Chimeric deletion mutation of rpoC2 underlies the leaf-patterning of Clivia miniata var. variegata.

KEY MESSAGE: The deletion mutated rpoC2 leads to yellow stripes of Clivia miniata var. variegata by down regulating the transcription of 28 chloroplast genes and disturbing chloroplast biogenesis and thylakoid membrane development. Clivia miniata var. variegata (Cmvv) is a common mutant of Clivia miniata but its genetic basis is unclear. Here, we found that a 425 bp deletion mutation of chloroplast rpoC2 underlies the yellow stripes (YSs) of Cmvv. Both RNA polymerase PEP and NEP coexist in seed-plant chloroplasts and the ß″ subunit of PEP is encoded by rpoC2. The rpoC2 mutation changed the discontinuous cleft domain required to form the PEP central cleft for DNA binding from 1103 to 59 aa. RNA-Seq revealed that 28 chloroplast genes (cpDEGs) were all down-regulated in YSs, of which, four involved in chloroplast protein translation and 21 of photosynthesis system (PS)I, PSII, cytochrome b6/f complex and ATP synthase are crucial for chloroplast biogenesis/development. The accuracy and reliability of RNA-Seq was verified by qRT-PCR. Moreover, the chlorophyll (Chl) a/b content, ratio of Chla/Chlb and photosynthetic rate (Pn) of YS decreased significantly. Meanwhile, chloroplasts of the YS mesophyll cells were smaller, irregular in shape, contain almost no thylakoid membrane, and even proplastid was found in YS. These findings indicate that the rpoC2 mutation down-regulated expression of the 28 cpDEGs, which disturb chloroplast biogenesis and its thylakoid membrane development. Thus, there are not enough PSI and II components to bind Chl, so that the corresponding areas of the leaf are yellow and show a low Pn. In this study, the molecular mechanism of three phenotypes of F1 (Cmvv ♀ × C. miniata ♂) was revealed, which lays a foundation for the breeding of variegated plants.

Self-healing hybrid hydrogels with sustained bioactive components release for guided bone regeneration.

Guided bone regeneration (GBR) is widely used in treating oral bone defects to exclude the influence of non-osteogenic tissue on the bone healing process. The traditional method of GBR with a titanium mesh to treat large-area bone defects is limited by the deficiency of increased trauma and costs to patients. Herein, a bi-layered scaffold for GBR composed of a fiber barrier layer and a self-healing hydrogel repair layer is successfully fabricated. The barrier layer is a fibrous membrane material with specific porosity constructed by electrospinning, while the functional layer is a self-healing hydrogel material formed by multiple dynamic covalent bonds. The system can provide an osteogenic microenvironment by preventing the infiltration of connective tissue to bone defects, maintain the stability of the osteogenic space through the self-healing property, and regulate the release of bioactive substances in the dynamic physical condition, which is beneficial to osteoblast proliferation, differentiation, and bone regeneration. This study focused on exploring the effects of different crosslinkers and bonding methods on the comprehensive properties of hydrogels. and proved that the hybrid scaffold system has good biocompatibility, cell barrier function and can enhance bone regeneration activity. Thereby it could be a promising clinical strategy for bone regeneration.

The branch-thorn occurrence of Lycium ruthenicum is associated with leaf DNA hypermethylation in response to soil water content.

BACKGROUND: Lycium ruthenicum is an eco-economic shrub which can exist in two forms, thorny and thornless under varying soil moisture conditions. The aim of this study was to determine if the two forms of L. ruthenicum were influenced by soil water content (SWC) and to test the three-way link among SWC, occurrence of branch-thorn and DNA methylation modification. METHODS AND RESULTS: Here, pot experiment was carried out to reveal the influence of SWC on the occurrence of branch-thorn and then paraffin sections, scanning electron microscope and methylation-sensitive amplification polymorphism(MSAP) analysis were used to determine the three-way link among SWC, branch-thorn occurrence and DNA methylation. The results showed that (a) soil drought promoted the development of thorn primordium into branch-thorn and (b) branch-thorn covered axillary bud to protect it against drought and other stresses; (c) the branch-thorn occurrence response to drought was correlated with hypermethylation of CCGG sites and (d) thorny and thornless plants of a clone were distinguished successfully based on the MSAP profiles of their leaves. CONCLUSIONS: Branch-thorns of the L. ruthenicum clone, which occurred in response to drought, covered axillary buds to protect them against drought and other stresses; thorn primordium of the clone did not develop into branch-thorn under the adequate soil moisture condition. The occurrence and absence of the branch-thorns were correlated with the hyper- and hypo-methylation, respectively. We proposed that the branch-thorn plasticity might be an adjustment strategy for the environment, which seems to support the theory of "Use in, waste out".

