气候适应视角下南疆荒漠绿洲城镇水城融合模式研究

受南疆荒漠绿洲地区气候约束及人为影响,城镇地表水时空分配不均现象严重,传统水资源利用模式难以满足现代绿洲发展需求。针对城镇转型中水源紧缺、气候约束下的治水考验、水城分离下的服务缺失等问题,通过循环调蓄一体化的水网格局重塑、防洪景观与生态修复的在地性设计、绿洲特色滨水功能服务体系搭建,激发水资源综合服务潜力,促进现代荒漠绿洲水城融合。

服务效能提升视角下近郊陂塘保护性利用策略研究--以重庆黛湖沿线陂塘水系为例

陂塘水系分布广泛、数量众多,具有重要的生态价值。在快速城市化背景下,由于对其服务价值认识不足,近郊大量陂塘水体遭到破坏,严重危及水文生态系统安全。为破解难题,寻求积极主动的生态修复模式,以重庆黛湖沿线陂塘水系为研究对象,分析其削减原因,从生态、游赏、经济等角度进行价值再判断,据此提出基于服务效能提升的分工合作、生态修复及功能修补策略。

Comment on:Clinical Characteristics,Diagnosis,and Treatments for COVID-19

The clinical characteristics of COVID-19 patients have been well summarized by Xie et al.However,we should pay attention to another special manifestation of COVID-19,COVID-19-related immune reconstitution inflammatory syndrome(IRIS).SARS-CoV-2,an infectious agent,can alscoause IRIS,similar to Mycobacterium tuberculosis.In the era of the COVID-19 pandemic,increasing cases of COVID-19-related IRIS have been reported.However,the definition and detailed criteria of COVID-19-related IRIS have not been thoroughly clarified.Clinicians should pay attention to 3 essential components in a classical model of IRIS,including a primary disease that causes immunosuppression,a trigger that induces immune reconstitution.

病理性近视并发黄斑裂孔玻璃体切除联合内界膜剥除术后疗效分析

目的:探讨玻璃体切除联合内界膜剥除术治疗病理性近视黄斑裂孔的临床效果。方法:回顾性研究。选取2017-01/2019-01于我院确诊的高度近视黄斑裂孔患者18例19眼,将其分为病理性近视组(9例10眼)和非病理性近视组(9例9眼),均接受玻璃体切除联合内界膜剥除术。术后随访3~23mo,观察两组患者末次随访时最佳矫正视力(BCVA)、视物变形症状及黄斑裂孔闭合情况。结果:末次随访时,病理性近视组术后BCVA提高6眼,不变2眼,下降2眼,黄斑裂孔完全闭合7眼(70%),裸露型闭合2眼(20%),未闭合1眼(10%);非病理性近视组术后BCVA提高6眼,不变2眼,下降1眼,黄斑裂孔完全闭合8眼(88%),裸露型闭合1眼(11%)。术前两组患者眼轴长度有明显差异,眼轴长度与末次随访时黄斑裂孔闭合率呈负相关(rs=-0.477,P=0.039)。结论:玻璃体切除联合内界膜剥除术治疗高度近视黄斑裂孔可有效改善最佳矫正视力,但病理性近视患者裂孔闭合率低于非病理性近视患者。

学龄前儿童弱视的早期筛查

弱视是一种由视觉敏感期异常视觉经验引起的以神经系统发育异常为主、无眼部器质性病变的疾病。视力检查是儿童弱视筛查与诊断中的重要组成部分,但对于不能言语表达的低龄儿童,视力检查受到限制。而屈光不正和屈光参差是引起弱视的最常见危险因素,近年来,对弱视的早期筛查不断延伸至对弱视相关危险因素的早期筛查,针对屈光状态的筛查方法与技术也在不断更新发展。本文试对视力检查方法和屈光性质筛查方法进行综述。

