Atomically dispersed Fe sites on hierarchically porous carbon nanoplates for oxygen reduction reaction

Developing cost-effective,robust and stable non-precious metal catalysts for oxygen reduction reaction(ORR) is of paramount importance for electrochemical energy conversion devices such as fuel cells and metal-air batteries.Although Fe-N-C single atom catalysts(SACs) have been hailed as the most promising candidate due to the optimal binding strength of ORR intermediates on the Fe-N_(4) sites,they suffer from serious mass transport limitations as microporous templates/substrates,i.e.,zeolitic imidazolate frameworks(ZIFs),are usually employed to host the active sites.Motivated by this challenge,we herein develop a hydrogen-bonded organic framework(HOF)-assisted pyrolysis strategy to construct hierarchical micro/mesoporous carbon nanoplates for the deposition of atomically dispersed Fe-N_(4) sites.Such a design is accomplished by employing HOF nanoplates assembled from 2-aminoterephthalic acid(NH_(2)-BDC) and p-phenylenediamine(PDA) as both soft templates and C,N precursors.Benefitting from the structural merits inherited from HOF templates,the optimized catalyst(denoted as Fe-N-C SAC-950) displays outstanding ORR activity with a high half-wave potential of 0.895 V(vs.reversible hydrogen electrode(RHE)) and a small overpotential of 356 mV at 10 mA cm^(-2) for the oxygen evolution reaction(OER).More excitingly,its application potential is further verified by delivering superb rechargeability and cycling stability with a nearly unfading charge-discharge gap of 0.72 V after 160 h.Molecular dynamics(MD) simulations reveal that micro/mesoporous structure is conducive to the rapid mass transfer of O_(2),thus enhancing the ORR performance.In situ Raman results further indicate that the conversion of O_(2) to~*O_(2)-the rate-determining step(RDS) for Fe-N-C SAC-950.This work will provide a versatile strategy to construct single atom catalysts with desirable catalytic properties.

The flavonoids from Pentorum chinense Pursh.mediates ferroptosis to alleviate sorafenib-induced liver injury in BRL-3A cells

Background:Drug-induced liver damage is a severe medical issue that affects people all over the world.Sorafenib has some side effects that cause liver injury.A dietary medicinal plant called Penthorum chinense Pursh.(PCP)has hepatoprotective properties.There are currently few reports on PCP’s protective impact and mechanism against sorafenib-induced liver injury.Methods:To create a liver injury model,sorafenib was administered to BRL-3A cells.Cell viability assays,immunofluorescence tests,Western blotting,real-time quantitative PCR,and high-content imaging systems were utilized to examine PCP’s effect and mechanism.Results:In this study,PCP treatment mitigated the liver damage caused by sorafenib by enhancing cell survival,lowering lipid reactive oxygen species and malondialdehyde levels,and elevating glutathione levels.In addition,PCP can enhance the protein expression of cystine/glutamate transporter xCT and glutathione peroxidase 4,reduce iron content and alleviate mitochondrial toxicity.Further mechanism studies revealed that PCP inhibited ferroptosis by promoting the production of nuclear factor E2-related factor 2 nuclear translocation and subsequently affecting target genes(HO-1 and NQO1).Conclusion:Together,PCP regulates the nuclear factor E2-related factor 2 pathway,which helps to lessen ferroptosis brought on by sorafenib.

Progress in Diagnosis and Treatment of Small Intestinal Bacterial Overgrowth

Small intestinal bacterial overgrowth has been found to be associated with a variety of gastrointestinal disorders such as irritable bowel syndrome, inflammatory bowel disease, and, in recent years, diabetes mellitus and systemic sclerosis, among other extraintestinal diseases. Several novel diagnostic tools for small intestinal bacterial overgrowth have emerged in recent years, and several therapeutic approaches have been proposed. Therefore, it has become necessary to find an effective, safe, and simple diagnostic method and a safe treatment modality. This article provides a review of current diagnostic and therapeutic approaches to small intestinal bacterial overgrowth.

