低价锆氧化物Zr_(3)O的结构、热力学和弹性性质第一性原理研究

采用第一性原理系统地研究3种Zr_(3)O晶形(空间群分别为R3c(斜方六面体)、R32(斜方六面体)和P6322(六面体))的晶格动力学及其与温度相关的热力学和力学性质。计算得到的3种Zr_(3)O晶形的晶体结构参数与实验结果一致。此外,证明3种Zr_(3)O结构在动力学和热力学上均具有稳定性。获得了3种Zr_(3)O晶形在0~1500 K温度范围内的熵、焓、吉布斯自由能、比热容、热膨胀系数和弹性模量等性质。发现3种Zr_(3)O晶形在0K时的相对稳定性顺序为Zr_(3)O(R3c)>Zr_(3)O(R32)>Zr_(3)O(P6_(3)22);然而,在50 K时Zr_(3)O(R3c)转变成Zr_(3)O(R32),在540K时转变为Zr_(3)O(P6_(3)22)。相较于其他2种Zr_(3)O相,Zr_(3)O(R32)表现出更优越的力学性能。

TGFBI gene mutation analysis in a Chinese pedigree of Avellino corneal dystrophy

AIM: To analyze phenotype and genotype of a Chinese pedigree with Avellino corneal dystrophy (ACD). METHODS: Complete ophthalmic EX aminations were performed on all the family members. Exons of TGFBI were amplified by polymerase chain reaction, sequenced, and compared with a reference database. RESULTS: A single heterozygous G>A(R124H) point mutation was identified in exon 4 of TGFBI in three affected members and two unaffected children who were offsprings of the affected members, but not in the other family members. CONCLUSION: Mutation R124H in TGFBI was identified in this pedigree and appeared to be the disease causing mutation. Atypical phenotype and low penetrance was observed in this pedigree..

A mutated CRYGD associated with congenital coralliform cataracts in two Chinese pedigrees

AIM:To investigate the causal gene mutation and clinical characteristics for two Chinese families with autosomal dominant congenital coralliform cataract.METHODS:Two Chinese pedigrees with congenital cataract were investigated.Routine ophthalmic examinations were performed on all patients and non-affected family members.Peripheral blood samples were collected,and the genomic DNAs were extracted.The coding regions of proband’s DNAs were analyzed with cataract gene panel.The identified mutation was amplified by polymerase chain reaction,and automated sequencing was performed in other members of two families to verify whether the mutated gene was co-segregated with the disease.RESULTS:Congenital coralliform cataract was inherited in an autosomal dominant mode in both pedigrees.For each family,more than half of the family members were affected.All patients presented with severe visual impairment after birth as a result of bilateral symmetric coralliform lens opacification.An exact the same defect in the same gene,a heterozygous mutation of c.70 C>A(p.P24 T)in exon 2 of γ Dcrystallin gene,was detected in both probands from each family.Sanger sequencing analysis demonstrated that the mutated CRYGD was co-segregated in these two families.CONCLUSION:A c.70 C>A(p.P24 T)variant in CRYGD gene was reconfirmed to be the causal gene in two Chinese pedigrees.It is known that mutated CRYGD caused most of the congenital coralliform cataracts,suggesting that the CRYGD gene is associated with coralliform congenital cataract.

Single nucleotide polymorphism of MYOC affected the severity of primary open angle glaucoma

