A novel analysis of Scheimpflug total corneal refractive power following corneal cross-linking in mild to moderate keratoconus.

AIM: To detect an earlier improvement in mild to moderate keratoconus following corneal cross-linking (CXL) with total corneal refractive power (TCRP) using ray tracing method. METHODS: A total of 40 eyes of 30 consecutive patients who underwent CXL for progressive keratoconus were retrospectively enrolled. The following keratometric parameters provided by Pentacam HR, including maximum keratometry (Kmax), steepest keratometry (Ksteep), 3 mm zonal TCRP centered over corneal apex (TCRPapex,zone 3 mm), zonal mean keratometry and TCRP centered over corneal cone (Kmcone,zone and TCRPcone,zone 1, 2, 3 mm) were evaluated preoperatively and 1, 3, 6, and 12mo postoperatively. Groups 1 and 2 were defined based on Kmax at postoperative 1mo as improved (the initial improvement group) or worsen (the initial deterioration group) compared to the preoperative level. RESULTS: In the overall group, only keratometric parameters based on ray tracing method displayed significant improvement early at 3mo postoperatively, in which TCRPcone,zone 1 mm and 2 mm exhibited the largest flattening (0.57 D and 0.53 D, respectively). In Group 1, only Kmax, Kmcone,zone 2 mm and TCRPcone,zone 2 mm showed significant improvement initially at 1mo postoperatively, in which Kmax exhibited the largest improvement (1.05 D), followed by TCRPcone,zone 2 mm (0.82 D). In Group 2, only keratometric parameters based on ray tracing method and Kmcone,zone 3 mm showed slight but not significant improvement early at 3mo, in which TCRPcone,zone 3 mm displayed the most improvement (0.19 D), followed by TCRPcone,zone 2 mm (0.15 D). CONCLUSION: The findings indicate that a 2 mm zonal TCRP centered over Kmax could earlier detect keratometric improvement by CXL compared to other commonly used parameters in mild to moderate keratoconic eyes.

Bioinspired Color-Changeable Organogel Tactile Sensor with Excellent Overall Performance.

Inspired by chameleons' structural color regulation capability, a simple, but effective, swelling method is proposed for the first time to prepare an ionic polyacrylamide (PAAm) organogel for simultaneous tactile sensing and interactive color changing. The PAAm organogel obtained by swelling the PAAm scaffold in the dimethyl sulfoxide solution of organic electrochromic material (OECM) shows an extremely large stretchability with an elongation of 1600%, a supersoftness with a compressive modulus of 7.2 kPa, an excellent transmittance up to 90%, and a very fast response time of 0.5 s combined with the characteristic of interactive color changing. The PAAm organogel also suggests a universal design ability to tailor coloration spectra for tactile sensors via simply changing the type and content of OECM. The tactile sensor based on a PAAm organogel is capable of serving as a wearable device for precisely tracing human body motion performance and directly visualizing the stress distribution via interactive color changing capability. It is demonstrated that the swelling method proposed here is a simple and practical strategy to prepare ionic organogels with both piezo-resistive and electrochromic effects.

Clinical observations of iridociliary cysts and their changes after implantable collamer lens implantation in myopic patients.

AIM: To observe the characteristics of iridociliary cysts in myopic patients and evaluate the influences on the position and safety of implantable collamer lens (ICL) after surgery. METHODS: Totally 270 eyes of 135 patients who underwent ICL surgery for the corrections of myopia were included in this study. Preoperative and postoperative morphology of iridociliary cysts were observed in ultrasonic biomicroscopy (UBM) image. RESULTS: A total of 138 iridociliary cysts were found in 88 eyes of 50 patients among 270 eyes of 135 patients before surgery (37%). Twenty-five patients had cysts in one eye (50%) and 25 had cysts in both eyes (50%). The prevalence of iridociliary cysts was negatively correlated with age, but no gender difference (P>0.05). The incidence of iridociliary cysts was much less in eyes with myopia greater than -9.00 D (P<0.05). The diameter of the largest cyst was 1.96 mm and the smallest cyst was 0.24 mm, with a majority within the range of 0.5 to 1.0 mm. Most of the cysts were located in the inferior temporal quadrant. One year after ICL implantation, 51 iridociliary cysts (37%) remained unchanged, 47 cysts (34%) decreased in size, and 40 cysts (29%) disappeared. Most of cysts that changed after surgery were smaller than 1.0 mm (P<0.05) and located in the nasal and temporal sides around the haptics of implantable lens. All the ICL were in their original position. CONCLUSION: Iridociliary cysts are commonly seen in myopic eyes. The cysts have no impact on the safety of ICL surgery. Some cysts may decrease in size or disappear after ICL implantation.

