Ventricular Septal Crypts:Remnants of Spontaneous Interventricular Defect Closure?

Background:Ventricular crypts are quite a common finding during cardiac imaging,but their etiology is unclear.A possible final result of a spontaneous ventricular septal defect closure has been supposed but never investigated in earlier studies.Method:From January 1997 to December 2020,all newborns diagnosed to have a ventricular septal defect were prospectively entered in our database and those with an isolated defect were included in the study.Ventricular septal defects were classified into four types:perimembranous,trabecular muscular,inlet and outlet.A long-term follow up was performed in order to visualize the possible residual formation of a septal myocardial crypt.Results:A total of 376 isolated ventricular septal defects(314 muscular and 54 perimembranous,4 inlet,4 outlet)were detected.Follow up ranged from 1 to 23 years and showed that,among muscular type,a spontaneous closure occurred in 284(91%),26 did not close(8,28%),2 required surgical intervention(0,63%),3 were lost at follow up(0,95%).During this period,after spontaneous defect closure closure,20 crypts were found(6,4%).Conclusion:This study shows that a muscular ventricular septal defect may evolve in the 6.4%of cases in a residual septal crypt.Although septal crypts occur more frequently in patients affected by hypertrophic and hypertensive cardiomyopathy,they may also represent the evolution of a spontaneous closure of a muscular interventricular defect.

小鼠小肠类器官炎症模型的构建

目的建立体外小肠类器官培养体系,探讨脂多糖(LPS)对小肠类器官生长和炎性因子分泌的影响。方法体外无菌分离并收集C57BL/6小鼠小肠隐窝细胞团,使用类器官基质胶进行包埋,并在完全培养基的支撑下,培养形成具有小肠上皮样结构的立体多叶结构的小肠类器官。小肠类器官培养5~7 d或类器官中央区域变黑时传代,传代后3 d将小肠类器官随机分为不同质量浓度LPS组(0、150、175、200、225、250、275、300 mg/L)。在LPS诱导24 h和48 h后观察小肠类器官生长和形态特征变化;用CCK-8法检测不同时间和质量浓度LPS对小肠类器官诱导炎症后增殖活力的影响;采用酶联免疫吸附试验检测4种不同质量浓度LPS(0、175、200、225 mg/L)在不同时间对类器官培养上清液中粒细胞-巨噬细胞集落刺激因子(GM-CSF)、白细胞介素(IL)-1α、IL-6、IL-10水平的影响。结果初步构建了小鼠小肠类器官培养体系。不同时间和质量浓度LPS作用小肠类器官诱导炎症后,通过形态学观察到小肠类器官会有不同程度的膨胀和内腔凋亡现象的发生,受损的肠上皮中隐窝或肠干细胞的增殖分化和出芽数量也受到不同程度的抑制。小肠类器官在175~225 mg/L的LPS诱导24 h和48 h后,其增殖活力呈现不同程度的降低(P<0.05),但细胞活力仍大于50%。200 mg/L和225 mg/L的LPS诱导24 h和48 h后,IL-1α、IL-6和GM-CSF水平部分升高(P<0.05);200 mg/L的LPS诱导24 h和48 h后,IL-10水平降低(P<0.05)。结论本研究初步构建了不同质量浓度和时间的LPS诱导小肠类器官体外肠道炎症损伤模型,为今后肠道疾病的机制研究和有效药物的筛选提供了更为可靠的研究平台。

从“玄府-隐窝”视域辨治溃疡性结肠炎肠屏障受损

“玄府”作为中医藏象理论的微观结构遍布于人体各部,急性溃疡性结肠炎微观病变表现为结肠隐窝脓肿甚至结构紊乱。其湿热蕴结大肠,肠道因实而闭的发病特点与“玄府”贵开忌阖、贵通忌闭的理念契合。肠道隐窝机械屏障与黏液屏障功能与“玄府”推陈出新、气液宣通的特点有共通之处,可为肠“玄府”理论提供形态学依据。清开玄府法能够抑制湿热郁腐之物蕴结、肠道郁闭不通导致的肠“玄府闭阖”状态,推动“玄府-隐窝”学说在治疗溃疡性结肠炎早期隐窝病变的指导作用和理论支撑。