阿维菌素的中国“智”造

阿维菌素(avermectins)是由微生物发酵生产的高效低毒生物杀虫剂,在粮食安全、农产品安全、畜牧业和医药健康等领域具有重大意义。其衍生物伊维菌素(ivermectins)可有效治疗河盲症,帮助超过2亿非洲人幸免于失明。我国的阿维菌素产业利用遗传学改造手段深入挖掘微生物的潜能,大幅度提高了底物利用率、目标产物得率和反应器产率,打破了美国默克公司的产品垄断,从无到有,从弱到强,直至独占全球市场。阿维菌素的生物"智"造不但成为实验室技术向产业成功转化的典范,为其他微生物天然产物药物的研发提供了可借鉴的策略和方法,而且得到广泛的国际认可。本文介绍了阿维菌素的发现、基础及应用研究的发展历程,尤其是中国"智"造的历史沿革,旨在为我国微生物药物的产业化发展提供参考和借鉴。

西部中小旅游城市照明规划中的景观经济策略研究

针对当前夜景照明规划忽视城市夜景建设所蕴含的巨大经济潜力,避免步入为景观而景观的设计误区。本文提出将景观经济策略引入西部中小旅游城市的景观照明规划过程中,以夜景照明建设为契机,从市场化运作的景观照明设施布局、“点—轴”发展理论的重点打造、产业链联动发展的夜间旅游开发三个方面,实现城市环境品质优化、经济良性发展的双赢效应。并以柳州市三江侗族自治县为例进行具体剖析。

近视性视网膜劈裂研究进展

近视性视网膜劈裂(MRS)是病理性近视的一大并发症。目前MRS的发病机制并不十分明确,可能是多种因素共同参与的结果,玻璃体后皮质及内界膜对视网膜的牵引被认为会导致视网膜劈裂的形成。另外,眼轴长度的延长和视网膜小动脉牵拉也与MRS的发病机制有关。MRS的诊断主要依赖于光学相干断层扫描、眼部B超及超广角眼底自发荧光检查结果。在MRS自然病程中,通常视力和视网膜厚度长期保持稳定,而引起黄斑部病变会导致视力逐渐下降,如黄斑裂孔、中央凹视网膜脱离、黄斑前膜。MRS的治疗方法主要有玻璃体切除术、黄斑扣带术等。本文主要对病理性近视视网膜劈裂的发病机制、检查方法、自然病程转归及治疗进展做一综述。

三维空间椭圆信道模型及其均匀矩形阵列研究

为研究无线多输入多输出(MIMO)系统信道特性,在考虑无线信道模型的信号传播复杂性与空间性的基础上,提出一种适用于户外环境的三维空间椭圆信道模型,并在其收发端设置均匀矩形阵列(URA)。利用该模型分析MIMO天线系统性能,推导出到达角、到达时间的概率密度函数表达式,并研究影响URA空间相关性与信道容量的因素。理论分析与实验结果表明,在基于URA的三维空间椭圆信道模型中,方位扩展角(AS)是影响URA空间相关性的主要因素,而收发端天线间距也会对URA信道容量产生一定影响,该结论对于无线信道模型的应用范围扩展及天线阵列灵敏度分析具有重要的参考和借鉴价值。

基于生态修复理念的山地城市公园规划设计研究--以重庆市鹿山公园为例

随着经济建设的快速发展,人们对山地资源的不合理开发利用导致山地生态环境问题突出。该文以重庆市鹿山公园为研究范例,以生态修复理念为核心,将其贯彻于生态已受损的山地公园规划设计中,以期达到修复山地生态系统,美化山地环境的目的,同时为其他城市建设、改善山地公园生态受损环境提供一定经验和借鉴意义。

Anisotropy in mechanical properties and corrosion resistance of 316L stainless steel fabricated by selective laser melting

The corrosion behavior and mechanical properties of 316 L stainless steel(SS) fabricated via selective laser melting(SLM) were clarified by potentiodynamic polarization measurements, immersion tests, and tensile experiments. The microstructural anisotropy of SLMed 316 L SS was also investigated by electron back-scattered diffraction and transmission electron microscopy. The grain sizes of the SLMed 316 L SS in the XOZ plane were smaller than those of the SLMed 316 L SS in the XOY plane, and a greater number of low-angle boundaries were present in the XOY plane, resulting in lower elongation for the XOY plane than for the XOZ plane. The SLMed 316 L was expected to exhibit higher strength but lower ductility than the wrought 316 L, which was attributed to the high density of dislocations. The pitting potentials of the SLMed 316 L samples were universally higher than those of the wrought sample in chloride solutions because of the annihilation of MnS or(Ca,Al)-oxides during the rapid solidification. However, the molten pool boundaries preferentially dissolved in aggressive solutions and the damage of the SLMed 316 L in FeCl3 solution was more serious after long-term service, indicating poor durability.

