Making the link between ADF and 4D STEM:Resolution,transfer and coherence

Steve Pennycook is a pioneer in the application of high-resolution scanning transmission electron microscopy(STEM)and in particular the use of annular dark-field(ADF)imaging.Here we show how a general framework for 4D STEM allows clear links to be made between ADF imaging and the emerging methods for reconstructing images from 4D STEM data sets.We show that both ADF imaging and ptychographical reconstruction can be thought of in terms of integrating over the overlap regions of diffracted discs in the detector plane.This approach allows the similarities in parts of their transfer functions to be understood,though we note that the transfer functions for ptychographic imaging cannot be used as a measure of information transfer.We also show that conditions of partial spatial and temporal coherence affect ADF imaging and ptychography similarly,showing that achromatic interference can always contribute to the image in both cases,leading to a robustness to partial temporal coherence that has enabled high-resolution imaging.

The Protective Effects of Flavonoids from Scutellaria Baicalensis Georgi Stems and Leaves on Oligodendrocyte Damage Induced by Aβ1-42

Aim: This study aimed to investigate the protective effects of flavonoids from the stem and leaves of Scutellaria baicalensis Georgi (SSFs) against Aβ1-42-induced oligodendrocytes (OL) damage. Methods: Immunofluorescence was used for the detection of myelin-associated glycoprotein (MAG), a characteristic protein of rat oligodendrocytes (OLN-93 cells). To evaluate the potential protective effects of SSFs on OLN-93 cells injured by Aβ1-42, an injury model was established by subjecting OLN-93 cells to Aβ1-42 exposed. Cell morphology was examined using an inverted microscope, while cell viability was assessed using the colorimetric method of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Additionally, lactate dehydrogenase (LDH) was measured using the pyruvic acid reduction assay. The Ginkgo biloba leaf extract (GBE) injection was used as a positive control. Results: A total of >95% of the MAG immunofluorescence-positive cells were identified as oligodendrocytes. Gradually increasing concentrations of SSFs impaired the cells, and the maximum nondetrimental dose for OLN-93 cells was 75 mg/L. This study assessed the effects of SSFs on OLN-93 cells damaged by Aβ1-42. The results indicated that SSFs significantly improved OLN-93 cell morphological abnormal changes, increased the OLN-93 cell survival rate, and reduced LDH release. Conclusion: SSFs can alleviate Aβ1-42-induced damage of OL.

STUDY ON DYNAMICS OF STEM FORM OF KOREAN PINE TREES IN NATURAL FOREST STAND

A new method was proposed to study the dynamics of stem form of matural Korean pine (Pinus koraiensis) trec. In natural Korean Pine forest, the occurring time of maximum height and diameter is very difference. This paper connected stem form to stage of tree growth to analysis the form dynamic of Korean pine. The monomolecular equation was chosen as the stem model. The result shows that the maximum growth year of natural Korean pine is earlier than diameter.