鼻内镜下泪前隐窝入路术式及柯陆入路术式治疗对上颌窦内翻性乳头状瘤患者机体应激指标的影响与安全性研究

目的 探讨鼻内镜下泪前隐窝入路术式及柯陆入路术式治疗对上颌窦内翻性乳头状瘤(Inverting Papilloma, IP)患者机体应激指标的影响与安全性。方法 前瞻性随机选取2019年4月—2023年8月三明市第二医院确诊为上颌窦IP的120例患者为研究对象,按照随机数表法分为两组,每组60例,对照组行鼻内镜下柯陆入路术式处理,观察组行鼻内镜下泪前隐窝入路术式治疗,比较两组的手术基础指标、不同手术阶段的机体应激指标、术后并发症及复发情况。结果 观察组手术时间、术中出血量、术后鼻通气时间、住院时间均优于对照组,差异有统计学意义(P均<0.05)。术后1 d,观察组肾上腺素、皮质醇、转化生长因子β1检测值均低于对照组,差异有统计学意义(P均<0.05)。观察组术后并发症总发生率(3.33%)低于对照组(13.33%),差异有统计学意义(χ^(2)=3.927,P=0.047)。两组术后半年的复发率比较,差异无统计学意义(P>0.05)。结论 鼻内镜下泪前隐窝入路术式、柯陆入路术式用于上颌窦IP患者的治疗远期疗效相当,但前者还具有近期处理效果较好,可减轻机体应激反应,减少并发症发生等优势。

骆驼刺提取物对脂多糖诱导的IEC-6细胞损伤模型NLRP3炎症小体及相关细胞因子的影响

目的研究骆驼刺提取物(Alhagi pseudalhagi(M.B.)Desv.Extract,APE)对脂多糖诱导的大鼠小肠隐窝上皮细胞(Intestinal epithelial cell,IEC-6)损伤模型NLRP3炎症小体及相关细胞因子的影响。方法培养IEC-6细胞,将其分为空白组、模型组、APE低、中、高浓度组,用1.0μg/mL的脂多糖(Lipopolysaccharide,LPS)诱导建立细胞炎症损伤模型,APE(低、中、高浓度:15、25、35μg/mL)干预后采用CCK-8法检测细胞的存活率,通过ELISA试剂盒检测炎症因子IL-1β、IL-18、TNF-α的分泌水平。蛋白质印迹法(WB)检测核苷酸结合寡聚化结构域样受体蛋白3(Nucleotide-binding oligomerization domain-like receptor protein 3,NLRP3)炎症小体信号通路5个关键蛋白:NLRP3、半胱氨酸天冬氨酸蛋白酶1(Cystein-asparate protease-1,Caspase-l)、凋亡相关斑点样蛋白(Apoptosis-associated speck-like protein containing a CARD,ASC)及抗凋亡蛋白Bcl-2(Anti-apoptosis Protein Bcl-2)和Bcl-xl(Anti-apoptosis Protein Bcl-xl)表达。结果与空白组比较,模型组IEC-6细胞的存活率降低,NLRP3、Caspase-1、ASC蛋白表达水平升高,抗凋亡蛋白Bcl-2、Bcl-xl的表达水平降低,促炎因子IL-1β、IL-18和TNF-α的分泌水平升高,差异有统计学意义(P<0.05)。与模型组比较,APE低、中、高浓度组细胞存活率升高,35μg/mL APE组IEC-6细胞的NLRP3、Caspase-1、ASC蛋白相对表达水平降低,抗凋亡蛋白Bcl-2、Bcl-xl的表达水平升高,差异有统计学意义(P<0.05)。中、高浓度的APE能够抑制炎症因子分泌,25μg/mL APE对IL-1β、IL-18、TNF-α炎症因子分泌水平抑制率分别为31.60%、31.19%和31.09%(P<0.05)。结论骆驼刺提取物通过提高抗凋亡蛋白Bcl-2、Bcl-xl的表达水平,下调NLRP3炎症小体组成成分以及促炎因子IL-1β、IL-18和TNF-α分泌,从而抑制NLRP3炎症小体组装和激活,实现缓解LPS对IEC-6细胞的损伤。

Crypt-JDBC模型:洋葱加密算法的优化改进

CryptDB是一种典型的密文存储技术,它根据运算操作语义使用洋葱加密算法将SQL语句改写到不同的洋葱密文列,从而仅暴露数据的部分属性即可执行查询任务。针对洋葱加密算法的不足之处提出了一种名为Crypt-JDBC的改进模型:(1)鉴于洋葱层数多,且相邻层功能差异大,新模型把洋葱列分为主列与辅助列,并压缩洋葱层的改进方法(主列使用双向算法可还原明文,辅助列使用单向算法提供属性,保证安全性);(2)鉴于等值连接算法复杂低效,新模型通过简化一个关键模块(差异性转换)来降低复杂度;(3)鉴于列名的明文、密文名称对应性弱,新模型重新设计了明密文列名称的对应关系,减少了上下文信息,加强了密钥整体性。实现了Crypt-JDBC模型,用JDBC替换中间件软件MySQL-Proxy。实验结果表明,该模型具有较高的执行效率。