Rifaximin in the Treatment of Gastroesophageal Reflux Disease: A New Idea Based on the Relationship between Intestinal Microecology and Gastroesophageal Reflux Disease

Rifaximin in the Treatment of Gastroesophageal Reflux Disease (GERD) is a common clinical disorder, the most common symptom of which is a burning sensation behind the breastbone (heartburn) or reflux of stomach contents into the upper pharynx (acid reflux). The prevalence in China is increasing year by year, which can affect the quality of life of patients and also increase the economic burden on families and society. The pathogenesis of GERD is still unclear, and some studies suggest that intestinal microecology may be closely related to the development of GERD. Rifaximin is not readily absorbed orally and acts locally in the intestine, so it has mild adverse effects and good safety, and can be used to treat gastrointestinal diseases such as irritable bowel syndrome, traveler’s diarrhea, small intestinal bacterial overgrowth, diverticulosis, inflammatory bowel disease and hepatic encephalopathy. Therefore, this paper focuses on intestinal microecology as a possible pathogenesis of GERD and further explores the feasibility of rifaximin for the treatment of GERD.

Improved methodology for efficient establishment of the myocardial ischemia-reperfusion model in pigs through the median thoracic incision

To investigate the feasibility and effectiveness of establishing porcine ischemia-reperfusion models by ligating the left anterior descending(LAD)coronary artery,we first randomly divided 16 male Bama pigs into a sham group and a model group.After anesthesia,we separated the arteries and veins.Subsequently,we rapidly located the LAD coronary artery at the beginning of its first diagonal branch through a mid-chest incision.Then,we loosened and released the ligation line after five minutes of pre-occlusion.Finally,we ligated the LAD coronary artery in situ two minutes later and loosened the ligature 60 min after ischemia.Compared with the sham group,electrocardiogram showed multiple continuous lead ST-segment elevations,and ultrasound cardiogram showed significantly lower ejection fraction and left ventricular fractional shortening at one hour and seven days post-operation in the model group.Twenty-four hours after the operation,cardiac troponin T and creatine kinase-MB isoenzyme levels significantly increased in the model group,compared with the sham group.Hematoxylin and eosin staining showed the presence of many inflammatory cells infiltrating the interstitium of the myocardium in the model group but not in the sham group.Masson staining revealed a significant increase in infarct size in the ischemia/reperfusion group.All eight pigs in the model group recovered with normal sinus heart rates,and the survival rate was 100%.In conclusion,the method can provide an accurate and stable large animal model for preclinical research on ischemia/reperfusion with a high success rate and homogeneity of the myocardial infarction area.

新媒体时代下科普短视频在医院宣传报道中的创新应用

目的:探讨新媒体时代下科普短视频在医院宣传报道中的创新应用。方法:通过对北京市属5所医院在抖音平台上发布的科普短视频进行数据挖掘和分析,数据包括视频总数、观看次数、点赞数、评论数和分享数;运用聚类分析方法对短视频类型进行分类;利用关键词提取和文本分析技术对短视频主题进行分类;采用内容分析法对短视频表现形式进行分析。结果:专业领域科普类短视频占比最大,观看、点赞、评论和分享数均较高;心血管科普和眼科科普主题的关注度和受众需求指数最高;动画和实际操作这两种表现形式在传播效果和受众接受度方面表现出色。结论:不同类型、主题和表现形式的科普短视频在传播过程中均具有一定的优势,需要充分发挥其特点以提高传播效果。医疗机构在制作科普短视频时应关注受众关心的主题,提高其关注度和受众需求;同时,创新表现形式有助于提高传播效果和受众接受度。

神奇“魔法条”之新冠病毒的快速检测

胶体金作为商业化的即时检验POCT(point-of-care test)免疫层析技术中最广泛的标记物之一,具有显著的颜色特征,后期无需可视化改造,且形态稳定、环境友好。本文试纸条制作过程简单,不需要大型贵重仪器。采用柠檬酸三钠还原氯金酸制备胶体金,将胶体金标记在新冠病毒的核衣壳N蛋白抗体上,通过在免疫层析试纸条可视区形成类似三明治结构的抗体-抗原-抗体夹心复合物,并以此复合物的红色检测线作为新冠病毒的定性分析依据。该检测方法裸眼可测、操作简单、且快速(10 min)、灵敏(检测限为0.5 ng∙mL^(−1))、低成本(每条不超过5元)。实验过程可以引导学生体验生命体系中抗原抗体相互作用引发的特异性生命化学反应,激发学生对化学、生物、生命科学和纳米材料等学科相互融合的可视化快检技术的浓厚研究兴趣。

Deep learning-based inpainting of saturation artifacts in optical coherence tomography images

Limited by the dynamic range of the detector,saturation artifacts usually occur in optical coherence tomography(OCT)imaging for high scattering media.The available methods are difficult to remove saturation artifacts and restore texture completely in OCT images.We proposed a deep learning-based inpainting method of saturation artifacts in this paper.The generation mechanism of saturation artifacts was analyzed,and experimental and simulated datasets were built based on the mechanism.Enhanced super-resolution generative adversarial networks were trained by the clear–saturated phantom image pairs.The perfect reconstructed results of experimental zebrafish and thyroid OCT images proved its feasibility,strong generalization,and robustness.