基于肠道菌群平衡分析微生态制剂联合浙贝黄芩汤对急性淋巴细胞白血病大剂量化疗后患者的临床影响

目的探讨微生态制剂联合浙贝黄芩汤对急性淋巴细胞白血病(ALL)大剂量化疗后患者粒细胞集落刺激因子受体(G-CSFR)、粒单系集落形成单位(CFU-GM)、肠道菌群及红系爆式集落形成单位(BFU-E)的影响。方法选取延安大学附属医院2019年6月至2022年12月收治的ALL患者130例作为研究对象,根据治疗方法将患者分为A组、B组、C组,3组患者均接受大剂量化疗,化疗结束48 h后A组患者实施常规治疗,B组患者单纯浙贝黄芩汤治疗,C组给予微生态制剂联合浙贝黄芩汤治疗,治疗12 d后,对3组患者G-CSFR、CFU-GM、BFU-E表达情况及血细胞数量进行检测。结果治疗后,C组血红蛋白、白细胞、血小板[(79±6)g/L、(3.8±0.4)×10^(9)/L、(66.4±3.6)×10^(9)/L]与A组[(59±7)g/L、(3.2±0.4)×10^(9)/L、(52.6±2.8)×10^(9)/L]、B组[(61±7)g/L、(3.1±0.3)×10^(9)/L、(52.8±2.6)×10^(9)/L]对比,差异有统计学意义(P<0.05)。C组G-CSFR(5.35±0.16)pg/ml和白细胞介素-11受体(IL-11R)(6.38±0.54)μg/kg水平均高于A组[(2.23±0.13)pg/ml和(1.49±0.24)μg/kg]和B组[(2.31±0.16)pg/ml和(2.31±0.49)μg/kg]差异有统计学意义(P<0.05)。治疗后,C组患者7 d CFU-GM(18.5±6.0)个和14 d BFU-E(83.5±7.5)个高于A组[7 d CFU-GM(9.5±2.0)个和14 d BFU-E(59.5±6.5)个]和B组[7 d CFU-GM(12.0±6.5)个和14 d BFU-E(63.5±5.0)个],差异有统计学意义(P<0.05)。7 d后,C组双歧杆菌(12.56±3.25)lgCFU/g、乳酸杆菌(13.56±2.58)lgCFU/g、肠杆菌(5.12±1.45)lgCFU/g、肠球菌(5.14±0.58)lgCFU/g高于A组[(9.26±1.03)lg CFU/g、(8.65±0.84)lg CFU/g、(8.08±0.64)lgCFU/g、(8.15±0.46)lgCFU/g]和B组[(11.35±1.36)lg CFU/g、(12.43±1.14)lgCFU/g、(6.49±0.55)lgCFU/g、(6.66±0.43)lgCFU/g],差异有统计学意义(P<0.05)。结论微生态制剂联合浙贝黄芩汤治疗可以有效提高ALL大剂量化疗后患者的G-CSFR、CFU-GM、BFU-E水平,可能更好地改善化疗引起的患者骨髓抑制情况,改善肠道菌群,具有临床研究价值。

修枝强度对水曲柳人工林生长和干形的影响

为了探究水曲柳(Fraxinus mandshurica)幼林的适宜修枝强度,促进水曲柳生长和形成良好的干形,以15年生和20年生水曲柳人工林为研究对象,设置不修枝(对照)和对树高30%、40%、50%、60%进行修枝的5种处理,在修枝5、6 a后进行水曲柳生长和干形指标的测定。结果表明:除50%、60%修枝强度外,修枝后两林分水曲柳林木的各生长指标均高于对照,其中40%修枝强度时,两林分水曲柳林木的胸径、单株材积、林分蓄积量均最大,两林分水曲柳林木的胸径分别比对照提高了4.94%、5.56%,两林分水曲柳林木的单株材积分别比对照提高了4.38%、16.06%,两林分水曲柳林木的林分蓄积量分别比对照提高了13.59%、17.60%。修枝后两林分水曲柳林木树干的通直度、圆满度均高于对照,其中两林分水曲柳林木的树干通直度在60%修枝强度时最高,而树干圆满度均在40%修枝强度时最高,而两林分水曲柳林木的高径比在40%修枝强度时最低。结果表明,修枝后水曲柳林木生长和干形的改善主要源于水曲柳林木之间竞争的降低、光合效率的改善以及光合产物分配的变化。40%修枝强度是水曲柳林木生长和干形表现最优的修枝处理。

小型LOFT住宅空间多变性设计研究

LOFT住宅因其具有灵活的空间划分,充足的采光面积,个性自由的装修风格,功能界限的模糊性等特色被越来越多的年轻人所喜爱。小型LOFT住宅空间设计不仅要满足功能上的需求,更要注重的是对空间流线的巧妙划分,空间界面的创新处理,空间时间性的巧妙设计。即在满足功能的基础上,又能使LOFT空间不乏美观度,时尚感和趣味性。小型LOFT空间因其面积较小,要求每一寸空间都合理运用,多功能家具是不可或缺的一部分,同时我们需要注重空间中硬装与软装,实用性与美观性的完美结合。