Effects of chitosan inhibitor on the electrochemical corrosion behavior of 2205 duplex stainless steel

The effects of chitosan inhibitor on the corrosion behavior of 2205 duplex stainless steel were studied by electrochemical measurements, immersion tests, and stereology microscopy. The influences of immersion time, temperature, and chitosan concentration on the corrosion inhibition performance of chitosan were investigated. The optimum parameters of water-soluble chitosan on the corrosion inhibition performance of 2205 duplex stainless steel were also determined. The water-soluble chitosan showed excellent corrosion inhibition performance on the 2205 duplex stainless steel. Polarization curves demonstrated that chitosan acted as a mixed-type inhibitor. When the stainless steel specimen was immersed in the 0.2 g/L chitosan solution for 4 h, a dense and uniform adsorption film covered the sample surface and the inhibition efficiency(IE) reached its maximum value. Moreover, temperature was found to strongly influence the corrosion inhibition of chitosan; the inhibition efficiency gradually decreased with increasing temperature. The 2205 duplex stainless steel specimen immersed in 0.4 g/L water-soluble chitosan at 30°C displayed the best corrosion inhibition among the investigated specimens. Moreover, chitosan decreased the corrosion rate of the 2205 duplex stainless steel in an FeCl_3 solution.

酯酶荧光探针的研究现状与进展

酯酶是一类丝氨酸蛋白酶,在生物体内被用于催化许多含有酯、酰胺、硫酯或乙酰基的化合物的水解。在生物体内,酯酶不仅起着重要的生理事件调节功能,参与各类药物的水解或激活,而且还参与许多病理事件(如肝癌),这可能与它独特的解毒功能有着密切的关系。因此,开发新的、有效的酯酶检测平台对生物和医学研究具有重要意义。与传统手段相比,荧光探针具有灵敏度高、选择性好、响应迅速、成本低、操作方便等诸多优势。因此用荧光探针检测酯酶是个很好的选择。本文主要综述了检测酯酶荧光探针的研究现状及最新进展。

Sonic Hedgehog signaling pathway in primary liver cancer cells

Objective:To investigate clinical significance of Sonic Hedgehog(SHH)signaling pathway molecular Shh,Smo and Gli2 in primary hepatocellular carcinoma(HCC)tissue.Methods:A total of 30 HCC tissue samples were collected.Protein expression of SHH signaling pathway molecules Shh,Smo and Gli2 in HCC tissues and para-carcinoma tissue were detected by using immimohistochemical method.Cirrhosis and normal liver tissue specimens were observed as control to analyze the expression of SHH signaling pathway molecular Shh,Smo and Glil mRMA in HCC tissues and corresponding para—carcinoma tissues and its relationship with the onset of HCC.Results:There was no expression of Shh,Smo and Gli2 protein in normal liver tissue,while their positive rates were 63.3%,76.79%and 66.7%in HCC tissues,respectively,with a significantly higher expression level than that in the para-carcinoma tissue(P<0.05).The protein expressions in HepG2 cells were slightly lower than that in Huh7 cells,with no statistical difference(P>0.05);Shh and Smo protein was detected in part of cirrhosis with positive expression,but Gli2 protein was not observable in cirrhosis tissues.Conclusions:In HCC tissues,the high expression level of SHH signaling pathway molecules signal peptide(Shh),membrane protein receiptor(Smo)and nuclear transcription molecular(Gli2)can be indicators of the onset of liver cancer.

