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Railway tracks exhibit a complex, sudden alteration in their cross-sectional configuration. Generating guided waves within thick rail tracks using conventional guided wave transducers is challenging. This research employs directional decomposition to comprehend how guided waves form within the rail. These waves arise from constructive interference between multiple reflected bulk waves, which are induced by point forces on the top surface of the railhead or diffracted from cracks in the rail structure. This study simulates finite-range detection of rail defects using finite element analysis to demonstrate a potential application to the guided wave rail inspection car. The transmitter and a series of monitoring points are located on the same side of the rail defect in the pitch-catch configuration. The transmitting guided waves often hide the small backscatter waves induced by defects. A directional filter extracts the small backscatter signals from the entire received data. A 100 kHz tone burst actuates on the top surface of the rail in three orthogonal directions. Numerical findings demonstrate that vertical and tangential excitations are suitable for detecting defects in the railhead and lower region, while transverse excitation and detection are appropriate for identifying defects in the rail web. The application of directional decomposition provides valuable insights into the complex process of backscatter waves arising from rail track defects.

Joint structures made from plates or shells are frequently used in large constructions, such as oil storage tanks in petrochemical industries. The corrosion-induced metal loss often appears on the back side of the bottom plate supported by ground or sand. The welding residual stress and weight of shell walls accelerate the corrosion. Determining the severity of metal loss under the joint is challenging. This work uses the mode pair technique for nondestructive inspection of inaccessible regions in joint structures. A finite element analysis model simulates the transient responses of the incident and mode-converted fundamental and second harmonic plate waves. The second harmonic s0 plate wave satisfying the phase velocity matching condition accompanies the transmitted fundamental SH0 plate wave. A directional filter identifies every mode-converted plate wave by comparing the frequency spectra with the dispersion curves. Linear ultrasonic guided waves can detect inaccessible regions using mode-converted reflections. The symmetry of the linear mode-converted fundamental plate waves depends on the defect position and geometry, not the size. The mode-converted second harmonic guided wave can achieve better spatial resolution for defect sizing. The nonlinear parameter shows a proportional trend with an increasing thickness reduction. Experimental and numerical evidence reveals nonlinear ultrasonic guided wave technique has the potential for defect detection in joint structures.

This study investigated the signaling mechanism underlying the anti-adhesive effect of all-trans retinoic acid (ATRA) on retinal pigment epithelial ARPE-19 cells. Adhesion kinetics with or without ATRA treatment were profiled by adhesion assay. Surface coating with type IV collagen, fibronectin, laminin, but not type I collagen, significantly enhanced adhesion and spreading of ARPE-19 cells, while ATRA at subtoxic doses (ranging from 10–7to 10–6 M) profoundly suppressed the extracellular matrix-enhanced adhesion ability. Cell attachment on FN activated PI3K/Akt and MAPK cascades, whereas ATRA pretreatment blunted the early phosphorylation of Akt and MAPK signaling mediators including p38 MAPK, JNK1/2, and ERK1/2. Mechanistically, signaling blockade with selective kinase inhibitors demonstrated that all MAPK pathways were involved in the anti-adhesive effect of ATRA, whereas the PI3K inhibitor treatment significantly potentiated the ATRA-suppressed RPE cell adhesion. Moreover, ATRA treatment did not affect intracellular F-actin distribution, but remarkably reduced focal adhesion kinase (FAK) expression and its nuclear localization during ARPE-19 cell attachment. In conclusion, ATRA suppresses the adhering ability of ARPE-19 cells at least in part through MAPK and FAK pathways. Signaling blockade with PI3K inhibitor could be regarded as an alternative modality for treating proliferative vitreoretinopathy.

Incomplete visual recovery, color vision defects, or persistent metamorphopsia may persist even after successful surgery for rhegmatogenous retinal detachment (RRD), especially in cases of RD with macula off, suggesting microstructural macular damage that standard fundus biomicroscopy could not detect. We compared spectral‐domain optical coherence tomography imaging with preoperative and postoperative visual acuity to evaluate the relationship between morphological changes in the outer retina and visual outcome after successful repair of RRD with macula on or off. We enrolled 43 patients (43 eyes) with successful repair of RRD and a minimum 6‐month follow up after surgery in this retrospective research. Patients accepted spectral‐domain optical coherence tomography postoperatively and visual acuity examination preoperatively and postoperatively. The mean age of the patients was 48.74 ± 12.68 years (range: 16–77 years). The mean visual acuity (logarithm of minimal angle of resolution) before surgery was 0.87 ± 0.70. Disrupted ellipsoid zone was noted in one of 11 eyes in the macula‐on group (9.1%) and 19 of 32 eyes in the macula‐off group (59.4%). Disrupted external limiting membrane (ELM) was noted in no eye in the macula‐on group (0%) and 11 of 32 eyes in the macula‐off group (34.4%). The macula‐off group was associated with better postoperative visual gains than the macula‐on group (p= 0.013). Patients with integrity of the ellipsoid zone and ELM were associated with significant visual improvement than patients with disruption of the ellipsoid zone or ELM.