Induction of differentiation of human stem cells ex vivo: Toward large-scale platelet production.

Platelet transfusion is one of the most reliable strategies to cure patients suffering from thrombocytopenia or platelet dysfunction. With the increasing demand for transfusion, however, there is an undersupply of donors to provide the platelet source. Thus, scientists have sought to design methods for deriving clinical-scale platelets ex vivo. Although there has been considerable success ex vivo in the generation of transformative platelets produced by human stem cells (SCs), the platelet yields achieved using these strategies have not been adequate for clinical application. In this review, we provide an overview of the developmental process of megakaryocytes and the production of platelets in vivo and ex vivo, recapitulate the key advances in the production of SC-derived platelets using several SC sources, and discuss some strategies that apply three-dimensional bioreactor devices and biochemical factors synergistically to improve the generation of large-scale platelets for use in future biomedical and clinical settings.

Exogenous R-Spondin1 Induces Precocious Telogen-to-Anagen Transition in Mouse Hair Follicles.

R-spondin proteins are novel Wnt/ß-catenin agonists, which signal through their receptors leucine-rich repeat-containing G-protein coupled receptor (LGR) 4/5/6 and substantially enhance Wnt/ß-catenin activity. R-spondins are reported to function in embryonic development. They also play important roles in stem cell functions in adult tissues, such as the intestine and mammary glands, which largely rely on Wnt/ß-catenin signaling. However, in the skin epithelium and hair follicles, the information about R-spondins is deficient, although the expressions and functions of their receptors, LGR4/5/6, have already been studied in detail. In the present study, highly-enriched expression of the R-spondin family genes (Rspo1/2/3/4) in the hair follicle dermal papilla is revealed. Expression of Rspo1 in the dermal papilla is specifically and prominently upregulated before anagen entry, and exogenous recombinant R-spondin1 protein injection in mid-telogen leads to precocious anagen entry. Moreover, R-spondin1 activates Wnt/ß-catenin signaling in cultured bulge stem cells in vitro, changing their fate determination without altering the cell proliferation. Our pioneering study uncovers a role of R-spondin1 in the activation of cultured hair follicle stem cells and the regulation of hair cycle progression, shedding new light on the governance of Wnt/ß-catenin signaling in skin biology and providing helpful clues for future treatment of hair follicle disorders.

[Temperature Effects on Erbium Doped Optical Fibers Properties].

In scientific research and engineering application, improving the power of fiber device is an important topic, which leads to observably rise of temperature in fiber core at the same time. In this paper, Thermal effect and its influence on absorption spectrum and lifetime of Erbium-doped fiber are studied with numerical modeling. Lorentz broadening of sub-levels is used to build the mathematical relationship between temperature and absorption spectrum. The McCumber Theory is applied to deduce the lifetime of Erbium-doped fiber in different temperature. Temperature experiments of absorption and emission spectrum from 25 to 900 ℃ are carried out, which show that the wavelength of absorption peak near 980nm increase at rate of 0.625 nm/100 ℃, the ratio of absorption peak near 1 530 nm declines at a rate of 0.001 9 dB·(m℃)-1 and the broadband of absorption spectrum near 1 530 nm increase with rising temperature. The linear variation of lifetime and peak absorption in experiment proves that the theoretical model is reasonable when the temperature is below 600 ℃.

[Gamma Radiation Effects on Erbium-Doped Optical Fibers Properties].

In order to promote the research on erbium-doped fiber's anti-radiation properties and fully grasp variation laws of erbium-doped fiber's properties under radiation, theoretical analysis on how irradiation effect erbium-doped Fiber based on model of color centers was conducted. The performance changes of erbium-doped fiber that may occur during irradiation were predicted. According to working principle and application characteristics, online real-time monitoring of 980 nm wave band loss spectra, 1 550 nm wave band loss spectra, luminescence spectra of two different types(EDF-L-980 and MP980) of erbium-doped fiber as well as recovery measuring after radiation were carried out,. Studies showed that spectral characteristics of both types have similar variation trends during radiation. Losses at 980 and 1 530 nm wave band increase monotonically with dose, and the relationship is approximately linear at absorption peak of 980 and 1 530 nm; luminescence spectra intensity decreases monotonically with dose, and energy of luminescence spectra is shifting to long wavelengths, while its mean wavelength and bandwidth increasing substantially. The relationship between luminescence intensity and dose is also approximately linear at luminescence peak of 1 530 nm. Erbium-doped fiber's spectral characteristics recovered modestly after radiation, but to a limited extent of less than 40% for all parameters. The experiment result is in good agreement with theoretical analysis and prediction, so rationality of theoretical explanation of erbium-doped fiber's performance changes during radiation has been proven.