Combination of ranibizumab with photodynamic therapy vs ranibizumab monotherapy in the treatment of age-related macular degeneration: a systematic review and meta-analysis of randomized controlled trials

AIM:To compare the efficacy and safety of combination of ranibizumab with photodynamic therapy(PDT)vs ranibizumab monotherapy in the treatment of age-related macular degeneration(AMD).METHODS:The Cochrane Central Register of Controlled Trials(CENTRAL)in the Cochrane Library,Pubmed,and Embase were searched.There were no language or data restrictions in the search for trials.Only randomized controlled trials(RCTs)were included.Methodological quality of the literatures was evaluated according to the Jadad Score.RevMan 5.2.6 software was used to do the meta-analysis.RESULTS:Seven studies were included in our systematic review,among which four of them were included in quantitative analysis.The result shows that the ranibizumab monotherapy group had a better mean best corrected visual acuity(BCVA)change vs baseline at month 12 compared with that of the combination treatment group,and the statistical difference was significant(WMD,-2.61;95%CI,-5.08 to-0.13;P=0.04).However,after the removal of one study,the difference between the two groups showed no significant difference(WMD,-2.29;95%CI,-4.81 to 0.23;P=0.07).Meanwhile,no significant central retinal thickness(CRT)reduction was found in the combination treatment group and the ranibizumab monotherapy group at 12 months follow-up.Nevertheless,the combination group tended to have a greater reduction in CRT(WMD,-4.13μm;95%CI,-25.88to 17.63,P=0.71).The proportion of patients gaining more than 3 lines at month 12 in the ranibizumab group was higher than in the combination group and there was a significant difference(RR,0.72;95%CI,0.54 to 0.95;P=0.02).Whereas there was no significant difference for the proportion of patients gaining more than 0 line at month12 between the two groups(RR,0.93;95%CI,0.76 to1.15;P=0.52).The general tendency shows a reduction in ranibizumab retreatment number in the combination treatment group compared with the ranibizumab monotherapy group.As major adverse events,the differences in the number of eye pain,endophthalmitis,hypertension and arterial thromboembolic events were not significant between the two groups,and the incidence of serious adverse events in the two groups was very low.CONCLUSION:For the maintenance of vision,the comparison of the combination of ranibizumab with PDT vs ranibizumab monotherapy shows no apparent difference.Compared with the combination of ranibizumab and PDT,patients treated with ranibizumab monothearpy may gain more visual acuity(VA)improvement.The combination treatment group had a tendency to reduce the number of ranibizumab retreatment.Both the two treatment strategies were well tolerated.

基于机器视觉的海上目标智能化预警观测过程模型与技术方法

海洋态势感知与目标观测技术正向着自动化、智能化发展。光电监控系统作为海洋目标活动态势感知中不可或缺的必要手段,在面向长期无人值守的持续海上预警观测应用场景中,其自主运行能力受到极大考验。本文基于多年研究以及相关项目实践,提出了基于机器视觉的海上目标智能化预警观测的一般过程模型与相关的技术实现方法,通过基于深度学习的目标识别模型和一体化的联动跟踪机制驱动光电传感器智能自主运行,在全自动托管的情况下实现目标发现、跟踪、识别、取证、再发现闭环持续工作,为海上目标活动视觉特征提取与信息服务提供有力支撑。

Change of retinal nerve fiber layer thickness in patients with nonarteritic inflammatory anterior ischemic optic neuropathy

In this study, 16 patients （19 eyes） with nonarteritic anterior ischemic optic neuropathy in the acute stage （within 4 weeks） and resolving stage （after 12 weeks） were diagnosed by a series of complete ophthalmic examinations, including fundus examination, optical coherence tomography and fluorescein fundus angiography, and visual field defects were measured with standard automated perimetry. The contralateral uninvolved eyes were used as controls. The retinal nerve fiber layer thickness was determined by optical coherence tomography which showed that the mean retinal nerve fiber layer thickness and the retinal nerve fiber layer thickness from temporal, superior, nasal and inferior quadrants were significantly higher for all measurements in the acute stage than the corresponding normal values. In comparison, the retinal nerve fiber layer thickness from each optic disc quadrant was found to be significantly lower when measured at the resolving stages, than in the control group. Statistical analysis on the correlation between optic disc nerve fiber layer thickness and visual defects demonstrated a positive correlation in the acute stage and a negative correlation in the resolving stage. Our experimental findings indicate that optical coherence tomography is a useful diagnostic method for nonarteritic anterior ischemic optic neuropathy and can be used to evaluate the effect of treatment.