Incomplete visual recovery, color vision defects, or persistent metamorphopsia may persist even after successful surgery for rhegmatogenous retinal detachment (RRD), especially in cases of RD with macula off, suggesting microstructural macular damage that standard fundus biomicroscopy could not detect. We compared spectral-domain optical coherence tomography imaging with preoperative and postoperative visual acuity to evaluate the relationship between morphological changes in the outer retina and visual outcome after successful repair of RRD with macula on or off. We enrolled 43 patients (43 eyes) with successful repair of RRD and a minimum 6-month follow up after surgery in this retrospective research. Patients accepted spectral-domain optical coherence tomography postoperatively and visual acuity examination preoperatively and postoperatively. The mean age of the patients was 48.74 ± 12.68 years (range: 16–77 years). The mean visual acuity (logarithm of minimal angle of resolution) before surgery was 0.87 ± 0.70. Disrupted ellipsoid zone was noted in one of 11 eyes in the macula-on group (9.1%) and 19 of 32 eyes in the macula-off group (59.4%). Disrupted external limiting membrane (ELM) was noted in no eye in the macula-on group (0%) and 11 of 32 eyes in the macula-off group (34.4%). The macula-off group was associated with better postoperative visual gains than the macula-on group (p = 0.013). Patients with integrity of the ellipsoid zone and ELM were associated with significant visual improvement than patients with disruption of the ellipsoid zone or ELM.

Extracellular matrix (ECM) plays an active and complex role in regulating cellular behaviors, including proliferation and adhesion. This study aimed at delineating the adhesion‐induced signaling profiles in cultured human retinal pigment epithelium (RPE) cells and investigating the antiadhesion effect of antiproliferative drugs in this context. RPE R‐50 cells grown on various ECM molecules, such as type I and IV collagens, fibronectin, and laminin, were used for adhesion assay and for examining the phosphorylation profiles of signaling mediators including Akt, extracellular signal‐regulated kinase (ERK) 1/2, and integrin‐linked kinase (ILK) using Western blotting. The cells receiving antiproliferative drug treatment at subtoxic doses were used to evaluate their antiadhesive and suppressive effects on kinase activities. ECM coating enhanced adhesion and spreading of RPE cells significantly. The cellular attachment onto ECM‐coated surfaces differentially induced Akt, ERK1/2, and ILK phosphorylation, and concomitantly increased p53 phosphorylation and cyclin D1 expression, but decreased Bcl‐2/Bax ratios. Treatment with antiproliferative agents, including 5‐fluorouracil, mitomycin C, and daunomycin, at subtoxic doses suppressed the ability of RPE cells to adhere to ECM substratum significantly. This suppression was in part mediated through reduction of integrin β1 and β3 expressions and interfering Akt‐ILK signaling activity. Mechanistically, blockade of PI3K/Akt signaling resulted in the suppressed adhesion of RPE cells to ECM. These findings support the hypothesis that, in addition to their antimitogenic effect, antiproliferative agents also exhibit suppressive effect on the adhesiveness of cultured RPE cells. Moreover, inhibitors of the PI3K/Akt signaling mediator can potentially be used as therapeutic agents for proliferative vitreoretinopathy.

