Volume Diffuse Dielectric Barrier Discharge Plasma Produced by Nanosecond High Voltage Pulse in Airflow

Volume diffuse dielectric barrier discharge （DBD） plasma is produced in subsonic airflow by nanosecond high-voltage pulse power supply with a plate-to-plate discharge cell at 6 mm air gap length. The discharge images, optical emission spectra （OES）, the applied voltage and current waveforms of the discharge at the changed airflow rates are obtained. When airflow rate is increased, the transition of the discharge mode and the variations of discharge intensity, breakdown characteristics and the temperature of the discharge plasma are investigated. The results show that the discharge becomes more diffuse, discharge intensity is decreased accompanied by the increased breakdown voltage and time lag, and the temperature of the discharge plasma reduces when airflow of small velocity is introduced into the discharge gap. These phenomena are because that the airflow changes the spatial distribution of the heat and the space charge in the discharge gap.

Simulation of the Ecosystem Productivity Responses to Aerosol Diffuse Radiation Fertilization Effects over the Pan-Arctic during 2001–19

The pan-Arctic is confronted with air pollution transported from lower latitudes.Observations have shown that aerosols help increase plant photosynthesis through the diffuse radiation fertilization effects(DRFEs).While such DRFEs have been explored at low to middle latitudes,the aerosol impacts on pan-Arctic ecosystems and the contributions by anthropogenic and natural emission sources remain less quantified.Here,we perform regional simulations at 0.2o×0.2ousing a well-validated vegetation model(Yale Interactive terrestrial Biosphere,YIBs)in combination with multi-source of observations to quantify the impacts of aerosol DRFEs on the net primary productivity(NPP)in the pan-Arctic during 2001-19.Results show that aerosol DRFEs increase pan-Arctic NPP by 2.19 Pg C(12.8%)yr^(-1)under clear-sky conditions,in which natural and anthropogenic sources contribute to 8.9% and 3.9%,respectively.Under all-sky conditions,such DRFEs are largely dampened by cloud to only 0.26 Pg C(1.24%)yr^(-1),with contributions of 0.65% by natural and 0.59% by anthropogenic species.Natural aerosols cause a positive NPP trend of 0.022% yr^(-1)following the increased fire activities in the pan-Arctic.In contrast,anthropogenic aerosols induce a negative trend of-0.01% yr^(-1)due to reduced emissions from the middle latitudes.Such trends in aerosol DRFEs show a turning point in the year of 2007 with more positive NPP trends by natural aerosols but negative NPP trends by anthropogenic aerosols thereafter.Though affected by modeling uncertainties,this study suggests a likely increasing impact of aerosols on terrestrial ecosystems in the pan-Arctic under global warming.

Transition from a filamentary mode to a diffuse one with varying distance from needle to stream of an argon plasma jet

Plasma jet has extensive application potentials in various fields, which normally operates in a diffuse mode when helium is used as the working gas. However, when less expensive argon is used, the plasma jet often operates in a filamentary mode. Compared to the filamentary mode, the diffuse mode is more desirable for applications. Hence, many efforts have been exerted to accomplish the diffuse mode of the argon plasma jet. In this paper, a novel single-needle argon plasma jet is developed to obtain the diffuse mode. It is found that the plasma jet operates in the filamentary mode when the distance from the needle tip to the central line of the argon stream(d) is short. It transits to the diffuse mode with increasing d. For the diffuse mode, there is always one discharge pulse per voltage cycle, which initiates at the rising edge of the positive voltage. For comparison, the number of discharge pulse increases with an increase in the peak voltage for the filamentary mode. Fast photography reveals that the plasma plume in the filamentary mode results from a guided positive streamer,which propagates in the argon stream. However, the plume in the diffuse mode originates from a branched streamer, which propagates in the interfacial layer between the argon stream and the surrounding air. By optical emission spectroscopy,plasma parameters are investigated for the two discharge modes, which show a similar trend with increasing d. The diffuse mode has lower electron temperature, electron density, vibrational temperature, and gas temperature compared to the filamentary mode.