Clinical outcomes of single-step transepithelial photorefractive keratectomy and off-flap epipolis-laser in situ keratomileusis in moderate to high myopia: 12-month follow-up.

BACKGROUND: To compare the quantitative and qualitative optical outcomes of single-step transepithelial photorefractive keratectomy (TPRK) and off-flap epipolis-laser in situ keratomileusis (Epi-LASIK) in moderate to high myopia. METHODS: In this prospective self-control study, we included patients with moderate to high myopia who were randomized to undergo TPRK in one eye and Epi-LASIK in the other eye. Twelve-month follow-up results for visual acuity, refraction, ocular high-order aberrations, contrast sensitivity, postoperative pain, epithelial healing, and haze grade were assessed. RESULTS: A total of 64 eyes (32 patients) were enrolled in the study. More eyes completed re-epithelialization in the TPRK group than in the Off-flap Epi-LASIK group 3-4 days postoperatively, while all eyes completed re-epithelialization by 7 days. More eyes achieved a visual acuity (both UDVA and CDVA) of better than 20/20 in the TPRK group than in the Off-flap Epi-LASIK group. The ±0.50 D predictability for correction of the spherical equivalent (SE) was higher in the eyes of the TPRK group (91%) than in those of the off-flap Epi-LASIK group (80%) 12 months after surgery. No significant differences in ocular aberrations, including coma, spherical, and trefoil, were found between the two groups at 12 months. There were also no significant differences in visual acuity, contrast sensitivity, pain, and haze grading between the two groups. CONCLUSIONS: Both TPRK and off-flap Epi-LASIK are safe, effective, and predictable treatments for moderate to high myopia with comparable surgical outcomes. TRIAL REGISTRATION: This study was retrospectively registered on ClinicalTrial.gov ( NCT05060094 , 17/09/2021).

The effect of nerve growth factor on corneal nerve regeneration and dry eye after LASIK.

Dry eye is the most common complication after refractive surgery, especially after laser in situ keratomileusis (LASIK), in which nerves may be cut when making the corneal flap. Nerve growth factor (NGF) has been demonstrated to stimulate corneal sensitivity and nerve regeneration and NGF has been suggested as a potential treatment for dry eye disease (DED). Hence, this study aimed to investigate the effect of NGF on corneal nerve regeneration, sensitivity and dry eye symptoms after LASIK, compared to hycosan and normal saline (NS) treatments. Thirty-eight New Zealand white rabbits that underwent LASIK procedures were randomly assigned to three groups. Each group underwent NGF, hycosan, and NS treatment. The nerve densities and the number of corneal sub-basal and superficial stromal nerves were measured with confocal microscopy, and the results were compared before surgery and at one month and three months postoperatively. Corneal sensitivity was assessed with an esthesiometer. The tear breakup time (TBUT) was recorded to check for signs of dry eye. The whole corneas of the experimental animals were excised at three months after the surgery for immunohistochemically analysis. After LASIK, treatment with NGF significantly accelerated the recovery of sub-basal and superficial stromal nerve densities and the numbers, compared to hycosan and NS treatments at one month and three months postoperatively (NGF vs. hycosan, P < 0.01 each; NGF vs. NS, P < 0.01 each). The recovery of corneal sensitivity was significantly enhanced in the NGF group compared to the hycosan or NS treatment groups after surgery (P < 0.05). Also, the TBUT data showed a statistically significant longer time in the NGF group at one month, and three months postoperatively (P < 0.05). Immunofluorescence analysis showed the nerve fiber quantity of the NGF group was larger than in the hycosan and NS groups. Taken together, the experimental results suggested that mNGF had an obvious effect on promoting corneal nerve repairing and the potential to improve dry eye in different periods following LASIK.