烟秆生物炭及其改性对铅锌矿区污染土壤修复研究

生物炭(BC)在修复重金属污染土壤时,其修复效果与制备条件及原材料密切相关。以不同碳化温度(300、500和700℃)的烟秆生物炭BC及其纳米羟基磷灰石(nHAP)改性生物炭(HBC)为研究对象,采用微宇宙培养实验探究不同时段(7、14和30 d)烟秆BC及HBC对矿区Pb、Zn污染土壤的钝化修复效果。结果表明:不同温度的BC和HBC均能增加土壤pH值(7.81~8.56),并分别使土壤Pb毒性浸出浓度显著降低了30.02%~34.75%和28.23%~34.02%,使有效态Pb降低了37.95%~51.71%和22.56%~26.52%,有效态Zn降低了31.90%~55.52%和19.31%~41.70%;Pb、Zn生物有效性在培养7 d时降低最明显,不同BC使土壤Pb、Zn酸溶态降低了8%~11%和6%~14%,同时增加了可还原态、可氧化态和残渣态;而HBC则促使Pb、Zn酸溶态和可还原态向可氧化态和残渣态转化。BC对土壤Pb、Zn修复效果与HBC相当,因此,烟秆BC和HBC在钝化矿区Pb、Zn污染土壤方面具有显著效果,可为矿区土壤污染修复提供科学依据。

城市阁楼文化——浅谈LOFTS改造与城市居住的更新

本文对城市阁楼的定义及存在形式进行归纳,描述了世界阁楼式住宅的发展过程。对中国的城市阁楼文化的代表“北京大山子798艺术工厂”和“八号桥”时尚生活中心两个案例进行分析,以及“阁楼的遗风”在城市住宅设计中的反映,希望通过这样的分析与归纳对我们的建筑实践有一定的参考价值。

如何通过评价促进教师反思——美国大学STEM课堂评价工具REFLECT研究

REFLECT是美国最新研发的基于课堂观察的形成性教师教学评价工具,旨在培养反思型STEM教师。该工具包括观察前会议、选定观察主题、教师自我评估、同行课堂观察、学生即时反馈、观察者总结学生反馈、观察后会议等七个要素。它主要呈现出三个特点:突出形成性评价;保证评价的客观公正性;注重评价中的对话交流。该工具为如何通过评价促进教师反思提供了三点启示:实现评价主体多元化,为教师反思提供外部支持;充分发挥教师主体性,激发教师反思的内在动机;实施发展性教师评价,引领教师走向反思自觉。

Stem taper equations for diameter and volume predictions of Abies cilicica Carr.in the Taurus Mountains,Turkey

Taper equations are an important tool in estimating stem volumes at a multi-product level for sustainable forest management.Nine taper equations are tested from three categories to estimate diameter at specified point on the stem,height at specified diameter,volumes of any desired portion of the stem,and whole tree volume of Taurus fir in Taurus Mountains of Turkey.To account for autocorrelation and multicollinearity present among multiple stem data observations collected from the same tree.proper statistical approaches were used in model fitting.Comparisons are made to determine which equation provides the best overall fit to all data based on four goodness-of-fit statistics,Coefficient of determination(R2);Root mean square error(RMSE),Akaike’s Information Criterion(AIC),and Bayesian information criterion(BIC).Results indicated that all taper equations tested could be used to accurately estimate section diameter at given height and stem volume.Clark et al.’s taper equation provided better results than the others for Taurus fir when an additional stem diameter observation at 5.30 m was available.Segmented and variable-form taper models consistently provided better results than the simple taper models except for Max and Burkhart’s model.Fang et al.’s and Kozak’s taper models showed equally good performance to describe stem taper and to predict tree stem volume.Therefore,these taper equations are able to be used to estimate diameter and volume for Taurus fir trees,if an upper stem diameter measurement was not available.

