[Characteristics of primary ocular symptoms in children with optic pathway glioma at different ages]

Objective: To investigate the characteristics of initial ocular symptoms in children with optic pathway glioma (OPG) at different age stages. Methods: A retrospective case series study was conducted. Clinical data of 16 children with OPG who were diagnosed and treated in the Department of Ophthalmology, Beijing Children's Hospital, Capital Medical University from April 2017 to July 2021 were collected. The initial ocular symptoms, clinical manifestations of the eyes and nervous system, imaging and histopathological features were analyzed, and the differences in initial ocular symptoms between infants and young children aged≤36 months and older children aged>36 months were compared. Results: Of all 16 children included, 9 were male and 7 were female. The onset age was 15.0 (6.3, 56.5) months, and the diagnosis age was 48.0 (11.3, 78.0) months. There were 11 infants and young children, and 5 older children. Eye symptoms were the initial manifestation in 11 cases, including 8 cases of infants and young children (5 cases presented with irregular nystagmus, 2 cases with strabismus, and 1 case with failure to chase visual target), and 3 cases of older children (2 cases presented with decreased vision and 1 case with optic disc edema). The imaging findings showed that optic chiasm-involved OPG accounted for the highest proportion, with 3 cases in older children and 8 cases in infants and young children. Among the 8 children with optic chiasm-involved OPG who underwent surgical treatment, 5 were diagnosed with pilocytic astrocytoma according to histopathological results. Seven children had useful vision saved after treatment, and 1 child had visual loss accompanied by cognitive impairment due to surgery after 4 years of nystagmus. Conclusion: OPG in children often manifests as initial ocular symptoms, with irregular nystagmus being more common in infants and young children, and vision loss being the main symptom in older children.

[Clinical characteristics and treatment of congenital fibrovascular pupillary membranes]

Objective: To investigate the clinical characteristics, surgical approaches and postoperative effects associated with congenital fibrovascular pupillary membranes. Methods: A retrospective study design was used. Thirteen children (13 eyes) with congenital fibrovascular pupillary membranes, treated in Beijing Children's Hospital from January 2014 to December 2017 were included. The morphology of the membrane and the anterior chamber was evaluated using a digital wide-area fundus imaging system. The ophthalmic signs, examination results, operation methods, intraocular pressure and ocular position were analyzed. Results: There were 13 children (13 eyes) were enrolled, including 9 males and 4 females. The age at surgery ranged from 2.0 months to 34.5 months, with an median of 5.1 months. According to the degree of obstruction of the pupil and the intraocular pressure, the eyes were divided into three groups. In the 5 eyes of group A, the pupil membrane did not completely cover the pupil, and the depth of the anterior chamber was normal. Among them, 4 eyes had normal intraocular pressure (9-12 mmHg) (1 mmHg=0.133kPa), and 1 eye had elevated intraocular pressure (18 mmHg). In the 5 eyes of group B, the pupillary membrane completely covered the pupil into a pinhole, the anterior chamber was normal or slightly shallow, and the intraocular pressure was normal (6-16 mmHg). In the 3 eyes of group C, the pupillary membrane completely covered the pupil, the anterior chamber was shallow or disappeared, and the intraocular pressure was high (24-45 mmHg). Membranectomy and pupilloplasty were performed in group A, and trabeculectomy was combined when there was glaucoma; postoperative intraocular pressure was normal (4-10 mmHg). Membranectomy, pupilloplasty and iridectomy were performed in group B; postoperative intraocular pressure was normal (7-13 mmHg). Membranectomy, pupilloplasty, iridectomy and goniosychialysis were performed in group C; after surgery, intraocular pressure was normal in 2 eyes (10 mmHg and 13 mmHg) and 25 mmHg in 1 eye. All eyes were orthophoric before and after operation in group A. In group B, 1 eye was esotropic, 2 eyes were exotropic (worse after surgery in 1 eye), and 2 eyes were orthophoric before surgery. In group C, one eye was esotropic, one eye was exotropic, and one eye was orthophoric before surgery, and all eyes were exotropic after operation. Conclusions: Congenital fibrovascular pupillary membranes are unilaterally a continuation of the iris covering the pupil at different degrees, with or without glaucoma. Surgical treatment should be performed promptly when there is obscuring of the visual axis or incorporating of glaucoma. The main surgical procedures are membranectomy and pupilloplasty and iridectomy. Postoperative intraocular pressure can be well controlled, and strabismus has no improvement. (Chin J Ophthalmol, 2018, 54:849-854).

Bi5FeTi3O15 nanofibers/graphene nanocomposites as an effective counter electrode for dye-sensitized solar cells

The present study reports Bi₅FeTi₃O₁₅ (BFTO) nanofibers/graphene (Gr) nanocomposites (BGr) as counter electrodes (CEs) in dye-sensitized solar cells (DSSCs). BFTO nanofibers with diameters of 40-100 nm were fabricated by sol-gel based electrospinning technique. The microstructure and surface morphology of the BFTO nanofibers and the BGr nanocomposites were characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The electrochemical performances of BGr CEs were comprehensively characterized and investigated. Compared to pristine BFTO, the nanocomposites have a marked improvement in electrocatalytic performance for the reduction of triiodide because of larger surface area and lower transfer resistance on the electrolyte-electrode interface. The maximum power conversion efficiency has reached 9.56%, which is much larger than that of pure BFTO CEs (0.22%).

Liquid immiscibility in an Fe-Cu alloy by molecular dynamics simulation

Liquid-liquid phase segregation in an Fe-Cu melt is investigated by molecular dynamics (MD) simulation based upon a newly developed embedded atom method due to Bonny. The partial pair correlation functions (PPCF) of liquid Fe(50)Cu(50) at a temperature of 1873 K show stronger interaction of homogeneous atom pairs. The coordination number (CN) of Cu-Cu and Fe-Fe in Fe(50)Cu(50) melt is about 11, much higher than that of Fe-Cu. Liquid-liquid phase segregation has also been observed clearly by the atom snapshot method. The calculated enthalpy of mixing is positive in the whole concentration range and the Bhatia-Thornton (BT) structure factor S(CC)(q) increases sharply at lower q, which are all typical features of dense fluid that exhibits a phase segregation tendency. Our present work provides an understanding of atomic-scale phase segregation in liquid Fe-Cu alloy.

Comparative study of growth of Chinese infants: Hong Kong versus Guangzhou

The growth of 174 infants from Hong Kong and 221 infants from Guangzhou from birth to 2 years were compared. Ethnic origins, parental size, and birth weights were similar. Common illnesses in the two groups were upper respiratory tract infection and diarrhoea. The early infant feeding practices were different, with more breastfeeding and earlier introduction of solids in Guangzhou. Compared to those of Hong Kong, Guangzhou babies had lower weight for length in the first year of life. Within the Guangzhou group, babies totally breastfed for the first 2-4 months were heavier than those given rice cereals as supplement and they had less diarrhoea in the first 6 months. Hong Kong infants suffered more diarrhoea than the Guangzhou group. It was concluded that breastfeeding should be promoted and supported in these two cities.