Revisiting the role of delta-1-pyrroline-5-carboxylate synthetase in drought-tolerant crop breeding

The delta-1-pyrroline-5-carboxylate synthetase(P5CS)gene exercises a protective function in stressed plants.However,the relationship between proline accumulation caused by P5CS and abiotic stress tolerance in plants is not always clear,as P5CS overexpression has been reported to repress plant growth under normal conditions in several reports.We re-evaluated the role of P5CS in drought-tolerant rice breeding by expressing the AtP5CS1 and feedback-inhibition-removed AtP5CS1(AtP5CS1^(F128A))genes under the regulation of an ABA-inducible promoter to avoid the potential side effects of P5CS overexpression under normal conditions.ABA-inducible AtP5CS1 and AtP5CS1^(F128A) increased seedling growth in a nutrient solution(under osmotic stress)and grain yield in pot plants.However,the evidently deleterious effects of AtP5CS1 on grain quality,tiller number,and grain yield in the field indicated the unsuitability of P5CS for drought-tolerance breeding.

Short-term effects of intravitreal Conbercept injection combined with laser photocoagulation on macular edema secondary to ischemic retinal vein occlusion

AIM:To observe changes in the best-corrected visual acuity(BCVA),central macular thickness(CMT),and central choroidal thickness(CCT)of patients with macular edema(ME)secondary to ischemic retinal vein occlusion(i RVO)following intravitreal Conbercept injection.METHODS:This retrospective study included 33 eyes from 33 patients who received intravitreal injections of Conbercept for ME secondary to i RVO.Treatments were performed on a 3+pro re nata(3+PRN)basis.All of the patients were examined by fundus fluorescein angiography and spectral domain optical coherence tomography at the first visit.Laser photocoagulation was performed in the nonperfusion area of the retina of all eyes after the first injection.BCVA,CMT,and CCT were observed before and after 6 mo of treatment.The number of injections necessary to achieve improved vision was also noted.RESULTS:Following Conbercept treatment,the mean BCVA significantly improved from 0.81±0.39 at baseline to 0.41±0.25 and 0.43±0.29 log MAR in the third and sixth months,respectively(both P=0.000).The CMT of the patients at baseline was 556.75±98.57μm;304.78±68.53 and 306.85±76.77μm 3 and 6 mo after treatment,respectively(both P=0.000 vs baseline).The CCTs of the patients at baseline,3 and 6 mo after treatment were 304.63±57.83,271.31±45.53,and 272.29±39.93μm,respectively(P=0.026 and 0.035 vs baseline).No severe adverse event relevant to the therapy was noted,and the average number of injections delivered was 3.35.CONCLUSION:Intravitreal Conbercept injection combined with laser photocoagulation appears to be a safe and effective treatment for ME secondary to i RVO in the short-term.

Hub genes associated with immune cell infiltration in breast cancer, identified through bioinformatic analyses of multiple datasets

Objective:The aim of this study was to identify hub genes associated with immune cell infiltration in breast cancer through bioinformatic analyses of multiple datasets.Methods:Nonparametric(NOISeq)and robust rank aggregation-ranked parametric(EdgeR)methods were used to assess robust differentially expressed genes across multiple datasets.Protein-protein interaction network,GO,KEGG enrichment,and subnetwork analyses were performed to identify immune-associated hub genes in breast cancer.Immune cell infiltration was evaluated with the CIBERSORT,XCELL,and TIMER methods.The association between the hub gene-based risk signature and survival was determined through Kaplan–Meier survival analysis,multivariate Cox analysis,and a nomogram with external verification.Results:We identified 163 robust differentially expressed genes in breast cancer through applying both nonparametric and parametric methods to multiple GEO(n=2,212)and TCGA(n=1,045)datasets.Integrated bioinformatic analyses further identified 10 hub genes:CXCL10,CXCL9,CXCL11,SPP1,POSTN,MMP9,DPT,COL1A1,ADAMDEC1,and RGS1.The 10 hub-gene-based risk signature significantly correlated with the prognosis of patients with breast cancer.Moreover,these hub genes were strongly associated with the extent of infiltration of CD4+T cells,CD8+T cells,neutrophils,macrophages,and myeloid dendritic cells into breast tumors.Conclusions:Integrated analyses of multiple databases led to the discovery of 10 robust hub genes that together may serve as a risk factor characteristic of the immune microenvironment in breast cancer.