Formation of diffuse and spark discharges between two needle electrodes with the scattering of particles

The development of a nanosecond discharge in a pin-to-pin gap filled with air at atmospheric pressure has been studied with high temporal and spatial resolutions from a breakdown start to the spark decay.Positive and negative nanosecond voltage pulses with an amplitude of tens of kilovolts were applied.Time-resolved images of the discharge development were taken with a fourchannel Intensified Charge Coupled Device(ICCD)camera.The minimum delay between the camera channels could be as short as≈0.1 ns.This made it possible to study the gap breakdown process with subnanosecond resolution.It was observed that a wide-diameter streamer develops from the high-voltage pointed electrode.The ionization processes near the grounded pin electrode started when the streamer crossed half of the gap.After bridging the gap by the streamer,a diffuse discharge was formed.The development of spark leaders from bright spots on the surface of the pointed electrodes was observed at the next stage.It was found that the rate of development of the spark leader is an order of magnitude lower than that of the wide-diameter streamer.Long thin luminous tracks were observed against the background of a discharge plasma glow.It has been established that the tracks are adjacent to brightly glowing spots on the electrodes and are associated with the flight of small particles.

RPRD1B/CREPT facilitates the progression of diffuse large B-cell lymphoma by inhibiting apoptosis through the NF-κB signaling pathway

Objective:To investigate the role of RPRD1B in the progression of diffuse large B-cell lymphoma(DLBCL)and its potential as a therapeutic target.Methods:This study analyzed RPRD1B expression in DLBCL and normal tissues using public databases and assessed its prognostic impact through survival analysis.In vitro and in vivo experiments were conducted to explore the mechanisms by which RPRD1B influences tumor growth and apoptosis.Results:RPRD1B expression was significantly elevated in DLBCL compared to normal tissues and was associated with poor prognosis.In vitro and in vivo experiments demonstrated that RPRD1B promoted lymphoma cell proliferation and inhibited apoptosis through the NF-κB signaling pathway.Conclusions:RPRD1B plays a critical role in the progression of DLBCL by modulating apoptosis and cellular proliferation.Targeting RPRD1B may offer a novel therapeutic strategy for DLBCL,suggesting its potential as a prognostic marker and therapeutic target in hematological malignancies.

Influence of bias voltage and oxygen addition on the discharge aspects of a diffuse argon plume in an atmospheric pressure plasma jet

A remote plasma,also referred to as a plasma plume(diffuse or filamentary),is normally formed downstream of an atmospheric pressure plasma jet.In this study,a diffuse plume is formed by increasing the bias voltage(U_(b))applied to the downstream electrode of an argon plasma jet excited by a negatively pulsed voltage.The results indicate that the plume is filamentary when U_(b)is low,which transits to the diffuse plume with increasing U_(b).The discharge initiated at the rising edge of the pulsed voltage is attributed to the diffuse plume,while that at the falling edge contributes to the filament in the plume.For the diffuse plume,the discharge intensity decreases with the increasing oxygen content(C_o).Fast photography reveals that the diffuse plume results from a negative streamer,which has a dark region near the nozzle with C_o=0%.However,the dark region is absent with C_o=0.5%.From the optical emission spectrum,the electron density,electron excitation temperature,gas temperature,and oxygen atom concentration are investigated.

Extragastrointestinal stromal tumors with diffuse membranous distribution with bleeding:A case report

BACKGROUND Extragastrointestinal stromal tumors(EGIST)and gastrointestinal stromal tumors are of similar pathological type and form.Here we report a rare case of EGIST diffusely distributed in membranous tissue in abdominal cavity,the feature of which included diffuse tumors at membranous tissue in entire abdominal cavity and spontaneous bleeding of the tumors.CASE SUMMARY The patient was a 71-year man and hospitalized due to continuous pain at lower abdomen for more than 10 days.Upon physical examination,the patient had flat and tough abdomen with mild pressing pain at lower abdomen,no obvious abdominal mass was touchable,and shifting dullness was positive.Positron emission tomography-computed tomography(CT)showed that in his peritoneal cavity,there were multiple nodules of various sizes,seroperitoneum,multiple enlarged lymph nodes in abdominal/pelvic cavity and right external ilium as well as pulmonary nodules.Plain CT scanning at epigastrium/hypogastrium/pelvic cavity+enhanced three-dimensional reconstruction revealed multiple soft tissue nodules in abdominal/pelvic cavity,peritoneum and right groin.Tumor marker of carbohydrate antigen 125 was 808 U/mL,diffuse tuberous tumor was seen in abdominal/pelvic cavity during operation with hematocelia,and postoperative pathological examination confirmed EGIST.Imatinib was administered with better therapeutic effect.CONCLUSION Gene testing showed breast cancer susceptibility gene 1 interacting protein C-terminal helicase 1 and KIT genovariation,and the patient was treated with imatinib follow-up visit found that his clinical symptoms disappeared and the tumor load alleviated obviously via imageological examination.

