Tuning the surface electronic structure of noble metal aerogels to promote the electrocatalytic oxygen reduction

The sluggish kinetics of the oxygen reduction reaction(ORR)is the bottleneck for various electrochemical energy conversion devices.Regulating the electronic structure of electrocatalysts by ligands has received particular attention in deriving valid ORR electrocatalysts.Here,the surface electronic structure of Ptbased noble metal aerogels(NMAs)was modulated by various organic ligands,among which the electron-withdrawing ligand of 4-methylphenylene effectively boosted the ORR electrocatalysis.Theoretical calculations suggested the smaller energy barrier for the transformation of O^(*) to OH^(*) and downshift the d-band center of Pt due to the interaction between 4-methylphenylene and the surface metals,thus enhancing the ORR intrinsic activity.Both Pt3Ni and Pt Pd aerogels with 4-methylphenylene decoration performed significant enhancement in ORR activity and durability in different media.Remarkably,the 4-methylphenylene modified Pt Pd aerogel exhibited the higher halfwave potential of 0.952 V and the mass activity of 10.2 times of commercial Pt/C.This work explained the effect of electronic structure on ORR electrocatalytic properties and would promote functionalized NMAs as efficient ORR electrocatalysts.

Analyses on the misdiagnoses of 25 patients with unilateral optic nerve sheath meningioma

AIM：To investigate clinical features of optic nerve sheath meningioma（ONSM） that was misdiagnosed,and to find methods to reduce the misdiagnoses.METHODS：Retrospective series study.Twenty-five misdisgnosed patients with unilateral ONSM were collected from Jan.2008 to Jan.2015 and the clinical records reviewed.RESULTS：Patients were misdiagnosed with acute papillitis most frequently（P=17）,immediately followed by optic atrophy（P=8）,ischemic optic neuropathy（P=5）,acute retrobulbar optic neuritis（P=5）,optic disc vasculitis（P =3）.For each patient,the minimum frequency of misdiagnoses was once and the maximum was 4 times.As for the lasting time of being misdiagnosed,the shortest was 1.5mo and the longest was 45 mo.Twentyone cases（84%） were once treated with glucocorticoids,and its side effects was found in seventeen patients.Twenty patients（80%） complained with varying degree of vision loss.When a definite diagnosis was made,sixteen cases（64%） showed slight exophthalmos and eighteen cases（72%） had the tubular ONSM.CONCLUSION：ONSM without loss obvious exophthalmos is easily misdiagnosed in clinic,and for most of these ONSMs are tubular.

Differentiation of human embryonic stem cells derived mesenchymal stem cells into corneal epithelial cells after being seeded on decellularized SMILE-derived lenticules

AIM: To evaluate the feasibility of mesenchymal stem cells(MSCs) to differentiate into corneal epithelial cells after being seeded on the decellularized small incision lenticule extraction(SMILE)-derived lenticules. METHODS: The fresh lenticules procured from patients undergoing SMILE for the correction of myopia were decellularized. The MSCs were subsequently cultivated on those denuded lenticules. The MSCs without lenticules were used as a control. The proliferation activity of the MSCs after seeding 24 h was quantitatively determined with the Cell Counting Kit-8(CCK-8) assay. Immunofluorescence staining and quantitative reverse transcription polymerase chain reaction(qRT-PCR) were used to assess the marker expression in differentiated MSCs. RESULTS: The data showed that both fresh and decellularized lenticules could significantly promote the proliferation of MSCs, compared to that in control(P=0.02 for fresh lenticules, P=0.001 for decellularize ones, respectively). The MSCs seeded on both lenticules were positive for cytokeratin 3(CK3) staining. The expression of CK3 increased 5-fold in MSCs seeded on fresh lenticules and 18-fold on decellularized ones, compared to that in control. There was a significant difference in the expression of CK3 in MSCs seeded on fresh and decellularized lenticules(P<0.001). The expression of CK8 and CK18 was similar in pure MSCs and MSCs seeded on fresh lenticules(P>0.05), while the expression of these markers was decreased in MSCs seeded on decellularized ones. CONCLUSION: These results suggest that the decellularized lenticules might be more suitable for MSCs to differentiate into corneal epithelial cells, which offersthe prospect of a novel therapeutic modality of SMILEderived lenticules in regenerative corneal engineering.