Diagnostic and prognostic value of minor elevated cardiac troponin levels for percutaneous coronary intervention-related myocardial injury:a prospective,single-center and double-blind study

Cardiac troponin-I （cTnI） and -T （cTnT） are sensitive and specific markers of myocardial injury. However, the role of increased cTnI and cTnT in percutaneous coronary intervention （PCI）-related myocardial injury remains controversial. In this prospective, single-center and double-blind study, we aimed to determine the diagnostic and prognostic value of cTnI as well as cTnT （cTns） in PCI-related myocardial injury in a Chinese population. A total of 1,008 patients with stable angina pectoris and non-ST-segment elevation acute coronary syndrome were recruited. The levels of cTnI and cTnT were examined before and after PCI. All patients were followed up for 26± 9 months to observe the incidence of major adverse cardiac events （MACEs）. Our results showed that post- PCI cTnI and/or cTnT levels were increased to more than the 99^th percentile upper reference limit （URL） in 133 （13.2%） patients, among which 22 （2.2%） were more than 5 × 99^th percentile URL. By univariate analysis, an elevation in cTns after PCI was not an independent predictor of increased MACEs, HR 1.35 （P = 0.33, 95% CI： 0.74-2.46）. In conclusion, our data demonstrate that the incidence of PCI-related myocardial injury is not common in a Chinese population and minor elevated cTns levels may not be a sensitive prognostic marker for MACEs.

Sedimentary environment controls on the accumulation of organic matter in the Upper Ordovician Wufeng–Lower Silurian Longmaxi mudstones in the Southeastern Sichuan Basin of China

The Upper Ordovician–Lower Silurian mudstones(including the Wufeng, Guanyinqiao and Longmaxi Formations) in the Sichuan Basin are some of the most important shale gas plays in China. In order to enhance our understanding of the process of formation of organic carbon up to 10%, optical, microscopy and geochemical methods have been used to investigate the petrographic and geochemical characteristics of the formation. Firstly, three mudstone lithofacies were identified based on a wide variety of mudstone laminations. These are:(a) indistinctly laminated mudstone;(b) parallellaminated mudstone; and(c) nonparallel-laminated mudstone. Then, combining with the evidence from depocenter migration, Th/U ratios and total organic carbon, the abundant organo-minerallic fabrics suggest that organic carbon was preferentially deposited and preserved in anoxic, low energy and stagnant water conditions during deposition of the Wufeng and Longmaxi Formations. On the contrary, the Guanyinqiao Formation with poor organic carbon was deposited in oxic and high-energy water conditions.

Effect of berberine on hyperglycaemia and gut microbiota composition in type 2 diabetic Goto-Kakizaki rats

BACKGROUND A recent investigation showed that the prevalence of type 2 diabetes mellitus(T2DM)is 12.8%among individuals of Han ethnicity.Gut microbiota has been reported to play a central role in T2DM.Goto-Kakizaki(GK)rats show differences in gut microbiota compared to non-diabetic rats.Previous studies have indicated that berberine could be successfully used to manage T2DM.We sought to understand its hypoglycaemic effect and role in the regulation of the gut microbiota.AIM To determine whether berberine can regulate glucose metabolism in GK rats via the gut microbiota.METHODS GK rats were acclimatized for 1 wk.The GK rats were randomly divided into three groups and administered saline(Mo),metformin(Me),or berberine(Be).The observation time was 8 wk,and weight,fasting blood glucose(FBG),insulin,and glucagon-like peptide-1(GLP-1)were measured.Pancreatic tissue was observed for pathological changes.Additionally,we sequenced the 16S rRNA V3-V4 region of the gut microbiota and analysed the structure.RESULTS Compared with the Mo group,the Me and Be groups displayed significant differences in FBG(P<0.01)and GLP-1(P<0.05).A significant decrease in weight and homeostatic model assessment-insulin resistance was noted in the Be group compared with those in the Me group(P<0.01).The pancreatic islets of the Me-and Be-treated rats showed improvement in number,shape,and necrosis compared with those of Mo-treated rats.A total of 580 operational taxonomic units were obtained in the three groups.Compared to the Mo group,the Me and Be groups showed a shift in the structure of the gut microbiota.Correlation analysis indicated that FBG was strongly positively correlated with Clostridia_UCG-014(P<0.01)and negatively correlated with Allobaculum(P<0.01).Body weight showed a positive correlation with Desulfovibrionaceae(P<0.01)and a negative correlation with Akkermansia(P<0.01).Importantly,our results demonstrated that Me and Be could significantly decrease Bacteroidetes(P<0.01)and the Bacteroidetes/Firmicutes ratio(P<0.01).Furthermore,Muribaculaceae(P<0.01;P<0.05)was significantly decreased in the Me and Be groups,and Allobaculum(P<0.01)was significantly increased.CONCLUSION Berberine has a substantial effect in improving metabolic parameters and modulating the gut microbiota composition in T2DM rats.