Mesenchymal stem cells and the neuronal microenvironment in the area of spinal cord injury

Cell-based technologies are used as a therapeutic strategy in spinal cord injury(SCI). Mesenchymal stem cells(MSCs), which secrete various neurotrophic factors and cytokines, have immunomodulatory, anti-apoptotic and anti-inflammatory effects, modulate reactivity/phenotype of astrocytes and the microglia, thereby promoting neuroregeneration seem to be the most promising. The therapeutic effect of MSCs is due to a paracrine mechanism of their action, therefore the survival of MSCs and their secretory phenotype is of particular importance. Nevertheless, these data are not always reported in efficacy studies of MSC therapy in SCI. Here, we provide a review with summaries of preclinical trials data evaluating the efficacy of MSCs in animal models of SCI. Based on the data collected, we have tried(1) to establish the behavior of MSCs after transplantation in SCI with an evaluation of cell survival, migration potential, distribution in the area of injured and intact tissue and possible differentiation;(2) to determine the effects MSCs on neuronal microenvironment and correlate them with the efficacy of functional recovery in SCI;(3) to ascertain the conditions under which MSCs demonstrate their best survival and greatest efficacy.

Stimulation of Multiple Leader Formation in Some Genotypes of <i>Acacia mangium</i>and <i>Acacia auriculiformis</i>with 6-Benzylaminopurine (BAP)

Acacia mangium Willd. and Acacia auriculiformis A. Cunn. ex. Benth. are two of the fast-growing tropical acacias which have received priority for genetic assessment and improvement. They were therefore proposed for timber production in a short rotation in Malaysia but were impeded by the multiple leaders (ML) formation which limited their value as sawn timber. This work attempts to investigate the causes of ML formation in four genotypes of A. mangium and A. auriculiformis as related to apical dominance, nutrition and plant growth hormones and their correlations. The effects of 6-benzylaminopurine and decapitation on ML formation of these genotypes were also investigated. 6-benzylaminopurine (BAP) as a foliar spray and also decapitation did not stimulate ML formation. However, they significantly increased the number of branches and reduced all other growth traits including height. However, basal diameter was not affected by decapitation. The effects of BAP increased consistently with increasing level of application. BAP at 1500 mg&#183L&#451 resulted in mortality of A. mangium provenances while A. auriculiformis provenances survived and grew normally. Some of the BAP treated plants of both species developed juvenile pinnate leaves. Decapitation of the apical bud resulted in the activation of the lateral bud immediately below the point of decapitation.

Neuronal-like cell differentiation of non-adherent bone marrow cell-derived mesenchymal stem cells

Non-adherent bone marrow cell-derived mesenchymal stem cells from C57BL/6J mice were sepa- rated and cultured using the ＂pour-off＂ method. Non-adherent bone marrow cell-derived mesen- chymal stem ceils developed colony-forming unit-fibroblasts, and could be expanded by supple- mentation with epidermal growth factor. Immunocytochemistry showed that the non-adherent bone marrow cell-derived mesenchymal stem cells exposed to basic fibroblast growth factor/epidermal growth factor/nerve growth factor expressed the neuron specific markers, neurofilament-200 and NeuN, in vitro. Non-adherent bone marrow cell-derived mesenchymal stem cells from 13-galactosidase transgenic mice were also transplanted into focal ischemic brain （right corpus striatum） of C57BL/6J mice. At 8 weeks, cells positive for LacZ and 13-galactosidase staining were observed in the ischemic tissues, and cells co-labeled with both 13-galactosidase and NeuN were seen by double immunohistochemical staining. These findings suggest that the non-adherent bone marrow cell-derived mesenchymal stem cells could differentiate into neuronal-like cells in vitro and in vivo.

形成性评价在生理学基于STEM教育的混合式教学中的应用研究

目的研究形成性评价在生理学基于STEM教育的混合式教学中的应用效果。方法研究对象为山西卫生健康职业学院2020级药学专业103名学生,随机分为两组,实验组采用基于STEM教育的混合式教学,进行形成性评价;对照组采用传统教学,进行终结性评价。教学结束后,对比两组学生的综合素质、学业评价及学习满意度。结果实验组的综合素质、学业评价及学习满意度均显著优于对照组,组间差异有统计学意义(P<0.05)。结论在生理学教学过程中,形成性评价应用于基于STEM教育的混合式教学,有利于提高学生综合素质及教学效果。