Extracellular matrix (ECM) plays an active and complex role in regulating cellular behaviors, including proliferation and adhesion. This study aimed at delineating the adhesion-induced signaling profiles in cultured human retinal pigment epithelium (RPE) cells and investigating the antiadhesion effect of antiproliferative drugs in this context. RPE R-50 cells grown on various ECM molecules, such as type I and IV collagens, fibronectin, and laminin, were used for adhesion assay and for examining the phosphorylation profiles of signaling mediators including Akt, extracellular signal-regulated kinase (ERK) 1/2, and integrin-linked kinase (ILK) using Western blotting. The cells receiving antiproliferative drug treatment at subtoxic doses were used to evaluate their antiadhesive and suppressive effects on kinase activities. ECM coating enhanced adhesion and spreading of RPE cells significantly. The cellular attachment onto ECM-coated surfaces differentially induced Akt, ERK1/2, and ILK phosphorylation, and concomitantly increased p53 phosphorylation and cyclin D1 expression, but decreased Bcl-2/Bax ratios. Treatment with antiproliferative agents, including 5-fluorouracil, mitomycin C, and daunomycin, at subtoxic doses suppressed the ability of RPE cells to adhere to ECM substratum significantly. This suppression was in part mediated through reduction of integrin β1 and β3 expressions and interfering Akt-ILK signaling activity. Mechanistically, blockade of PI3K/Akt signaling resulted in the suppressed adhesion of RPE cells to ECM. These findings support the hypothesis that, in addition to their antimitogenic effect, antiproliferative agents also exhibit suppressive effect on the adhesiveness of cultured RPE cells. Moreover, inhibitors of the PI3K/Akt signaling mediator can potentially be used as therapeutic agents for proliferative vitreoretinopathy.

The purpose of this study is to investigate the functional and structural outcomes of surgical treatment of eyes with idiopathic macular epiretinal membrane (ERM). Clinical records of 21 patients (22 eyes) who underwent macular ERM removal with at least 6 months of postoperative follow‐up period were reviewed retrospectively. All patients were treated with pars plana vitrectomy and ERM peeling surgery. Fourteen patients also underwent cataract surgery at the same time. Pre‐ and postoperative visual acuity (VA), intraocular pressure (IOP), and macular thickness along with postoperative adverse events were all recorded. The mean follow‐up was 8.5 ± 3.2 months. Three eyes were pseudophakic and 19 eyes were phakic preoperatively. Five phakic eyes undergoing simple ERM peeling surgery had worsened cataracts, and vision was recovered after subsequent cataract extraction surgery. Mean preoperative IOP was 13.1 ± 4.2 mmHg, which did not differ significantly postoperatively (p= 0.228). One patient had increased IOP postoperatively and needed topical antiglaucoma treatment. Thirteen eyes showed visual improvement, and six eyes became worse during the follow‐up. Mean preoperative best‐corrected VA was 0.36 decimal equivalent, which was then converted to logarithm of the minimum angle of resolution (logMAR 0.502 ± 0.259) for statistical analysis; this had improved to a mean of 0.536 decimal equivalent (logMAR 0.38 ± 0.35) at the final follow‐up. Mean central macular thickness (CMT) also significantly declined (p< 0.0001). From an analysis of dividing patients into two subgroups according to clinical severity [macular pucker (MP) and cellophane maculopathy (CM)], measured mean CMT of both groups demonstrated significant reduction at final follow‐up (MP, p< 0.0001; CM, p= 0.005). Mean final best‐corrected VA also reached significant improvement in MP group (p= 0.008). However, in the CM group, no significant change in VA was observed (p= 0.52). Besides, VA measurements in the MP group had improved significantly to that of CM (p= 0.037). The measured CMTs of the MP group had also reduced significantly (p= 0.046) compared with those of the CM group. In conclusion, membrane peeling surgery can lead to a significant reduction of macular edema in patients with idiopathic macular ERM. The advantages of combined peeling and cataract surgery will achieve maximum positive visual outcome.

The purpose of this study is to investigate the functional and structural outcomes of surgical treatment of eyes with idiopathic macular epiretinal membrane (ERM). Clinical records of 21 patients (22 eyes) who underwent macular ERM removal with at least 6 months of postoperative follow-up period were reviewed retrospectively. All patients were treated with pars plana vitrectomy and ERM peeling surgery. Fourteen patients also underwent cataract surgery at the same time. Pre- and postoperative visual acuity (VA), intraocular pressure (IOP), and macular thickness along with postoperative adverse events were all recorded. The mean follow-up was 8.5±3.2 months. Three eyes were pseudophakic and 19 eyes were phakic preoperatively. Five phakic eyes undergoing simple ERM peeling surgery had worsened cataracts, and vision was recovered after subsequent cataract extraction surgery. Mean preoperative IOP was 13.1±4.2mmHg, which did not differ significantly postoperatively (p=0.228). One patient had increased IOP postoperatively and needed topical antiglaucoma treatment. Thirteen eyes showed visual improvement, and six eyes became worse during the follow-up. Mean preoperative best-corrected VA was 0.36 decimal equivalent, which was then converted to logarithm of the minimum angle of resolution (logMAR 0.502±0.259) for statistical analysis; this had improved to a mean of 0.536 decimal equivalent (logMAR 0.38±0.35) at the final follow-up. Mean central macular thickness (CMT) also significantly declined (p<0.0001). From an analysis of dividing patients into two subgroups according to clinical severity [macular pucker (MP) and cellophane maculopathy (CM)], measured mean CMT of both groups demonstrated significant reduction at final follow-up (MP, p<0.0001; CM, p=0.005). Mean final best-corrected VA also reached significant improvement in MP group (p=0.008). However, in the CM group, no significant change in VA was observed (p=0.52). Besides, VA measurements in the MP group had improved significantly to that of CM (p=0.037). The measured CMTs of the MP group had also reduced significantly (p=0.046) compared with those of the CM group. In conclusion, membrane peeling surgery can lead to a significant reduction of macular edema in patients with idiopathic macular ERM. The advantages of combined peeling and cataract surgery will achieve maximum positive visual outcome.