Comparison of two methods used to culture and purify rat retinal Mller cells

AIM:To study two methods for culturing and purifying Sprague-Dawley(SD)rat retinal Muller cells and determine which one is better.METHODS:The passage culture method of Muller cells was respectively carried out by complete pancreatic enzyme digestion method and repeated incomplete pancreatic enzyme digestion method.After culturing retinal cells for one month through these two methods,fluorescence-activated cell sorter(FACS),RT-PCR,and immunohistochemistry technology were performed to examine the enrichment and purity of Muller glial cells,and carried out two-sample approximate t test using SSPS 13.0 to further compare the Muller cell positive rate in both methods.RESULTS:The statistical results showed that the purity of Muller cells was 83.2%±5.16%in group A,and the purity was 98.5%±1.08%in group B.The two-sample approximate t test analysis demonstrated that the difference between group A and group B was statistically significant(t=-9.178,P【0.005).The results clearly exhibited a difference between the purity of Muller cells cultured by the complete pancreatic enzyme digestion method(group A)and the repeated incomplete pancreatic enzyme digestion method(group B).CONCLUSION:Compared with the complete pancreatic enzyme digestion method,this novel method was more efficient and a higher purity of Muller cells could be obtained using this approach.

Increased expression of nestin in human pterygial epithelium

AIM: To investigate the distribution of nestin-positive cells in pterygium, as well as the relationship between nestin-positive cells and proliferative cells in the pathogenesis of pterygium. METHODS: Nine pterygium specimens and 5 normal conjunctiva specimens were investigated. All explanted specimens were immediately immersed in 5-Ethynyl-2'-deoxyuridine, and were subjected to hematoxylin and eosin staining, as well as immunostaining to detect nestin. RESULTS: Small sub-populations of nestin-expressing cells in both normal and pterygial conjunctiva epithelium were found. These were located at the superficial layer of the epithelium, and were significantly increased (P=0.007) and spread out in the pterygial conjunctiva epithelium, even though these cells were mitotically quiescent. CONCLUSION: In pterygium, more nestin-positive cells were present at the superficial layer of the epithelium. With growing scientific evidence that nestin plays an important role in defining various specialized cell types, such as stem cells, cancer cells and angiogenic cells, further investigations on the roles of nestin-expressing cells in pterygium may help to uncover the mechanisms of initiation, development and the prognosis of this disease.

Portable visual and electrochemical detection of hydrogen peroxide release from living cells based on dual-functional Pt-Ni hydrogels

It is important to monitor the intra-/extracellular concentration of hydrogen peroxide(H_(2)O_(2))in biological processes.However,miniaturized devices that enable portable and accurate H_(2)O_(2)measurement are still in their infancy because of the difficulty of developing facile sensing strategies and highly integrated sensing devices.In this work,portable H_(2)O_(2)sensors based on Pt-Ni hydrogels with excellent peroxidase-like and electrocatalytic activities are demonstrated.Thus,simple and sensitive H_(2)O_(2)sensing is achieved through both colorimetric and electrochemical strategies.The as-fabricated H_(2)O_(2)sensing chips exhibit favorable performance,with low detection limits(0.030μM&0.15μM),wide linearity ranges(0.10μM-10.0 mM&0.50μM-5.0 mM),outstanding long-term stability(up to 60 days),and excellent selectivity.With the aid of an M5stack development board,portable visual and electrochemical H_(2)O_(2)sensors are successfully constructed without complicated and expensive equipment or professional operators.When applied to the detection of H_(2)O_(2)released from HeLa cells,the results obtained by the developed sensors are in good agreement with those from an ultraviolet‒visible spectrophotometer(UV‒vis)(1.97μM vs.2.08μM)and electrochemical station(1.77μM vs.1.84μM).