泡桐无性系早期生长与干形综合选择

为筛选出速生和接干能力好的无性系,以江苏省宿迁市的13个泡桐无性系测定林为研究对象,利用混合线形模型对泡桐20个月树高(H_(20)),30个月树高(H_(30))、胸径(D_(30))、材积(V_(30))和30个月时接干能力指数(J_(30))性状进行遗传参数估算,同时,利用基因型综合指数选择法对30月龄泡桐无性系进行早期选择。试验结果表明,泡桐无性系早期生长快,H_(20)、H_(30)、D_(30)、V_(30)和J_(30)平均值分别为4.56 m、6.73 m、10.20 cm、0.0314 m^(3)和0.48;泡桐H_(20)、H_(30)、D_(30)、V_(30)和J_(30)在无性系间达极显著水平,其无性系重复力为0.69~0.99,单株重复力为0.15~0.85,说明遗传和环境因子均为影响泡桐生长的重要因素。生长性状间表型和遗传相关达到显著水平,接干能力指数与D_(30)和V_(30)间表型相关不显著,而与其他性状间的表型和遗传相关系数均达到了显著水平。以泡桐30个月时生长和接干能力指标进行早期选择,综合评选4个优良无性系49、01-23、01-22和4B,无性系入选率30.8%,其生长指标和接干能力指标均高于对照无性系,具有较高的遗传稳定性。

不同强度修枝对杉木木材密度、硬度及无节材比例的影响

为揭示修枝对杉木木材密度、硬度及无节材比例的影响规律,采用随机区组设计,在4年生杉木林中开展4种不同修枝强度(分别修除树干直径6、8、10、12 cm位置以下的枝条)处理试验。在修枝后20 a,按照平均标准木法选择不同修枝强度和对照处理标准木进行不同指标测定,研究修枝强度对杉木木材密度、硬度、干形、无节材比例等指标的长期影响。结果表明:修枝强度对杉木木材尖削度有显著影响,未修枝杉木木材尖削度为1.05%,修枝杉木尖削度均小于0.92%,修枝后杉木干形更趋于通直,树干形率增大。不同修枝强度处理杉木木材指标存在差异,修枝降低了杉木木材密度、硬度,但显著提高杉木无节材的比例,不同修枝处理无节材比例比未修枝提高5%~15%。10 cm修枝强度能明显增加无节材比例,但对杉木生长的影响不明显,是值得杉木无节材培育中推广的修枝强度。

施加不同形态氮肥对芦苇生长和茎秆理化特性的影响

在位于四川省绵阳市涪城区青义镇的西南科技大学芦苇温室大棚,于2022年5月20日,将购自河北雄安聚鹏生态科技有限公司的白洋淀白花芦苇、白洋淀黄花芦苇、宿州芦苇的地下根系扦插盆内,在大棚内育苗15 d, 6月5日选取长势良好,大小一致的幼苗盆栽;选用不同形态氮素(酰胺态氮(CO(NH_(2))_(2))、铵态氮(NH4Cl)、硝态氮(KNO_(3)))设计单施、混施8种施肥方案(其中以不施氮肥为对照)对芦苇(Phragmites australis)扦插苗进行施肥试验,每个处理3次重复,每个重复4株,共96株;10月6—7日,测定成熟期芦苇的株高、第三节节间长、植株干质量,各处理分别随机选取3株,以全株收获取样,测定生物量、纤维形态、纤维素、木质素;分别取未施肥前盆中、施肥后成熟期盆中3~7 cm土层的土壤,测定土壤肥力(包括全氮磷钾、速效氮磷钾、土壤pH等);结合测定指标,应用方差分析法(ANOVA)、最小显著性差异法(LSD),分析施加不同形态氮肥对芦苇生长和茎秆理化特性的影响。结果表明:混施酰胺态氮和铵态氮,对白洋淀黄花芦苇的表型和干质量有促进作用,对改善白洋淀白花芦苇、白洋淀黄花芦苇的纤维形态效果最佳;混施酰胺态氮和铵态氮,白洋淀黄花芦苇、白洋淀白花芦苇的纤维素质量分数显著提高,白洋淀黄花芦苇的木质素质量分数最低;单施酰胺态氮,对宿州芦苇纤维素质量分数促进效果最显著。综合试验结果,混施酰胺态氮和铵态氮,对促进植株生长、改善纤维形态、提高纤维利用率的效果最佳;综合各项指标,白洋淀黄花芦苇更具有优良纤维用原料的潜力。