Defect of SLC38A3 promotes epithelial-mesenchymal transition and predicts poor prognosis in esophageal squamous cell carcinoma

Objective: Solute carrier family 38(SLC38 s) transporters play important roles in amino acid transportation and signaling transduction. However, their genetic alterations and biological roles in tumors are still largely unclear.This study aimed to elucidate the genetic signatures of SLC38 s transporters and their implications in esophageal squamous cell carcinoma(ESCC).Methods: Analyses on somatic mutation and copy number alterations(CNAs) of SLC38 A3 were performed as described. Immunohistochemistry(IHC) assay and Western blot assay were used to detect the protein expression level. MTS assay, colony formation assay, transwell assay and wound healing assay were used to explore the malignant phenotypes of ESCC cells. Immunofluorescence assay was used to verify the colocalization of two indicated proteins and immunopreciptation assay was performed to confirm the interaction of proteins.Results: Our findings revealed that SLC38 s family was significantly disrupted in ESCC, with high frequent CNAs and few somatic mutations. SLC38 A3 was the most frequent loss gene among them and was linked to poor survival and lymph node metastasis. The expression of SLC38 A3 was lower in tumor tissues compared to that in normal tissues, which was also significantly associated with worse clinical outcome. Further experiments revealed that depletion of SLC38 A3 could promote EMT in ESCC cell lines, and the interaction of SLC38 A3 and SETDB1 might lead to the reduced transcription of Snail. Pharmacogenomic analyses demonstrated that fifteen inhibitors were showed significantly correlated with SLC38 A3 expression.Conclusions: Our investigations have provided insights that SLC38 A3 could act as a suppressor in EMT pathway and serve as a prognostic factor and predictor of differential drug sensitivities in ESCC.

Diffuse large B-cell lymphoma arising from follicular lymphoma with warthin’s tumor of the parotid gland-immunophenotypic and genetic features: A case report

BACKGROUND Warthin’s tumor(WT)is composed of several cysts that are lined with tall,bilayered oncocytic columnar cells and lymphoid stroma.Within WT,the two components rarely transform into carcinoma or lymphoma,and when it does,carcinoma is the most common type.Approximately 28 cases of lymphoma with WT have been reported,most of which were non-Hodgkin lymphomas,and only a few cases were Hodgkin lymphomas.In the present report,we studied a case of diffuse large B cell lymphoma(DLBCL)arising from follicular lymphoma(FL)with WT in the parotid gland and its immunophenotypic and genetic features.CASE SUMMARY A 67-year-old man presented with a slowly enlarging right cheek mass for 12 years,and the mass began to change in size over a 2-mo time period.Over time,the patient felt mild local pain and right cheek discomfort.His medical history included a hepatitis B virus infection for 20 years and 30 years of smoking.Gross examination of the excised specimen showed a gray-red and gray-white appearance and a soft texture lobulated external surface neoplasm that measured 9 cm×8 cm×7 cm and was well circumscribed by relative normal parotid gland tissue.In cross section,the cut surfaces of the neoplasm were multicystic and had a homogeneous scaly appearance.A small fluid was discovered in the cyst.Bilateral oxyphilic,cuboidal or polygonal epithelium cells and lymphoid intraparenchymal components were observed.Many medium-to large-sized lymphoid cells were observed diffusely in part of the neoplasm,and a few secondary lymphoid follicles were observed at the center or edge of the neoplasm.Immunohistochemical staining showed that the columnar oncocytic cells were positive for AE1/AE3;neoplastic cells located in coarctate follicular were positive for CD20,Pax-5,bcl-2 and bcl-6;and the adjacent diffusely medium-to large-sized lymphoid cells were positive for Pax-5,bcl-6,CD20,MUM-1,bcl-2 and CD79a.The bcl-6(3q27)break-apart rearrangement was observed,and an Epstein Barr virus test was negative in the tumor cells.The patient survived 6 months after being diagnosed without any treatment.CONCLUSION WT-associated lymphoma is a very rare neoplasm in the parotid gland.Most cases are B cell non-Hodgkin lymphomas and involve middle-age and older males.This case highlights the extremely rare association of DLBCL arising from FL with WT and the importance of deliberate evaluation of the WT intraparenchymal stroma.Molecular detection techniques have potential advantages in the diagnosis of lymphoma with WT.