AIM: To detect the mutations in two candidate genes, myocilin (MYOC ) and cytochrome P450 1B1 (CYP1B1 ), in a Chinese family with primary open angle glaucoma (POAG). ·METHODS:Thefamilywascomposedofthreemembers, the parents and a daughter. All members of the family underwent complete ophthalmologic examinations. Exons of MYOC and CYP1B1 genes were screened for sequence alterations by polymerase chain reaction (PCR) and direct DNA sequencing. ·RESULTS: The mother was the proband, she was diagnosed as POAG in both eyes. Her daughter was diagnosed as juvenile -onset POAG. The father was asymptomatic. One MYOC heterozygous mutation c.1150 G 】A (D384N) in exon 3 was identified in the mother, another MYOC heterozygous variation c.1058 C】T (T353I) in exon 3 was identified in the father, and the daughter inherited both of the variations. Meanwhile, three single nucleotide polymorphisms (SNPs) in CYP1B1 gene were found in the family. ·CONCLUSION: The D384N mutation of MYOC has been reported as one of disease-causing mutations in POAG, whereas T353I variation of MYOC was thought as a high risk factor for POAG. The two variations of MYOC were first reported in one juvenile -onset POAG patient whopresented with more severe clinical manifestations, suggesting that T353I polymorphism of MYOC may be associated with the severity of POAG.

Evaluation of trabecular meshwork-specific promoters in vitro and in vivo using scAAV2 vectors expressing C3 transferase

AIM:To evaluate the potential of two trabecular meshwork(TM)-specific promoters,Chitinase 3-like 1(Ch3L1)and matrix gla protein(MGP),for improving specificity and safety in glaucoma gene therapy based on self-complementary AAV2(scAAV2)vector technologies.METHODS:An scAAV2 vector with C3 transferase(C3)as the reporter gene(scAAV2-C3)was selected.The scAAV2-C3 vectors were driven by Ch3L1(scAAV2-Ch3L1-C3),MGP(scAAV2-MGP-C3),enhanced MGP(scAAV2-eMGP-C3)and cytomegalovirus(scAAV2-CMV-C3),respectively.The cultured primary human TM cells were treated with each vector at different multiplicities of infections.Changes in cell morphology were observed by phase contrast microscopy.Actin stress fibers and Rho GTPases/Rho-associated protein kinase pathway-related molecules were assessed by immunofluorescence staining,real-time quantitative polymerase chain reaction and Western blot.Each vector was injected intracamerally into the one eye of each rat at low and high doses respectively.In vivo green fluorescence was visualized by a Micron III Retinal Imaging Microscope.Intraocular pressure(IOP)was monitored using a rebound tonometer.Ocular responses were evaluated by slit-lamp microscopy.Ocular histopathology analysis was examined by hematoxylin and eosin staining.RESULTS:In TM cell culture studies,the vectormediated C3 expression induced morphologic changes,disruption of actin cytoskeleton and reduction of fibronectin expression in TM cells by inhibiting the Rho GTPases/Rhoassociated protein kinase signaling pathway.At the same dose,these changes were significant in TM cells treated with scAAV2-CMV-C3 or scAAV2-Ch3L1-C3,but not in cells treated with scAAV2-eMGP-C3 or scAAV2-MGP-C3.At lowinjected dose,the IOP was significantly decreased in the scAAV2-Ch3L1-C3-injected eyes but not in scAAV2-MGPC3-injected and scAAV2-eMGP-C3-injected eyes.At highinjected dose,significant IOP reduction was observed in the scAAV2-eMGP-C3-injected eyes but not in scAAV2-MGP-C3-injected eyes.Similar to scAAV2-CMV-C3,scAAV2-Ch3L1-C3 vector showed efficient transduction both in the TM and corneal endothelium.In anterior segment tissues of scAAV2-eMGP-C3-injected eyes,no obvious morphological changes were found except for the TM.Inflammation was absent.CONCLUSION:In scAAV2-transduced TM cells,the promoter-driven efficiency of Ch3L1 is close to that of cytomegalovirus,but obviously higher than that of MGP.In the anterior chamber of rat eye,the transgene expression pattern of scAAV2 vector is presumably affected by MGP promoter,but not by Ch3L1 promoter.These findings would provide a useful reference for improvement of specificity and safety in glaucoma gene therapy using scAAV2 vector.