Linux加密文件系统:Crypt-FS

随着便携式计算设备的普及，保存数据的存储设备失窃或遗失的可能性增大。在这种情况下，能够保证敏感数据不被泄露的唯一方案是使用数据加密技术。相对于其它加密方式，使用加密文件系统对用户透明、可靠，有着不容忽视的优势。文章在Linux 2.4操作系统上设计和实现了一个加密文件系统——Crypt-FS，并对其进行了介绍。

Cancer and age related colonic crypt deficiencies in cytochrome c oxidase Ⅰ

AIM: To investigate whether defi ciency of expressionof cytochrome c oxidase I (CcOI) in colonic crypts is associated with colon cancer.METHODS: The pattern and level of expression of CcOI in non-neoplastic colonic crypts,and in dysplastic tissues,was assessed using standard immunohis-tochemical methods.Biopsies were obtained from individuals undergoing colonoscopies for screening purposes or for a medically indicated reason.Tissue samples were also obtained from surgical colonic resections.Samples from resections were taken from colonic mucosa 1 and 10 cm from tumors and from the tumors themselves.Samples were evaluated for frequency of crypts with reduced or absent expression of CcOI.In most crypts the loss was apparent throughout the entire crypt,while in a small minority the loss was segmental.The strong immunoreactivity using this monoclonal antibody makes the scoring unambiguous.The percent of crypts with reduced or absent expression of CcOI or (infrequent) segmented loss of expression was then calculated.Data analyses were performed using SPSS statistical package 17.0.RESULTS: The average frequency of CcOI deficient crypts (CcOI-DC) is low in individuals between 20 and 39 years of age,with 0.48% ± 0.40% CcOI-DC for women and 1.80% ± 0.35% for men.CcOI-DC increases after age 40 years,so that between the ages of 40 and 44 years the average frequency of CcOI- DC goes up to 5.89% ± 0.84% in women and 2.15% ± 1.27% in men.By 80-84 years of age,the average frequency of CcOI-DC goes up in women to 15.77% ± 0.97% and in men to 22.6% ± 0.65%.The increases in CcOI-DC from ages 40-44 years compared to 80-84 years in women and men are significantly different with P < 0.01.For women over age 60 years,deficiency of CcOI expression is greater in those women who have had a cancer in their colon.The frequency of CcOI-DC,measured in men,increased in tissues adjacent to colon cancer,being 4.03% ± 0.27% in individuals free of neoplasia in the age range 55-64 yearsand 14.13% ± 0.35% in resected histologically normal tissue of men with cancer in the same age range,P < 0.001.Similar signifi cant differences were noted in older age ranges.The frequency of CcOI-DC crypts in the cecum and sigmoid colon of an individual are signifi cantly correlated,with an R2 = 0.414 for women and R2 = 0.528 for men,P < 0.001.This suggests that the factors determining the level of CcOI deficiency act throughout the colon.Most defective crypts are in clusters of two or more,a likely consequence of crypt fission.In the non-neoplastic margins of cancers,crypts are frequently defi cient for CcOI,and such crypts may appear in large clusters,some containing more than 100 defi cient crypts.CcOI defi ciency is also apparent in colon cancers and sometimes involves a large section of the tumor.Overall,CcOI deficient cells can be visualized in segments of crypts,in whole crypts that increase in frequency with age,in crypts undergoing f ission,in clusters of crypts where the clusters increase in size with age,in increased frequency near tumors,in large clusters in the intimate margins of tumors,and in the tumors themselves.There is no clear dividing line between early stages that can be considered aspects of aging and later stages that can be considered aspects of the progression to cancer.This ambiguity may re ect a rather general situation leading to adult cancer where the early stages of cellular change appear to be relatively innocuous features of the aging process but over decades may evolve into malignancy.CONCLUSION: CcOI defi cient crypts increase in frequency with age,and clusters of defi cient crypts are associated with,and may give rise to,colon cancer.