SBA-15 Modified Carbon Paste Electrode for Rapid cTnI Detection with Enhanced Sensitivity

A novel electrochemical immunoassay for cardiac troponin Ⅰ （cTnI） combining the concepts of the dual monoclonal antibody ＂sandwich＂ principle, the silver enhancement on the nano-gold particle, and the SBA-15 mesoporous modified carbon paste electrode （SBA-MCPE） is described. Four main steps were carried out to obtain the analytical signal, i.e., electrode preparation, immunoreaction, silver enhancement, and anodic stripping voltammetric detection. A linear relationship between the anodic stripping peak current and concentration of cTnI from 0.5 to 5.0 ng/mL and a limit of detection of 0.2 ng/mL of cTnI were obtained.

Effects of regenerated tissue extracts after liver injury on the proliferation,differentiation,migration and invasion of SK-HEP1 cells

Objective: To study the effects of regenerated tissue extracts after liver injury on the proliferation, differentiation, migration and invasion of SK-HEP1 cells. Methods: Regenerated tissue extracts after liver injury were used to induce SK-HEP1 cells after enrichment, their effects on the proliferation, differentiation, migration and invasion of SK-HEPI cells were observed through in vitro cell culture, MTT, flow cytometry and transwell assays. Results:In response to the action of regenerated tissue extracts after liver injury, SK-HEP1 cells were blocked in G_0/G_1 phase, their growth rate was distinctly reduced. The number of SK-HEP1^(-fj)colonies decreased. The migration ability of SK-HEPI cells showed a decreased trend on day7 and day 11 after induction. SK-HEPl's invasion ability clearly decreased on days 7 and11 after induction, especially on day 7. Conclusions: To a certain extent, regenerated tissue extracts after liver injury can inhibit the proliferation, differentiation, migration and invasion of hepatoma cells, showing an important potential of being a differentiating agent for the treatment of liver cancer.

SUCCESSFUL RESECTION OF CARDIAC ANGIOSARCOMA COMBINED WITH RIGHT CORONARY ARTERY BYPASS GRAFTING

ANGIOSARCOMA is the most common primary malignant cardiac tumor. Until recently, the diagnosis is often not established until the tumor is advanced with vital cardiac structure involved or distal metastasis, mainly because the symptoms are initially nonspecific. The natural history of cardiac angiosarcoma is characterized by a short clinical course and a fatal outcome. Surgical resection remains the preferential therapy for palliation or cure, where as irradiation and chemotherapy have only limited use. We herein reported a successful radical resection of cardiac angiosarcoma with concomitant reconstruction of right coronary artery, tricuspid leaflet, and atrial wall. The literature on cardiac angiosarcomas is reviewed extensively, with emphasis on presentation and surgical

No association between thrombospondin-4 A387P polymorphism and acute coronary syndrome in Chinese Han population

Objective： The thrombospondin-4 （TSP-4） gene G29926C （A387P） polymorphism was recently reported to be associated with an increased risk of MI （myocardial infarction） in American population. However, several subsequent studies produced controversial findings. The aim of this study was to explore the possible association between TSP-4 A387P polymorphism and ACS （acute coronary syndrome） in Chinese Han population. Methods：A case-control study including 412 patients with ACS and 337 controls free from CAD （coronary artery disease） was conducted. TSP-4 A387P polymorphism was determined by PCR （polymerase chain reaction） and RFLP （restriction fragment length polymorphism） analysis. Results：Slightly decreased frequency of GC genotype was observed in patients with ACS, compared with controls（5.3% vs. 7.1%）, but the difference did not reach statistical significance （P = 0.31 ）. Similarly, the prevalence of C allele was 2.7% and 3.6% for ACS and control groups, respectively （P = 0.32）. None of homozygote was detected for C allele. Further analyses in subjects subgrouped according to sex and age also showed no association of TSP-4 A387P polymorphism with ACS. Furthermore, after adjustment for conventional risk factors by multiple logistic regression analysis, the carrier prevalence of C allele did not differ significantly between ACS and control groups （OR = 0.85; 95% CI：0.45-1.59; P = 0.60）. Conclusion：The present study suggested that the TSP-4 A387P variant showed a low prevalence compared with western populations and failed to associate with an altered risk of ACS in Chinese Han population. The findings further supplement experimental data for TSP-4 gene study of coronary disease.