Identifying relevant factors influencing cancer-related fatigue in patients with diffuse large B-cell lymphoma during chemotherapy

BACKGROUND Diffuse large B-cell lymphoma(DLBCL)is a rapidly growing malignant tumor,and chemotherapy is one of the treatments used to combat it.Although advancements of science and technology have resulted in more and more patients being able to receive effective treatment,they still face side effects such as fatigue and weakness.It is important to thoroughly investigate the factors that contribute to cancer-related fatigue(CRF)during chemotherapy.AIM To explore the factors related to CRF,anxiety,depression,and mindfulness levels in patients with DLBCL during chemotherapy.METHODS General information was collected from the electronic medical records of eligible patients.Sleep quality and mindfulness level scores in patients with DLBCL during chemotherapy were evaluated by the Pittsburgh Sleep Quality Index and Five Facet Mindfulness Questionnaire-Short Form.The Piper Fatigue Scale was used to evaluate the CRF status.The Self-Rating Anxiety Scale and Self-Rating Depression Scale were used to evaluate anxiety and depression status.Univariate analysis and multivariate regression analysis were used to investigate the factors related to CRF.RESULTS The overall average CRF level in 62 patients with DLBCL during chemotherapy was 5.74±2.51.In 25 patients,the highest rate of mild fatigue was in the cognitive dimension(40.32%),and in 35 patients the highest moderate fatigue rate in the behavioral dimension(56.45%).In the emotional dimension,severe fatigue had the highest rate of occurrence,34 cases or 29.03%.The CRF score was positively correlated with cancer experience(all P<0.01)and negatively correlated with cancer treatment efficacy(all P<0.01).Tumor staging,chemotherapy cycle,self-efficacy level,and anxiety and depression level were related to CRF in patients with DLBCL during chemotherapy.CONCLUSION There was a significant correlation between CRF and perceptual control level in patients.Tumor staging,chemotherapy cycle,self-efficacy level,and anxiety and depression level influenced CRF in patients with DLBCL during chemotherapy.

Study of three-dimensional spatial diffuse discharge in contact electrode structure applied to air purification

In this work,based on the role of pre-ionization of the non-uniform electric field and its effect of reducing the collisional ionization coefficient,a diffuse dielectric barrier discharge plasma is formed in the open space outside the electrode structure at a lower voltage by constructing a three-dimensional non-uniform spatial electric field using a contact electrode structure.The air purification study is also carried out.Firstly,a contact electrode structure is constructed using a three-dimensional wire electrode.The distribution characteristics of the spatial electric field formed by this electrode structure are analyzed,and the effects of the non-uniform electric field and the different angles of the vertical wire on the generation of three-dimensional spatial diffuse discharge are investigated.Secondly,the copper foam contact electrode structure is constructed using copper foam material,and the effects of different mesh sizes on the electric field distribution are analyzed.The results show that as the mesh size of the copper foam becomes larger,a strong electric field region exists not only on the surface of the insulating layer,but also on the surface of the vertical wires inside the copper foam,i.e.,the strong electric field region shows a three-dimensional distribution.Besides,as the mesh size increases,the area of the vertical strong electric field also increases.However,the electric field strength on the surface of the insulating layer gradually decreases.Therefore,the appropriate mesh size can effectively increase the discharge area,which is conducive to improving the air purification efficiency.Finally,a highly permeable stacked electrode structure of multilayer wire-copper foam is designed.In combination with an ozone treatment catalyst,an air purification device is fabricated,and the air purification experiment is carried out.

Association of overall survival benefit of radiotherapy with progression-free survival after chemotherapy for diffuse large B-cell lymphoma:A systematic review and meta-analysis

