping-read-result and ensures definite sufficiency of testing. Equivalence partitioning the set of SYN-sequences based on LSHB can efficiently reduce the number of testing SYN-sequences. The case studies prove that LSHB has high practicability.

ρ Graph: Rendezvous Ordering Graph forAda Concurrent Programs

In disciplined Ada software development and maintenance, an adequate and suitable graphical representation for concurrency is important. To describe rendezvous ordering, tasking andexecuting flow of tasks, p graph--Rendezvous Ordering Graph is presenced in this paper. pgraph is a kind of-hierarchical oriented graph with nodes representing rendezvouses and edgesshowing'ordering relations between rendezvouses as well as flow of tasks. It can be used insoftware understanding, design description and documentation.

多线程程序数据竞争的静态检测

多线程并发程序的广泛使用带来了更多的数据竞争错误·传统的数据竞争静态检测由于对并发语义和别名信息的保守分析会导致很多假错误·因此,提出了一个精确有效的静态检测框架:分析应用了精确的别名分析并静态模拟了访问事件发生序;为提高分析效率,检测算法提出了一个以对象为中心,结合Escape分析缩小检测范围的检测算法并配合设计了压缩的别名等价类表示·检测框架在一个静态Java编译器JTool上做了实现,对于测试程序取得了很好的分析结果·

一种基于程序可达图的并发程序依赖性分析方法

依赖性分析是一种重要的程序分析手段.针对多线程共享变量通信机制,本文在提出一种新的并发程序表示—线程交互可达图(tIRG)的基础上,从全局分析并发程序的依赖关系,构建了以程序状态和语句二元组为节点的并发程序依赖图(MSDG).与传统的以语句为节点的并发程序依赖图相比,MSDG图中依赖关系不仅精确,且具有可传递性,对其遍历可获得高精度的并发程序切片,精度和效率较其它高精度切片方法有显著提高.

一种并发程序依赖性分析方法

并发程序的依赖性分析是并发程序分析、理解、调试、测试和维护的重要手段 .由于并发程序执行的不确定性 ,目前 ,尚有很多难点有待解决 .针对 Ada任务机制 ,首先提出了一种简洁、有效的并发程序表示方法——并发程序流图 ,然后讨论了由任务间同步引起的同步依赖和由访问共享变量引起的任务间数据依赖 ,建立了并发程序依赖图 ,并在此基础上给出了一种有效的并发程序依赖性分析算法 ,得到一个比较精确的依赖集 。

网络程序设计中的并发复杂性

互联网已成为现代社会的重要信息基础设施,然而网络环境的并发性使得传统程序设计方法在开发高质量的网络程序时遇到了许多困难,严重影响了开发效率.并发问题对网络程序开发复杂度的影响可以类比多核处理器带来的"软件并发危机",然而其中的并发问题却远远没有得到应有的重视.网络并发问题目前并不存在普适的应对方法,甚至在不同方法之间存在明显的争论.简要介绍了各种基本的并发模型及其常见的实现方法,并在此基础上着重分析了现有方法的内在复杂性,对比各种方法的优势与劣势,最后展望可能的研究和发展方向.

基于有限状态机建模的单片机编程方法研究

普通高等院校非计算机专业的学生编写复杂单片机程序会遇到困难.有限状态机是一种功能强大、有效易懂、适合处理多任务并发和阻塞等难题的编程方法.详细介绍了有限状态机程序设计方法,并运用实例说明该方法,可以降低程序复杂度,使用者可以轻松编写出有一定难度的程序.