叶生态特征及其相关性对下垫面热效应的生态权衡

为研究植物叶性状及其相关关系对城市下垫面热效应的响应及其生态权衡策略,以生长在6种典型城市下垫面(沥青、水泥、荷兰砖、大理石、嵌草砖和自然地表)环境中的3种常见绿化树种(洋白蜡、国槐和臭椿)为研究对象,测定其叶功能性状指标。结果表明:比叶面积、叶绿素含量、气孔面积、气孔开度及叶氮磷比均随着环境地表温度的增大总体上呈现先增加、后减小的趋势,城市下垫面从大到小依次为嵌草砖地表、自然地表、大理石地表、水泥地表、荷兰砖地表、沥青地表。而叶干物质含量、叶组织密度、气孔密度及叶脉密度、叶氮含量、叶磷含量则呈相反的变化规律,城市下垫面从大到小依次为沥青地表、荷兰砖地表、水泥地表、大理石地表、自然地表、嵌草砖地表。叶性状间表现了一定的相关关系,其中,比叶面积与叶干物质含量、叶组织密度与气孔密度间呈极显著的负相关关系(P <0. 01),与叶氮含量、叶磷含量呈显著的正相关关系(P <0. 01)。叶干物质含量与叶组织密度、叶脉密度和叶氮含量存在极显著的正相关关系(P <0. 01)。气孔密度与气孔面积、气孔开度间存在显著的负相关关系(P <0. 05),而与叶脉密度间存在显著的正相关关系(P <0. 05)。气孔面积与叶氮含量间存在显著的正相关关系(P <0. 05),与叶组织密度呈极显著的正相关关系(P <0. 01)。随着地表温度的升高,植物叶性状间的相关性呈现先增、后减的趋势,小幅度升温总体上有利于加强叶功能性状间的相关性,而温度过高则明显降低其相关关系。城市生态系统中,植物叶片具有低的比叶面积、叶绿素含量、气孔面积、气孔开度和叶氮磷比,高的叶干物质含量、叶组织密度、气孔密度、叶氮含量和叶磷含量,进一步验证了城市生态系统中叶经济谱的存在,并在该谱系中属于"快速投资-收益"型。

延迟焦化装置回炼苯乙烯焦油研究

针对苯乙烯焦油处理过程环保压力较大的问题,将苯乙烯焦油送进延迟焦化装置进行回炼。结果表明:延迟焦化装置在给水冷焦期间回炼苯乙烯焦油,会使冷切焦水变色,且除焦期间有异味,故苯乙烯焦油不适合在冷焦期间回炼;在焦炭塔生产期间进行苯乙烯焦油回炼的方法可行,但回炼苯乙烯焦油会对焦化装置分馏塔侧线产生影响,需要控制回炼量及回炼时间,做好工艺优化操作及设备计划性维修,定期对延迟焦化装置各个产品、冷切焦水、含硫污水中苯乙烯焦油的含量进行分析。通过不断优化工艺和设备条件,解决了回炼过程中设备、管线堵塞的问题,回炼后装置运行较为平稳。通过回炼,成功将苯乙烯焦油分解到延迟焦化装置的产品中。

基于文本挖掘的北京市属公立医院负面舆情研究

目的本研究基于文本挖掘与主题建模的方法对北京市属公立医院负面舆情进行分析。方法收集北京市22家市属公立医院2021年1月1日至12月31日在主流网媒平台的全部负面舆情。采用Python 3.9进行文本挖掘并建立语料库,利用隐含狄利克雷分布(LDA)主题模型对语料进行聚类,并根据每个聚类的关键词解释聚类含义。结果共收集语料3083条,提取6个主题,根据关键词形成号源与资费相关问题、突发公共卫生事件相关问题、等待时间与服务可及性问题、服务态度与就诊流程体验问题、患者入院手术体验与预后问题等5类问题。结论公立医院的负面舆情是反映社情民意的重要信息来源。通过对负面舆情的文本挖掘研究,可以有效发现管理漏洞,提出改进措施,从而提升医院舆情管理工作,改善医疗服务工作。