APC and K-ras gene mutation in aberrant crypt foci of human colon

AIM To study the genetic alteration in ACF andto define the possibility that ACF may be a veryearly morphological lesion with molecularchanges, and to explore the relationshipbetween ACF and colorectal adenoma evencarcinoma.METHODS DNA from 35 CRC, 15 adenomas, 34ACF and 10 normal mucus was isolated by meansof microdissection. Direct gene sequencing of K-ras gene including codon 12, 13 and 61 as well asthe mutation cluster region (MCR) of APC genewas performed.RESULTS K-ras gene mutation frequency inACF, adenoma and carcinoma was 17.6% (6/34), 13.3% (2/ 15), and 14.3% (5/ 35)respectively, showing no difference ( P > 0.05)in K-fas gene mutation among three pathologicprocedures. The K-ras gene mutation inadenoma, carcinoma and 4 ACF restricted incodon 12 (GGT→GAT), but the other 2 mutationsfrom ACF located in codon 13 (GGC→GAC). K-res gene mutation was found more frequently inolder patients and patients with polypoidcancer. No mutation in codon 61 was found in thethree tissue types. Mutation rate of APO gene inadenoma and carcinoma was 22.9% (8/35) and26.7% (4/ 15), which was higher than ACF(2.9%) (P < 0.05). APC gene mutation incarcinoma was not correlated with age ofpatients, location, size and differentiation oftumor.CONCLUSION ACF might be a very earlymorphological lesion in the tumorogenesis ofcolorectal tumor. The morphological feature andgene mutation status was different in ACF andadenoma. ACF is possibly putative'microadenoma' that might be the precursor ofadenoma. In addition, the development of asubgroup of colorectal carcinomas mightundergo a way of 'normal epithelium→ ACF→carcinomas'.

Crypt abscess-associated microbiota in inflammatory bowel disease and acute self-limited colitis

AIM:To evaluate whether crypt abscesses frominflammatory bowel disease(IBD)patients containbacteria and to establish their nature.METHODS:We studied 17 ulcerative colitis patients,11 Crohn's disease patients,7 patients with acute selflimited colitis(ASLC)and normal colonic biopsies from5 subjects who underwent colonoscopy for colon cancer screening.A fluorescent in situ hybridization techniquewas applied to colonic biopsies to assess the microbiotacomposition of the crypts and crypt abscesses.RESULTS:Crypts colonized by bacteria were observedin 42.9%and 3.6%of ASLC and IBD patients,respectively(P=0.019).Crypt abscesses colonized bybacteria were observed in 28.6%and 0.0%of ASLCand IBD patients,respectively(P=0.035).CONCLUSION:These results do not support thehypothesis that crypt abscesses in IBD are the resultof localized dysbiosis arising from persistence of livingbacteria colonizing the crypts.

Aberrant crypt focus and fragile histidine triad protein in sporadic colorectal carcinoma

AIM:To characterize aberrant crypt focus (ACF) in adjoining mucosa in sporadic colorectal carcinoma and to evaluate fragile histidine triad (Fhit) protein and Ki67. METHODS:ACF was identified grossly and classified histologically in 75 resected specimens. ACF was typed into hyperplastic ACF (HACF) and dysplastic ACF (DACF). Sections of ACF, carcinoma and normal colonic mucosa as control were studied for Fhit and Ki67 expressions by immunohistochemistry and were grouped according to staining intensity and the number of positive stained cells observed in different histological groups. Comparison was done between the different groups by Pearson's χ 2 test and γ test for the ordinal data. P value < 0.05 was considered as significant.RESULTS:Age range was 40 to 86 years in males (mean = 43.36) and 45 to 70 years in females (mean = 56). HACF was identified in all cases studied in the non-tumorous colonic mucosa; ACF was observed as non-contiguous scattered foci, which supports the hypothesis of acquisition of single focus monoclonality by colonic epithelial cells in tumor generation. Twenty-four (32%) had DACF and were observed as closure to carcinoma foci. Intensity of Fhit expression:(1) HACF 40% exhibited strong intensity, similar to normal, moderate in 36% and weak in 24%; (2) DACF strong in 25%, moderate in 37.5% and weak in 37.5%; and (3) carcinoma negative in 16%, strong in 43% and moderate and weak in 28.5% each. Significant difference was observed in intensity of the Fhit protein expressions by HACF and DACF (P < 0.05). Tumor in older patients showed a stronger Fhit intensity compared to younger patients (P = 0.036). Vegetarian diet intake and nonsmokers showed stronger Fhit intensities. Advanced stage tumor, non-vegetarian diet and younger age was associated with loss of Fhit protein. Ki67 positivity was an extended crypt pattern in HACF and DACF showed extension up to the neck region of the crypts and surface epithelium. Carcinomas showed a marked increase in Ki67 expression (P < 0.05). Fhit protein had an inverse association with Ki67 expression. CONCLUSION:Weaker Fhit intensity was associated with smoking, non-vegetarian diet intake and increasing Ki67 expression. Loss of Fhit protein expression is possibly influenced by environmental factors like smoking and non-vegetarian diet intake.