Objective:To evaluate whether improved progression-free survival(PFS)from radiotherapy(RT)translates into an overall survival(OS)benefit for diffuse large B-cell lymphoma(DLBCL).Methods:A systematic literature search identified randomized controlled trials(RCTs)and retrospective studies that compared combined-modality therapy(CMT)with chemotherapy(CT)alone.Weighted regression analyses were used to estimate the correlation between OS and PFS benefits.Cohen’s kappa statistic assessed the consis-tency between DLBCL risk-models and PFS patterns.Furthermore,the benefit trend of RT was analyzed by fitting a linear regression model to the pooled hazard ratio(HR)according to the PFS patterns.Results:For both 7 RCTs and 52 retrospective studies,correlations were found between PFS HR(HRPFS)and OS HR(HROS)at trial level(r=0.639-0.876),and between PFS and OS rates at treatment-arm level,regardless of CT regimens(r=0.882-0.964).Incorporating RT into CT increased about 18%of PFS,and revealed a different OS benefit profile.Patients were stratified into four CT-generated PFS patterns(>80%,>60-80%,>40-60%,and≤40%),which was consistent with risk-stratified subgroups(kappa>0.6).Absolute gain in OS from RT ranged from≤5%at PFS>80%to about 21%at PFS≤40%,with pooled HROS from 0.70(95%CI,0.51-0.97)to 0.48(95%CI,0.36-0.63)after rituximab-based CT.The OS benefit of RT was predominant in intermediate-and high-risk patients with PFS≤80%.Conclusion:We demonstrated a varied OS benefit profile of RT to inform treatment decisions and clinical trial design.

基于Diffusers框架的电商产品图制作方法研究

基于Diffusers框架与Control Net网络,文章开发并实现了服装产品图的制作流程,将Segment Anything与Grounding DINO结合,实现了自动分割衣服蒙版。将Semantic Segmentation与ViTmatte结合,实现了对皮肤的精细化分割。文章使用大模型的低秩适应实现了对图像风格的微调,利用Ultralytics框架,结合Diffusers提出了一种图像修复方法。将生成图与原图对比,实验结果表明:将Diffusers与Control Net网络结合,能够实现模特替换与背景替换,该方法可以为用户提供衣服上身的参考,降低商家的产品图制作成本。

Recent Advances in Fibrous Materials for Hydroelectricity Generation

Depleting fossil energy sources and conventional polluting power generation pose a threat to sustainable development.Hydroelectricity generation from ubiquitous and spontaneous phase transitions between liquid and gaseous water has been considered a promising strategy for mitigating the energy crisis.Fibrous materials with unique flexibility,processability,multifunctionality,and practicability have been widely applied for fibrous materials-based hydroelectricity generation(FHG).In this review,the power generation mechanisms,design principles,and electricity enhancement factors of FHG are first introduced.Then,the fabrication strategies and characteristics of varied constructions including 1D fiber,1D yarn,2D fabric,2D membrane,3D fibrous framework,and 3D fibrous gel are demonstrated.Afterward,the advanced functions of FHG during water harvesting,proton dissociation,ion separation,and charge accumulation processes are analyzed in detail.Moreover,the potential applications including power supply,energy storage,electrical sensor,and information expression are also discussed.Finally,some existing challenges are considered and prospects for future development are sincerely proposed.

Defect Engineering:Can it Mitigate Strong Coulomb Effect of Mg^(2+)in Cathode Materials for Rechargeable Magnesium Batteries?

Rechargeable magnesium batteries(RMBs)have been considered a promising“post lithium-ion battery”system to meet the rapidly increasing demand of the emerging electric vehicle and grid energy storage market.However,the sluggish diffusion kinetics of bivalent Mg^(2+)in the host material,related to the strong Coulomb effect between Mg^(2+)and host anion lattices,hinders their further development toward practical applications.Defect engineering,regarded as an effective strategy to break through the slow migration puzzle,has been validated in various cathode materials for RMBs.In this review,we first thoroughly understand the intrinsic mechanism of Mg^(2+)diffusion in cathode materials,from which the key factors affecting ion diffusion are further presented.Then,the positive effects of purposely introduced defects,including vacancy and doping,and the corresponding strategies for introducing various defects are discussed.The applications of defect engineering in cathode materials for RMBs with advanced electrochemical properties are also summarized.Finally,the existing challenges and future perspectives of defect engineering in cathode materials for the overall high-performance RMBs are described.

Equivalent Doping Transformation Method for Predicting Breakdown Voltage and Peak Field at Breakdown of Epitaxial-Diffused Punch-Through Junction

Based on a new semi empirical analytical method, namely equivalent doping transformation, the breakdown voltage and the peak field of the epitaxial diffused punch through junction have been obtained. The basic principle of this method is introduced and a set of breakdown voltage and peak field plots are provided for the optimum design of the low voltage power devices. It shows that the analytical results coincide with the previous numerical simulation well.