[Effect of critical process parameters on luminescence properties of Eu2+/Dy3+ co-doped high silica luminescence glass].

In the present work, Eu2+/Dy3+ co-doped high silica glasses with different process parameters were prepared and the effect of critical process parameters including phase separation temperature, solution concentration and sintering temperature on the luminescence properties of Eu2+/Dy3+ co-doped high silica glasses was investigated by means of measuring pore surface parameters of porous glasses, emission spectra, infrared absorption spectra and densities of high silica glasses. Pore structure parameters of porous glass samples and emission spectra of corresponding high silica glass samples with different phase separation temperatures show that the phase separation temperature has indirect effect on luminescence properties of high silica glass by influencing specific surface area value of corresponding porous glass. Specific surface area of porous glass changes when phase separation temperature changes. High silica glass achieves maximum emission intensity when the maximum specific surface area of porous glass is obtained. Luminescence intensity of high silica glass increases when specific surface area of porous glass increases. Emission spectra of high silica glass samples with different solution concentrations show that the emission intensities of Eu2+ and Dy3+ in high silica glass are enhanced with the increase in the Dy3+ concentration in solution; when the Dy3+ concentration is beyond 0.1 mol x L(-1), the emission intensities of Eu2+ and Dy3+ in high silica glass are both decreased due to the occurring of concentration quench of Dy3+ in the glass. Emission spectra and infrared absorption spectra of high silica glass samples with different sintering temperatures show that the emission intensity of high silica glass is increased with the increase in the sintering temperature because the content of residual hydroxyl groups -OH in the glass is decreased; when the sintering temperature is beyond 1000 degrees C, the high silica glass exhibits crystalline and the luminescence intensity decreases.

Estrogen leads to reversible hair cycle retardation through inducing premature catagen and maintaining telogen.

Estrogen dysregulation causes hair disorder. Clinical observations have demonstrated that estrogen raises the telogen/anagen ratio and inhibits hair shaft elongation of female scalp hair follicles. In spite of these clinical insights, the properties of estrogen on hair follicles are poorly dissected. In the present study, we show that estrogen induced apoptosis of precortex cells and caused premature catagen by up-regulation of TGF ß2. Immediately after the premature catagen, the expression of anagen chalone BMP4 increased. The up-regulation of BMP4 may further function to prevent anagen transition and maintain telogen. Interestingly, the hair follicle stem cell niche was not destructed during these drastic structural changes caused by estrogen. Additionally, dermal papilla cells, the estrogen target cells in hair follicles, kept their signature gene expressions as well as their hair inductive potential after estrogen treatment. Retention of the characteristics of both hair follicle stem cells and dermal papilla cells determined the reversibility of the hair cycle suppression. These results indicated that estrogen causes reversible hair cycle retardation by inducing premature catagen and maintaining telogen.

NASA-approved rotary bioreactor enhances proliferation of human epidermal stem cells and supports formation of 3D epidermis-like structure.

The skin is susceptible to different injuries and diseases. One major obstacle in skin tissue engineering is how to develop functional three-dimensional (3D) substitute for damaged skin. Previous studies have proved a 3D dynamic simulated microgravity (SMG) culture system as a "stimulatory" environment for the proliferation and differentiation of stem cells. Here, we employed the NASA-approved rotary bioreactor to investigate the proliferation and differentiation of human epidermal stem cells (hEpSCs). hEpSCs were isolated from children foreskins and enriched by collecting epidermal stem cell colonies. Cytodex-3 micro-carriers and hEpSCs were co-cultured in the rotary bioreactor and 6-well dish for 15 days. The result showed that hEpSCs cultured in rotary bioreactor exhibited enhanced proliferation and viability surpassing those cultured in static conditions. Additionally, immunostaining analysis confirmed higher percentage of ki67 positive cells in rotary bioreactor compared with the static culture. In contrast, comparing with static culture, cells in the rotary bioreactor displayed a low expression of involucrin at day 10. Histological analysis revealed that cells cultured in rotary bioreactor aggregated on the micro-carriers and formed multilayer 3D epidermis structures. In conclusion, our research suggests that NASA-approved rotary bioreactor can support the proliferation of hEpSCs and provide a strategy to form multilayer epidermis structure.