CryptDB密文数据库系统并行方案研究

加密数据库对隐私数据的加密存储保护是解决当前互联网中用户隐私数据泄露的一种可行方案。鉴于互联网中每日产生的用户隐私数据规模巨大,传统的串行计算会导致隐私数据的加密存储时间消耗较长。为提高加密存储等数据处理的速度,将MapReduce并行框架与Crypt DB密文数据库系统进行有机结合,设计并实现了Crypt DB密文数据库系统并行加密和分布式存储的方案。并行方案采用任务调度算法、文件分割算法来提高其并行性和可控性,通过重写MapReduce框架中的Map方法来实现Crypt DB密文数据库系统的并行加密和分布式存储。基于由1个Master节点、3个Crypt DB节点和3个My SQL服务器构成的实验平台,进行了并行方案的实验验证及其性能分析。实验结果表明,所构建的并行方案在3个Crypt DB节点集群中的加速比可达到2.51,加密和存储时间节省了60.2%,可用于大规模关系数据的加密存储。

Azoxymethane-induced rat aberrant crypt foci:Relevance in studying chemoprevention of colon cancer

结肠癌的致病包含顺序并且多走与定义癌症前期的中间人开始到一个癌的状态的上皮细胞的前进。异常地窟 foci (ACF ) 在试验动物和人在冒号致癌作用期间代表最早可看作是相同的中间的癌前期损害。ACF 被冒号特定的致癌物容易在啮齿类动物导致并且能被用来进一步了解冒号致癌作用的过程。为超过二十年，自从它的第一发现， azoxymethane (AOM ) 导致了啮齿类动物 ACF 在屏蔽各种各样的反致癌物和致癌物用作代理人简历标记。几饮食的成分和 phytochemicals 用 ACF 系统为他们的结肠癌 chemopreventive 功效被测试了。在以理解他们的分子的组成定义并且精制 ACF 有实质的努力，并且这个领域里的广泛的研究当前在进行中。在 chemoprevention 研究，导致 AOM 的老鼠 ACF 作为简历标记很成功，并且提供了数据的几标准化分析。有几研究，报导了然而，那个 ACF 数据不相关到实际冒号肿瘤结果并且在那里因此有作为简历标记是关于他们的角色的歧义。这微型评论的范围是在结肠癌 chemoprevention 研究作为简历标记提供导致 AOM 的老鼠 ACF 的珍贵卓见和限制。动力学的角色和 ACF 的生物异质在在 chemoprevention 研究作为简历标记理解他们是关键的。

Relationship of human rectal aberrant crypt foci and formation of colorectal polyp:One-year following up after polypectomy

AIM:To clarify the relationship of human rectal aberrant crypt foci and formation of colorectal polyp.METHODS:Eighty-nine subjects were recruited from the population of Japanese individuals who underwent polypectomy at Yokohama City University Hospital.All patients had baseline adenomas removed at year 0 colonoscopy.Aberrant crypt foci(ACF) were defined as lesions in which the crypts were more darkly stained with methylene blue than normal crypts and had larger diameters,often with oval or slit-like lumens and a thicker epithelial lining.RESULTS:A total of 366 ACFs were identified in 89 patients;all had baseline adenomas removed at the first examination(year 0) colonoscopy and returned for the second(year 1).ACF in the lower rectum were assessed at year 0 and study group were divided into two groups depend on ACF numbers,0-3 or over 3.All participants were examined in the number and maximum size of adenoma.There was no statistical difference in number and maximum size of ACF at year 0,however,maximum size of adenoma was larger in over 3 group than 0-3 group at year 1.CONCLUSION:The number of ACF may be a predictive factor of relatively large adenoma incidence in the pilot phase study.