SMILE矫正高度近视的临床疗效及角膜后表面高度改变

目的:观察小切口角膜基质透镜取出术(SMILE)矫正高度近视的安全性、有效性、可预测性、稳定性及角膜后表面高度的变化情况。方法:描述性纵向研究。对2016年中南大学湘雅医院眼科37例高度近视SMILE术后患者67眼(等效球镜度为-10.75^-6.25D)做回顾性分析,于术前、术后1d、1个月、3个月、6个月行裸眼视力(UCVA)、最佳矫正视力(BCVA)、屈光度、眼压、眼轴、角膜地形图等检查。采用广义估计方程对手术前后数据及影响因素进行分析。结果:高度近视患者SMILE术后6个月UCVA(LogMAR)为-0.1(-0.2,0),有效性指数0.83±0.20;BCVA(LogMAR)-0.2(-0.2,-0.2),安全性指数1.03±0.16。术后1、3、6个月近视度数逐渐增加,术后6个月屈光度为-0.25(-0.50,0)D,回退量为-0.25(-0.50,0)D。术后UCVA(LogMAR)与年龄呈正相关,术后屈光度、回退量均与年龄呈负相关。角膜后表面Diff值术前为(0.030±0.006)mm,术后6个月为(0.046±0.012)mm,较术后1个月降低,与术后3个月差异无统计学意义。术后6个月Diff值及ΔDiff值均与角膜组织改变百分比mPTA呈正相关。结论:SMILE矫正高度近视有较好的安全性、有效性、可预测性和稳定性,但在术后6个月内仍有轻度屈光度回退,尤其是年龄较大的患者。术后角膜后表面前移,术后3个月部分恢复,术中组织切削百分比较大者前移量较大。

Genetic Polymorphisms of 22 Novel Autosomal Short Tandem Repeat Loci in Sierra Leone Population

Background:Exploring and identifying novel alleles of noncombined DNAIndex System(CODIS)short tandem repeat(STR)loci in different ethnic groups is important for the establishment of forensic reference databases and study of population genetics.Aim:This study is aimed to explore the genetic polymorphism of 22 non-CODIS autosomal STR loci(D6S477,D18S535,D19S253,D15S659,D11S2368,D20S470,D1S1656,D22-GATA198B05,D8S1132,D4S2366,D21S1270,D13S325,D9S925,D3S3045,D14S608,D10S1435,D12S391,D7S3048,D17S1290,D5S2500,D2S1338,and D16S539)in Sierra Leone population and analyze the population genetic relationships in comparison with otherpopulations.Materialsand ethods:The amples of a total of 495 unrelated individuals(274 females and 221 males)from Sierra Leonewere examined by the Microreader^(TM)23SPID System,and their genetic polymorphisms and associated forensic parameters were calculated.The genetic relationships between Sierra Leonepopulation and other populations were evaluated as well.Results:Atotal of 287 alleles were observed with allelic frequencies ranging from 0.001 to 0.399.The cumulative power of discrimination(CPD)of the 22 autosomal STR loci was 0.99999999999999999999999999999538.The cumulative probability of exclusion(CPE)of the 22 autosomal STR loci was 0.9999998514(CPEdous)and 0.9999999999826(CPEtrios).All of the STR loci reached the Hardy–Weinberg equilibrium after Bonferroni correction.The population genetics analysis results demonstrated that Sierra Leone population exhibited distinctive genetic characteristics compared to those of East Asian populations and it had relatively close genetic distances to the Uygur population.Conclusion:The results of this study could enrich the forensic databases with Sierra Leone population.The 22 STR loci are highly polymorphic and could be used for forensic practice and population genetics studies.