Experimental Tibetan monkey domestication and its application for intraocular pressure measurement

AIM: To train Tibetan monkey (Macaca thibetana) for intraocular pressure (IOP) measurement in conscious state and obtain normal IOP in conscious Tibetan Macaque. METHODS: The training was based on award-conditioned behavior. Food stimulation and human-animal interaction were used in this training. RESULTS: Trained Tibetan monkeys calmly accepted IOP measurement by the TonoVete (R) rebound tonometer without sedation or anesthesia and their IOP values were similar to other primates. CONCLUSION: Human-cultivated Thibetan monkeys are tamable, and can be used for biomedical research such as ophthalmic research without anesthesia.

Studies of a pedigree with limbal dermoid cyst

AIM: To study clinical features and gene mutations within the paired-like homeodomain transcription factor 2 (PITX2) gene in a pedigree of bilateral limbal dermoids. METHODS: Complete eye examinations have been performed on each individual of the family. Exons of paired-like homeodomain transcription factor 2 ( PITX2)were amplified by polymerase chain reaction, sequenced, and compared with a reference database. RESULTS: We described the phenotype, clinic findings in a family with two affected members. The masses of the proband's eyes were excised surgically demonstrating a dermoid cyst by histopathological examination. No mutation was detected in the gene PITX2 in this pedigree. CONCLUSION: A family of limbal dermoid cyst was reported. In addition, no pathogenic sequence variations were found in PITX2, indicating that this phenotype in this family is a distinctive entity.

A case of 9p deletion syndrome with congenital infantile glaucoma,effective method of diagnosis,and treatment

Dear Editor,I am Dr.Jia X from the Department of Ophthalmology,Second Xiangya Hospital,Central South University,Changsha,China.I write to present a rare case report of 9p deletion syndrome with congenital infantile glaucoma in an infant,accompanying with an effective method of both diagnosis and treatment.

Novel homozygous ADAMTS17 missense variant in Weill-Marchesani syndrome

AIM: To explore the phenotype and genotype of WeillMarchesani syndrome(WMS) in a Chinese family and review related literature.METHODS: Three WMS patients and other unaffected individuals in this family with a history of consanguineous marriage were included in this study. Medical history, comprehensive ophthalmic examinations, and systemic evaluation, as well as whole exome and Sanger sequencing of specific genomic regions, were performed. RESULTS: The three affected siblings presented with short stature, brachydactyly and ocular disorders, including very shallow anterior chamber, high myopia, microspherophakia lens subluxation with stretched zonules and glaucoma. Genetic analysis verified a homozygous missense mutation(c.2983C>T: p. Arg995Trp) in ADAMTS17,which was correlated with the diseases in this family, indicating an autosomal recessive inherited manner of WMS. This review aims to summarize the mutation sites of WMS genes, so as to prevent the disease and better guide clinical diagnosis and treatment.CONCLUSION: A novel homozygous missense variant of ADAMTS17 is identified in a WMS family with a history of consanguineous marriage. Our study expands the range of mutations associated with WMS and deepens our understanding of pathology in disease associated with ADAMTS17 variants.

Formation behavior of CaTiO_3 during electrochemical deoxidation of ilmenite concentrate to prepare Fe–Ti alloy

The formation behavior of CaTiO3 during electro-deoxidization of ilmenite concentrate to prepare Fe–Ti alloy was investigated by experiments and simulation.The results indicate that the formation and decomposition of intermediate products,CaTiO3,are inevitable steps during electro-deoxidization of ilmenite concentrate.CaTiO3 can be generated through the hydrolyzation of molten salt and electrochemistry reaction during electrochemical process.The main reason for the generation of CaTiO3 is the electrochemistry reaction between Ca^2＋ from molten salt and TiO2 in the cathode.With the proceeding of the electro-deoxidization,CaTiO3 is further electrolyzed to form titanium sub-oxide.The current efficiency can be improved when CaTiO3 forms in the cathode by adding CaCO3 during sintering process.