INHIBITORY EFFECT OF FERMENTED MILK ON DMH-INDUCED MICRO-NUCLEI AND APOPTOSIS IN THE COLON CRYPT CELLS OF MICE

The effect of fermented milk on micronuclei andapoptosis induced by DimethyIhydraziine(DMH)in thecolon crypt cells of mouse was studied.Fermented milk,milk and tap water were fed to three groups of C57BL mice.The animals were given DMH i.p.at a dosage of 20mg/kg onthe 7th day.The animals were sacrificed 24 hours

EPITHELIAL CELL NECROSES IN MOUSE INTESTINAL CRYPTS AFTER CONTINUE IRRADIATION WITH βRAYS FROM TRIATED WATER

In this paper epithelial cell necroses(apoptosis)of mouse intestinal crypts induced by βRays fromtritiated water(HTO)was reported.The resultsshowed that the number of apoptotic cells perintestinal crypt 20 hrs after injection of

Crypt region localization of intestinal stem cells in adults

The intestinal epithelial lining plays a central role in the digestion and absorption of nutrients,but exists in a harsh luminal environment that necessitates continual renewal.This renewal process involves epithelial cell proliferation in the crypt base and later cell migration from the crypt base to the luminal surface.This process is dependent on multi-potent progenitor cells,or stem cells,located in each crypt.There are about 4 to 6 stem cells per crypt,and these stem cells are believed to generate distinct end-differentiated epithelial cell types,including absorptive cells,goblet cells,enteroendocrine cells and Paneth cells,while also maintaining their own progenitor cell state.Earlier studies suggested that intestinal stem cells were located either in the crypt base interspersed between the Paneth cells [i.e.crypt base columnar(CBC) cell model] or at an average position of 4 cells from the crypt base [i.e.label-retaining cells(LRC +4) model].Recent studies have employed biomarkers in the in vivo mammalian state to more precisely evaluate the location of these progenitor cells in the intestinal crypt.Most notable of these novel markers are Lgr5,a gene that encodes a G-protein-coupled receptor with expression restricted to CBC cells,and Bmi 1,which encodes a chromatin remodeling protein expressed by LRC.These studies raise the possibility that there may be separate stem cell lines or different states of stem cell activation involved in the renewal of normal mammalian intestinal tract.

亚硒酸二葡萄糖酯对产蛋后期蛋鸭肠道形态和微生物的影响

选用240只50周龄健康的临武鸭蛋鸭,随机分成5组:对照组(第1组)在基础饲粮中添加0.2 mg/kg(以硒计)的亚硒酸钠,第2、3、4、5组分别在基础饲粮中添加0.1、0.2、0.3、0.4mg/kg(以硒计)的亚硒酸二葡萄糖酯。每组6个重复,每重复8只鸭。预试期7d,正试期63d。试验结束后测定供试鸭的十二指肠、空肠和回肠形态指标及回肠和盲肠的微生物多样性。结果表明:与对照组相比,饲粮添加亚硒酸二葡萄糖酯对产蛋后期蛋鸭的十二指肠、空肠和回肠绒毛高度、隐窝深度、肠壁厚度、绒毛高度与隐窝深度的比值均无显著影响;添加亚硒酸二葡萄糖酯组降低了回肠中变形菌门和埃希氏菌属–志贺氏杆菌属及盲肠中变形菌门和厌氧螺菌属的相对丰度,提高了回肠中肠杆菌属及盲肠中拟杆菌门和普雷沃氏菌属、肠杆菌属、理研菌科RC9菌属的相对丰度;第2组回肠中属、种水平的OTU数显著高于对照组的,肠道菌群α多样性最高,回肠中厚壁菌门相对丰度最高且埃希氏菌属–志贺氏杆菌属相对丰度最低,盲肠中拟杆菌门相对丰度最高。综上可知,饲粮添加亚硒酸二葡萄糖酯降低了回肠中有害微生物的相对丰度,有利于肠道健康,饲粮中亚硒酸二葡萄糖酯的适宜添加量为0.1mg/kg(以硒计)。

明代蜀藩王陵玄宫仿木构形制与营造技术分析

明代蜀藩王陵是现存明代皇家陵墓玄宫中仿木构做法最系统、仿木构信息最丰富的墓葬,也是巴蜀地区仿木构墓葬发展最后的高潮。通过分析巴蜀地区明代蜀藩王陵玄宫院落形制与地上宫室制度的相关性,辨析仿木构单体建筑对地上建筑木构信息的取舍、木构特征还原度及仿木材料与构造方式等问题,展现了皇家陵墓玄宫营造中仿木设计思路及仿木材料与技术的独特性。研究对缺乏地面实例的巴蜀明代皇家木构建筑研究具有一定的参考价值。