近视患者SMILE术后双眼视觉功能变化

目的:探讨飞秒激光小切口角膜基质透镜取出术(SMILE)后双眼视觉功能的变化及其临床意义。方法:前瞻性临床研究。选取2016年3月至2017年10月在中南大学湘雅医院眼科激光治疗中心接受SMILE的近视患者58例(116眼),术前矫正视力≥5.0。所有患者按术前等效球镜度(SE)分为低中度近视(≥-6.00D)组38例(76眼),高度近视(<-6.00D)组20例(40眼)。所有患者按优势眼分为主导眼组58例(58眼)和非主导眼组58例(58眼)。分别测量术前,术后1周、1个月、3个月的调节功能(包括调节幅度、正/负相对调节、双眼调节灵活度、调节反应)及聚散功能(隐斜、正/负融像范围、集合近点)变化。组间手术前后各时间点数据比较采用重复测量方差分析和两样本t检验。结果:①低中度近视组和高度近视组患者术后1周、1个月、3个月SE均较术前减小(P<0.05)。低中度近视组术后3个月主导眼调节幅度、正相对调节均较术前增大(P<0.05),术后1、3个月双眼调节灵活度较术前增大(P<0.05),高度近视组调节幅度、正/负相对调节、双眼调节灵活度手术前后各时间点比较差异均无统计学意义。低中度近视组与高度近视组主导眼与非主导眼调节幅度手术前后各时间点比较差异均无统计学意义。②低中度近视组与高度近视组术后远/近距隐斜、正/负融像范围、调节性集合/调节比值与术前相比差异均无统计学意义。低中度近视组与高度近视组术后集合近点均较术前增大(P<0.05)。结论:SMILE手术对低中度近视患者术后调节功能及聚散功能均具有积极的影响,但对于高度近视患者,术后双眼视觉功能变化不明显。

SMILE术后不同瞳孔直径下视觉质量的比较

目的:探讨近视患者飞秒激光小切口角膜基质透镜取出术(SMILE)后在4 mm和7 mm瞳孔直径下视觉质量变化及其影响因素。方法:前瞻性临床研究。选取2019年2-5月在中南大学湘雅医院行SMILE的近视和近视散光患者46例,年龄18~36岁,均选择右眼数据用于统计。采用欧卡斯视觉质量分析系统测量术眼在4 mm和7 mm瞳孔直径下术前及术后1周、1个月、3个月的调制传递函数(MTF)、调制传递函数截止频率(MTF cutoff)和斯特列尔比(SR)变化。采用主观质量问卷评估患者主观视觉质量。手术前后视力、屈光度、MTF及SR值等比较采用重复测量方差分析。多元线性回归分析SMILE术后3个月视觉质量变化的影响因素。结果:SMILE术后裸眼视力及等效球镜度(SE)较术前明显改善(F=210.976,P<0.001;F=144.129,P<0.001)。SMILE术后3个月,有效性及安全性指数分别为0.97±0.11、1.00±0.06,SE在±0.5 D内的患者占100%。SMILE手术前后不同时间点4 mm及7 mm瞳孔直径下SR、MTF、MTF cutoff值的总体比较,差异均有统计学意义(均P<0.05)。4 mm瞳孔直径(明视环境)下各空间频率下MTF、MTF cutoff、SR先降后升,术后1个月恢复至术前水平。7 mm瞳孔直径(暗视环境)下,MTF cutoff术后1个月恢复至术前水平,MTF、SR在术后3个月恢复至术前水平。暗视环境下,年龄、术前暗瞳大小为SR及空间频率20、25、30 c/d MTF的影响因素(B_(年龄)=-0.440、-0.409、-0.404、-0.389,均P<0.05;B_(暗瞳)=-0.404、-0.333、-0.371、-0.368,均P<0.05),年龄为MTF cutoff及空间频率5、10、15 c/d MTF的影响因素(B=-0.522,P=0.003;B=-0.403,P=0.008;B=-0.409,P=0.008;B=-0.416,P=0.004)。术前暗瞳大小为夜视力、眩光光晕得分的影响因素(B=-0.370,P=0.020;B=-0.417,P=0.013)。结论:SMILE术后早期明、暗环境下视觉质量较术前有所降低,暗环境下视觉质量与术前暗瞳大小及年龄呈负相关。

Association of interleukin-18 gene polymorphisms with Takayasu arteritis in a Chinese Han population