To investigate the relationship between pancreatic cancer (PC) and diabetes mellitus.

The purpose of this study was to investigate the incidence and timing of elevation in intraocular pressure (IOP) after intravitreal injection of triamcinolone acetonide (IVTA). This was a retrospective observational case series that included 52 eyes from 52 patients. All patients received intravitreal injection with 4 mg of triamcinolone acetonide. Significant IOP elevation was defined as pressure greater than 21 mmHg. There were 26 males and 26 females included in this study. The mean age was 59.4 years. The mean IOP at baseline and postoperative mean highest IOP were 14.6 mmHg and 21.5 mmHg, respectively. There were 19 (36.5%) patients who experienced significant IOP elevation at a mean of 26.0 days after IVTA. IOP was well‐controlled by topical antiglaucoma medication in 17 of these 19 patients. IOP elevation after intravitreal injection with 4 mg of triamcinolone acetonide is not a rare finding. This phenomenon usually starts approximately 1 month after IVTA. Patients considering this treatment should be fully informed of this known adverse effect.

The purpose of this study was to investigate the incidence and timing of elevation in intraocular pressure (IOP) after intravitreal injection of triamcinolone acetonide (IVTA). This was a retrospective observational case series that included 52 eyes from 52 patients. All patients received intravitreal injection with 4 mg of triamcinolone acetonide. Significant IOP elevation was defined as pressure greater than 21 mmHg. There were 26 males and 26 females included in this study. The mean age was 59.4 years. The mean IOP at baseline and postoperative mean highest IOP were 14.6 mmHg and 21.5 mmHg, respectively. There were 19 (36.5%) patients who experienced significant IOP elevation at a mean of 26.0 days after IVTA. IOP was well-controlled by topical antiglaucoma medication in 17 of these 19 patients. IOP elevation after intravitreal injection with 4 mg of triamcinolone acetonide is not a rare finding. This phenomenon usually starts approximately 1 month after IVTA. Patients considering this treatment should be fully informed of this known adverse effect.

There have been concerns that there may be an increased incidence of iris neovascularization (NV) following lens removal in patients with proliferative diabetic retinopathy (PDR). In this study, we retrospectively compared vitrectomy alone and vitrectomy combined with phacoemulsification (phacovitrectomy) and intraocular lens implantation regarding both complications and results. Fifty‐three eyes for vitrectomy group and 31 eyes for phacovitrectomy group were included. Postoperative iris and angle NV were found in eight (15.1%) eyes in the first group and no (0%) eyes in the second. The incidence was significantly lower (p< 0.05) in the phacovitrectomy group. The final vision gain of one or more lines was found in 17 (32.1%) and 21 (67.7%) eyes, respectively. There was significantly better vision improvement in the phacovitrectomy group. We consider the combined procedure to be useful as an alternative surgical treatment for patients with PDR and cataract formation.

There have been concerns that there may be an increased incidence of iris neovascularization (NV) following lens removal in patients with proliferative diabetic retinopathy (PDR). In this study, we retrospectively compared vitrectomy alone and vitrectomy combined with phacoemulsification (phacovitrectomy) and intraocular lens implantation regarding both complications and results. Fifty-three eyes for vitrectomy group and 31 eyes for phacovitrectomy group were included. Postoperative iris and angle NV were found in eight (15.1%) eyes in the first group and no (0%) eyes in the second. The incidence was significantly lower ( p< 0.05) in the phacovitrectomy group. The final vision gain of one or more lines was found in 17 (32.1%) and 21 (67.7%) eyes, respectively. There was significantly better vision improvement in the phacovitrectomy group. We consider the combined procedure to be useful as an alternative surgical treatment for patients with PDR and cataract formation.