EFFECT OF DUMP GAP ON TOTAL PRESSURE LOSS IN DUMP DIFFUSER

The dump diffuser is an important component in advanced annular combustor, and its performance affects greatly the fluid field and pressure loss of the combustor. This paper presents the characteristics of the total pressure loss. Experiments and numerical simulations, keeping the inlet March number of prediffuser constant ( Ma =0 20), are carried out to obtain the regularity of the total pressure loss. It varies with the relative dump gap ( δ =1 2～3 0)by changing the position of prediffuser and combustor liner, respectively. Research shows that there exists the minimum total pressure loss ( σ *=1 6%～1 75%) when relative dump gap δ is about 1 8.

Classification of Guizhou Aspidistra Plants by Near-infrared Diffuse Reflectance Spectroscopy

[Objective] This study was conducted to establish a near-infrared diffuse reflectance spectroscopy of Guizhou Aspidistra plants. [Method] Twenty three batch- es of Guizhou Aspidistra plants including A. chishuiensis, A. spinula, A. Caespitosa, A. sichuanensis, A. ebianensis, A. retusa, A. guizhouensis and A. liboensis were subjected to drying, pulverization and sieving and then directly determined for near- infrared reflectance spectrums; and the plants in this genus were classified by clus- ter analysis and principal component analysis （PCA）. [Result] The near-infrared re- flectance spectrums of the 23 batches of Guizhou Aspidistra plants showed very high similarity. The spectrums were processed by first derivative method, and the spectral range of 4 000-7 500 cm-1 was selected as the analytical range. Cluster analysis and PCA were employed to mass spectrum variables of plants in Aspidis- tra, fewer new variables became the linear combination of primary variables, and small differences between different varieties were enlarged, thereby facilitating intu- itive classification of plants in this genus. [Conclusion] Near-infrared diffuse re- flectance spectroscopy is nondestructive and rapid for determination of solid sam- pies, and provides a new method for the classification of Guizhou Aspidistra plants combined by information processing techniques.

The Study of Using Near-infrared Diffuse Reflectance Spectroscopy Rapid Identify Wheat Drought Resistance-Ⅱ

[Objective] The aim was to build an evaluation method rapidly identifying wheat drought tolerance with near infrared diffuse reflectance spectroscopy. [Method] In the research, 36 wheat varieties in 2007-2009 were chosen and drought-tolerance degrees of wheat were graded and identified according to Winter-wheat Drought Tol- erance Evaluation Technical Standards （GB/T 21127-2007）, and harvest wheat grains underwent spectrum collection, with a full-spectrum analyzer, to establish a database. [Result] Based on qualitative analysis and full-spectrum correlation research, the coef- ficient of determination （RSQ） and cross-validation coefficient of determination （1-VR） were concluded at 0.697 5 and 0.600 2, showing near-infrared diffuse reflectance spectroscopy is of significant differences among wheat varieties and of significant or extremely significant correlation with drought-tolerance indices. [Conclusion] The re- search indicates that to evaluate drought-tolerance of wheat with near-infrared diffuse reflectance spectroscopy is a rapid and feasible way, which is simple, convenient without damages on grains, and of practical values for construction wheat drought-tol- erance evaluation index system and identification of breeding materials.

Clinical features and outcomes of diffuse large B-cell lymphoma based on nodal or extranodal primary sites of origin:Analysis of 1,085 WHO classified cases in a single institution in China

Objective: To explore the clinicobiologic features and outcomes of diffuse large B-cell lymphoma(DLBCL)patients in China according to the primary site.Methods: A total of 1,085 patients diagnosed with DLBCL in National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College during a 6-year period were enrolled. Their clinical characteristics and outcomes were analyzed according to the primary site.Results: In the 1,085 patients, 679(62.6%) cases were nodal DLBCL(N-DLBCL) and 406 cases(37.4%) were extranodal DLBCL(EN-DLBCL). The most common sites of N-DLBCL were lymphonodus(64.8%), Waldeyer's ring(19.7%), mediastinum(12.8%) and spleen(2.7%), while in EN-DLBCL, stomach(22.4%), intestine(16.0%),nose and sinuses(8.9%), testis(8.4%), skin(7.9%), thyroid(6.9%), central nervous system(CNS)(6.4%), breast(5.7%), bone(3.4%), and salivary gland(2.7%) were most common. N-DLBCL patients tend to present B symptoms, bulky disease, and elevated LDH more often, while age >60 years, extranodal sites >1, Ann Arbor stage I or II, bone marrow involvement, and Ki-67 index >90% were usually seen in EN-DLBCL. The 5-year overall survival(OS) rate and progression-free survival(PFS) rate for all patients were 62.5% and 54.2%. The 5-year OS rate for patients with N-DLBCL and EN-DLBCL were 65.5% and 56.9%(P=0.008), and the 5-year PFS were57.0% and 49.0%(P=0.020). Waldeyer's ring originated DLBCL possessed the highest 5-year OS rate(83.6%) and PFS rate(76.9%) in N-DLBCL. The top five EN-DLBCL subtypes with favorable prognosis were stomach,breast, nose and sinuses, lung, salivary gland, with 5-year OS rate: 70.3%, 69.6%, 69.4%, 66.7% and 63.6%,respectively. While CNS, testis, oral cavity and kidney originated EN-DLBCL faced miserable prognosis, with 5-year OS rate of 26.9%, 38.2%, and 42.9%.Conclusions: In our study, primary sites were associated with clinical characteristics and outcomes. Compared with EN-DLBCL, N-DLBCL had better prognosis.