Background:Interleukin-18(IL18)gene polymorphisms are related to many inflammatory and autoimmune diseases.However,a correlation analysis between IL18-607C/A and-137G/C gene polymorphisms and Takayasu arteritis(TA)is lacking.Methods:This study enrolled 200 patients with TA as the case group and 334 region-,age-,and sex-matched healthy subjects as the control group.We genotyped alleles and genotypes at positions-607 and-137 of the IL18 gene and analyzed the distribution frequencies.Mann-Whitney U test,t test,Chi-squared test and Hardy-Weinberg equilibrium were performed.Results:After adjusting for risk factors,the adjusted odds ratios and 95%confidence intervals at position-607C/A were 0.533,0.391 to 0.880(P=0.010);0.266,0.586 to 1.002(P=0.051);and 0.122,0.552 to 1.420(P=0.613)under the dominant,additive,and recessive models,respectively.For the-137G/C polymorphism,the adjusted odds ratios and 95%confidence intervals were 1.571,1.068 to 2.311(P=0.022);1.467,1.086 to 1.980(P=0.012);and 1.815,0.901 to 3.656(P=0.095)under the dominant,additive,and recessive models,respectively.Moreover,regardless of the model used,we found no statistical difference in distribution frequency between the active and quiescent states of TA for the-607C/A(P=0.355,0.631,and 0.705,respectively)and-137G/C polymorphisms(P=0.205,0.385,and 0.208,respectively).Conclusions:The IL18-607C/A gene polymorphism may decrease the risk of TA,and thus is a protective factor,whereas-137G/C may increase the risk of TA,and thus is a risk factor.However,neither polymorphism was related to activity(active vs.quiescent)of TA.

Sensing nanomaterials of wearable glucose sensors

The metabolic disorder of glucose in human body will cause diseases such as diabetes and hyperglycemia.Hence the determination of glucose content is very important in clinic diagnosing.In recent years,researchers have proposed various non-invasive wearable sensors for rapid and real-time glucose monitoring from human body fluids.Unlike those reviews which discussed performances,detection environments or substrates of the wearable glucose sensor,this review focuses on the sensing nanomaterials since they are the key elements of most wearable glucose sensors.The sensing nanomaterials such as carbon,metals,and conductive polymers are summarized in detail.And also the structural characteristics of different sensing nanomaterials and the corresponding wearable glucose sensors are highlighted.Finally,we prospect the future development requirements of sensing nanomaterials for wearable glucose sensors.This review would give some insights to the further development of wearable glucose sensors and the modern medical treatment.

Enhanced protective immunity against SARS-CoV-2 elicited by a VSV vector expressing a chimeric spike protein

SARS-CoV-2 and SARS-CoV are genetically related coronavirus and share the same cellular receptor ACE2.By replacing the VSV glycoprotein with the spikes(S)of SARS-CoV-2 and SARS-CoV,we generated two replication-competent recombinant viruses,rVSVSARS-CoV-2 and rVSV-SARS-CoV.Using wild-type and human ACE2(hACE2)knock-in mouse models,we found a single dose of rVSV-SARS-CoV could elicit strong humoral immune response via both intranasal(i.n.)and intramuscular(i.m.)routes.Despite the high genetic similarity between SARS-CoV-2 and SARS-CoV,no obvious cross-neutralizing activity was observed in the immunized mice sera.In macaques,neutralizing antibody(NAb)titers induced by one i.n.dose of rVSV-SARS-CoV-2 were eight-fold higher than those by a single i.m.dose.Thus,our data indicates that rVSV-SARS-CoV-2 might be suitable for i.n.administration instead of the traditional i.m.immunization in human.Because rVSV-SARS-CoV elicited significantly stronger NAb responses than rVSV-SARS-CoV2 in a route-independent manner,we generated a chimeric antigen by replacing the receptor binding domain(RBD)of SARS-CoV S with that from the SARS-CoV-2.rVSV expressing the chimera(rVSV-SARS-CoV/2-RBD)induced significantly increased NAbs against SARS-CoV-2 in mice and macaques than rVSV-SARS-CoV-2,with a safe Th1-biased response.Serum immunized with rVSV-SARS-CoV/2-RBD showed no cross-reactivity with SARS-CoV.hACE2 mice receiving a single i.m.dose of either rVSV-SARS-CoV-2 or rVSV-SARSCoV/2-RBD were fully protected against SARS-CoV-2 challenge without obvious lesions in the lungs.Our results suggest that transplantation of SARS-CoV-2 RBD into the S protein of SARS-CoV might be a promising antigen design for COVID-19 vaccines.