We designed a case series study to evaluate the outcome of intravitreal triamcinolone acetonide for the treatment of macular edema due to branch retinal vein occlusion (BRVO). The prospective comparative nonrandomized clinical interventional study included 27 patients (27 eyes) with macular edema due to BRVO. The study group consisted of 16 patients who had accepted an intravitreal injection (IVI) of 4 mg triamcinolone acetonide. The control group included 11 patients without IVI of triamcinolone acetonide. The mean follow‐up was 103.00 36.24 days in the study group and 94.55 36.31 days in the control group. In the study group, visual acuity measurements improved significantly (p0.001) from 0.77 0.43 logarithm of minimal angle of resolution (logMAR) preoperatively to a best postoperative visual acuity of 0.44 0.43 logMAR. Fourteen eyes (87.5%) gained improvement in visual acuity, with 10 eyes (62.5%) showing an increase in visual acuity of at least two Snellen lines. All 16 patients showed significant macular edema resolution in optical coherence tomography examination (p0.001) and perivascular leakage decrease in fluorescein angiography post‐IVI. In the control group, baseline best‐corrected visual acuity and best‐corrected visual acuity during the follow‐up did not vary significantly (p0.294). In conclusion, IVI of triamcinolone acetonide can lead to an increase in visual acuity and a resolution of macular edema in patients with BRVO.

Human retinal pigment epithelial (RPE) cell cultures are usually obtained from donor eyes; isolation and culture of RPE cells obtained by evisceration has not been reported previously. The present study attempted to isolate and cultivate RPE cells from evisceration specimens obtained from two cases with severe ocular trauma. Two different isolation methods, explantation and enzymatic dissociation, were used. In Case 1, RPE cells grew from the explants, but were contaminated with other cells such as fibroblasts and melanocytes, and no pure RPE cultures were obtained by explantation. In Case 2, RPE cells were separated from choroids using 0.25% trypsin before plating for culture, which effectively eliminated contaminating cells. A pure RPE culture was obtained and cultured with F12 medium supplemented with 30% fetal bovine serum. With this enzymatic dissociation method, cultured RPE cells grew to confluence in primary culture and could be maintained in culture for five passages. Cultured RPE cells were identified by the presence of cytokeratin expression, as shown by immunocytochemical staining. These isolation and culture methods provide alternative sources for human RPE cells and could be useful in studies of the cell biology and pathophysiology of human RPE cells.

Summary: After introduction of the broad host range plasmid RP4 inXanthomonas campestris pv.citri strain XAS4501 twoXanthomonas transposable elements, ISXC4 and ISXC5, were isolated. These elements were found to be capable of transposition inEscherichia coli. Restriction analysis, DNA hybridization and heteroduplex experiments revealed that ISXC4 and ISXC5 are about 5.55 and 6.95 kb in size, respectively, possess inverted repeats about 50±18 bp in length and share DNA homology in their left (5.0 kb) and right (0.6 kb) ends. ISXC4 and ISXC5 were found to originate from plasmids pXW45N and pXW45J, which are indigenous replicons inX. campestris pv.citri strain XW45.

[is0p9]To investigate the relationship between cutaneous microcirculation and retinopathy in diabetes mellitus, we studied by dynamic capillaroscopy 35 diabetes mellitus patients, including 10 patients without retinopathy, 10 patients with background retinopathy, and 15 patients with proliferative retinopathy. We found that (1) cutaneous and retinal microcirculation in diabetes mellitus in long-term diabetes mellitus, regressional rather than proliferational changes occurred in skin vasculature as compared to that in retina; (2) functional impairments of cutaneous microcirculation, that is, decreased resting capillary blood cell velocity, peak blood cell velocity, and prolonged time to peak capillary blood cell velocity by dynamic capillaroscopy, could be detected in diabetes mellitus patients without retinopathy; (3) the degree of tortouosity of capillaries, impairment in peak capillary blood cell velocity, and time to peak capillary blood cell velocity of cutaneous microcirculation were significantly correlated with the gravity of retinopathy in diabetes mellitus patients; (4) abnormal leakage of fluorescence in cutaneous microcirculation appeared in diabetes mellitus patients with or without abnormal fluorescein angiography in retina. In conclusion, dynamic capillaroscopy used in concert with ophthalmoscopy and fluorescein angiography can facilitate a comprehensive examination of vasculopathy in diabetes mellitus.

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