Diffuse axonal injury after traumatic cerebral microbleeds: an evaluation of imaging techniques

Previous neuropathological studies regarding traumatic brain injury have primarily focused on changes in large structures, for example, the clinical prognosis after cerebral contusion, intrace- rebral hematoma, and epidural and subdural hematoma. In fact, many smaller injuries can also lead to severe neurological disorders. For example, cerebral microbleeds result in the dysfunc- tion of adjacent neurons and the disassociation between cortex and subcortical structures. These tiny changes cannot be adequately visualized on CT or conventional MRI. In contrast, gradient echo sequence-based susceptibility-weighted imaging is very sensitive to blood metabolites and microbleeds, and can be used to evaluate traumatic cerebral microbleeds with high sensitivity and accuracy. Cerebral microbleed can be considered as an important imaging marker for dif- fuse axonal injury with potential relevance for prognosis. For this reason, based on experimental and clinical studies, this study reviews the role of imaging data showing traumatic cerebral microbleeds in the evaluation of cerebral neuronal injury and neurofunctional loss.

Expression and clinical value of programmed cell death-ligand 1(PD-L1)in diffuse large B cell lymphoma:a retrospective study

Background: The programmed cell death-1(PD-1)/programmed cell death-ligand 1(PD-L1) pathway inhibits the activation of T cells and plays a crucial role in the negative regulation of cellular and humoral immune responses.Diffuse large B-cell lymphoma(DLBCL) is the most common lymphoid malignancy in adults. In the present study, we aimed to detect the expression of PD-L1 in DLBCL and to analyze its relationship with prognosis.Methods: We reviewed medical records of 204 newly diagnosed DLBCL patients in Sun Yat-sen University Cancer Center between October 2005 and August 2012. The expression of PD-L1 in tumor tissues from these 204 patients was detected using immunohistochemical(IHC) assay. The expression of anaplastic lymphoma kinase(ALK), CD5,CD30, and C-Myc in tumor specimens from 109 patients was detected using IHC, and Epstein-Barr virus(EBV)-encoded RNAs(EBERs) were detected using fluorescence in situ hybridization. The Spearman method was used for correlation analysis. The Kaplan-Meier method with log-rank test was used for univariate analysis. Cox proportional hazards model was used for multivariate analysis.Results: Of the 204 patients, 100(49.0%) were PD-L1-positive in tumor cells and 44(21.6%) were PD-L1-positive in tumor microenvironment. PD-L1 expression in tumor cells and tumor microenvironment were more common in the non-germinal center B-cell-like(GCB) subtype than in the GCB subtype(P = 0.02 and P= 0.04). Patients with PD-L1 expression in tumor microenvironment were more likely to be resistant to first-line chemotherapy when compared with the patients without PD-L1 expression in tumor microenvironment(P = 0.03). PD-L1 expression in tumor microenvironment was negatively correlated with C-Myc expression(r =-0.20, P = 0.04). No correlations were detected between PD-L1 expression and the expression of ALK, CD5, and CD30 as well as EBERs. The 5-year overall survival(OS)rates were 50.0% and 67.3% in patients with and without PD-L1 expression in tumor cells(P = 0.02). PD-L1 expression in tumor cells was an independent risk predictor for OS(P < 0.01).Conclusions: PD-L1 expression is more common in the non-GCB subtype than in the GCB subtype. PD-L1 expression in tumor microenvironment has a negative correlation with C-Myc. PD-L1 positivity predicts short survival in DLBCL patients. For patients with PD-L1 expression, more strategy such as anti-PD-L1 antibody treatment should be recommended.