尼勒克喀什河国家湿地公园植物组成结构及其与环境的关系

于2019和2020年对尼勒克喀什河国家湿地公园植物组成结构及其与环境的关系进行了调查,结果表明:共记录到高等维管植物180种,隶属53科140属。进一步分析不同生活型植物的生长型和水分生态类型组成发现,地面芽植物普遍具有分枝型、直根型和中生的生长和生态特征,是阳性草地的主要类群;地下芽植物则普遍具有直立型、根茎型和湿生的生长和生态特征,是湿草甸和沼泽的主要类群;一年生植物具有分枝型、刷状根和中、旱生的生长和生态特征,为沙地、干旱坡地等生境的主要类群;地上芽植物则以分枝型、直根型和旱生性为表征,是极旱生境的主要类群。尼勒克喀什河国家湿地公园植物群落组成具有典型的温带植被特征,但同时也叠加了土壤水分条件的作用,形成以温带地面芽植物为主、湿生成分和一年生荒漠成分并重的格局。未来应加强湿地生境管理,提升湿地属性,增强湿地功能。

干形数据采样方法对树干削度方程构建的影响

【目的】基于落叶松15个点的直径-树高干形数据,比较树干不同采样方法对曾伟生(1997)、Bi(2000)和Max&Burkhart(1976)削度模型预测精度的影响。【方法】以大兴安岭343株落叶松干形数据为研究对象,设计了30种数据采样方法,使用留一交叉验证法对基于原始数据和不同采样数据的模型进行检验,选用确定系数(R2)、平均绝对误差(MAB)、均方根误差(RMSE)和相对误差(MPB)作为检验的评价指标,并求出以上4个指标的平均相对排序值。使用Tukey多重比较法对基于不同采样数据的模型进行成对比较,分析当拟合数据改变的情况下各削度模型在预测落叶松直径时是否有显著差异。最后为了直观地表示不同采样数据对削度模型的影响,从落叶松数据中分别随机抽取一株大树和一株小树进行树干模拟。【结果】1)相对于使用原始数据时的模型,基于一部分采样方法的模型检验精度有略微提高,其中使用第27种方法时,曾伟生模型的精度最高;使用第26种方法时,Bi的模型精度最高;使用第9种方法时,Max&Burkhart的模型精度最高;2)Tukey多重比较结果表明,基于原始数据和基于3种最优采样方法的削度模型在预测落叶松直径时,模型两两之间均没有显著差异;3)通过对落叶松小树和大树的树干进行模拟发现,使用原始数据时的削度模型,与使用最优采样数据时的削度模型,对树干的模拟效果几乎相同。【结论】针对不同的削度模型,其最适用的采样方法也不同。当使用曾伟生的模型对大兴安岭落叶松树干削度预测时可以选择方法 27中7个点的直径-树高数据进行拟合,即将树干分成7个区分段进行干形测量;当使用Bi的模型时可以选择方法 26中的7个区分段进行干形测量;当使用Max&Burkhart的模型时可以选择方法 9中的10个区分段进行干形测量;当同时考虑这3个模型时,可以选择方法 20中的8个区分段进行干形测量,此时3个模型对落叶松树干不同位置处直径的预测精度均会略有提高。

珍贵树种红椿干形培育研究进展

红椿是我国Ⅱ级重点保护植物,也是重要的珍贵树种。红椿材质优良,具有较高的木材利用率,是少有的可以通株加工利用的乔木;近年来市场对木材的需求量不断增加,红椿作为重要经济树种,对木材产业发展具有重要的作用。本文综述了红椿干形和生长的相关研究进展,围绕形数及形率、干形遗传改良研究、立地条件及气候因子对干形的影响进行探讨,以期为红椿高质、高效和可持续发展提供理论指导。