Comparing the accuracy of Demirjian and Nolla methods and establishing a new method for dental age estimation in northeastern Chinese children

Dental age estimation plays an important role in the field of clinic medicine and forensic medicine.The Demirjian and Nolla methods are common scoring methods for dental age estimation but there was no research about the comparison of accuracy of these two methods in northeastern Chinese children.Hence,in this study,we compared the accuracy of these two methods to explore more suitable method for our studied population.We collected 535 orthopantomograms from northern Chinese children aged from 6 to 15 years and divided them into training dataset and testing dataset according to the ratio of 7:3.The dental age of training dataset were estimated using Demirjian and Nolla methods,respectively.The results suggested that the mean differences of these two methods were 0.24 and−0.40 years,and mean absolute difference were 0.65 and 0.59 years.Then to further improve the accuracy of dental age assessment,the new improved formulas and dental age conversion tables were established after analyzing the relationship between the sum scores based on Nolla method and chronology age in training dataset.According to the new method used in testing dataset,the minimum value of mean difference(0.00)and mean absolute difference(0.49)were obtained,which are largely smaller than that of Demirjian and Nolla methods.The new developed method and dental age conversion scales may be more suitable dental age estimation method for northeastern Chinese children.

Quasinormal Modes of the Planar Black Holes of a Particular Lovelock Theory

In this work, we study the scalar quasinormal modes of a planar black hole metric in asymptotic anti-de Sitter spacetime derived from a particular Lovelock theory. The quasinormal frequencies are evaluated by adopting the Horowitz-Hubeny method as well as a matrix formalism. Also, the temporal evolution of small perturbations is studied by using finite difference method. The roles of the dimension of the spacetime, the parameter of the metric k, as well as the temperature of the background black hole, are discussed. It is observed that the particular form of the metric leads to quasinormal frequencies whose real parts are numerically insignificant. The black hole metric is found to be stable against small scalar perturbations.

Application of Cameriere’s method for dental age estimation in children in South China

The aim of this study was to evaluate the applicability of Cameriere’s European formula for age estimation in children in South China and to adapt the formula to establish a more suitable formula for these children.Moreover,the performance of dental age estimation based on Cameriere’s method combining the developmental information of permanent teeth(PT)and third molar(TM)was also analysed.Orthopantomographs of 720 healthy children in Group A,and orthopantomographs of 320 children and 280 subadults in Group B were assessed.The samples of Group A were divided into training dataset 1 and test dataset 1,and the samples of Group B were also divided into training dataset 2 and test dataset 2.A South China-specific formula was established based on the training dataset 1,and the comparison of accuracy between the Cameriere’s European formula and the South China-specific formula was conducted with the test dataset 1.Additionally,a PT regression model,a TM regression model,and a combined regression model(PTþTM)were established based on the training dataset 2,and the performance of these three models were validated on the test dataset 2.The Cameriere’s European formula underestimated chronological age with a mean difference(ME)of-0.47±1.11 years in males and-0.69±1.19 years in females.However,the South China-specific formula underestimated chronological age,with a mean difference(ME)of-0.02±0.71 years in males and-0.14±0.73 years in females.Compared with PT model and TM model,the PT and TM combined model obtained the smallest root mean square error(RMSE)of 1.29 years in males and 0.93 years in females.In conclusion,the South China-specific formula was more suitable for assessing the dental age of children in South China,and the PT and TM combined model can improve the accuracy of dental age estimation in children.