Corneal biomechanical properties in myopic eyes evaluated via Scheimpflug imaging.

BACKGROUND: To investigate the biomechanical properties of the cornea in myopic eyes using corneal visualization Scheimpflug technology (Corvis ST). The relationships between the biomechanical properties of the cornea and the degree of myopia were also investigated. METHODS: 265 eyes of 265 subjects were included. Based on spherical equivalent (SE) in diopters (D), participants were divided into four groups: low myopia/control (SE: - 0.50 to - 3.00D), moderate myopia (SE: - 3.00 to - 6.00D), high myopia (SE: - 6.00 to - 10.00D) and severe myopia (SE greater than - 10.00D). Axial length (AL), anterior segment parameters, and corneal biomechanical properties were obtained with the Lenstar LS900, Pentacam HR and Corvis ST, respectively. RESULTS: Mean (±SD) SE was - 7.29 ± 4.31D (range: - 0.63 to - 25.75D). Mean AL was 26.31 ± 1.82 mm (range: 21.87 to 31.94 mm). Significant differences were detected within the four groups in terms of six corneal biomechanical parameters: deformation amplitude (DA), time from start until second applanation (A2-time), length of flattened cornea at the second applanation (A2-length), corneal velocity during the first and second applanation (A2-velocity), time from start to highest concavity (HC-time), and central curvature at highest concavity (HC radius). AL was positively associated with DA whereas negatively associated with A1-velocity and A2-length. SE was positively associated with A2-time, HC-time and A2-velocity, whereas negatively associated with DA. IOP was positively associated with four corneal biomechanical parameters and negatively associated with three parameters. CONCLUSIONS: Eyes with severe myopia showed greater DA, lesser A2 time, HC time, and faster A2-velocity compared to low to high myopia. This suggests the cornea becomes weaker and more deformable with elongation of axial length with corresponding increases in myopia. DA, A2-time and A2-velocity could be useful corneal biomechanical indicators in patients with myopia.

PHACOEMULSIFICATION CATARACT SURGERY WITH PROPHYLACTIC INTRAVITREAL BEVACIZUMAB FOR PATIENTS WITH COEXISTING DIABETIC RETINOPATHY: A Meta-Analysis.

PURPOSE: To evaluate the clinical effectiveness of intravitreal bevacizumab (IVB) injection combined with cataract surgery in the treatment of patients with cataract and coexisting diabetic retinopathy (DR). METHODS: Pertinent comparative studies were identified through systemic searches of PubMed, EMBASE, and the Cochrane Controlled Trials Register up to March 1, 2016. Outcome measures included corrected distance vision acuity, central macular thickness, and progression of DR and maculopathy. A meta-analysis was performed using RevMan (Cochrane Collaboration, Oxford, United Kingdom). RESULTS: Six studies describing a total of 283 eyes were identified. The meta-analysis results showed that corrected distance vision acuity measured at 1 month and 3 months after cataract surgery was significantly better in the IVB groups than in the control groups (P < 0.00001 and P = 0.01), whereas the corrected distance vision acuity at 6 months did not vary significantly between the 2 groups (P = 0.24). Similarly, the central macular thickness at 1, 3, and 6 months after surgery was significantly thinner in the IVB groups than in the control groups (P = 0.01, P = 0.0004, and P = 0.01, respectively). At 6 months, the progression of postoperative DR and maculopathy occurred more frequently in the control group than in the IVB group (P = 0.0001 and P < 0.0001, respectively). CONCLUSION: Our meta-analysis indicates that cataract surgery combined with IVB seems to be an effective treatment in patients with coexisting DR in the short term (up to 6 months). More randomized, prospective, and large-sample-sized trials are needed to evaluate the long-term effects of IVB at the time of cataract surgery in patients with DR.

Assessment of total corneal power after myopic corneal refractive surgery in Chinese eyes.

PURPOSE: To develop a new regression formula based on the Gaussian thick lens formula and to verify the accuracy of the regression formula. METHODS: In this prospective study, 207 eyes of 207 myopic subjects and 133 eyes of 67 postoperative subjects were included. For the 133 postoperative eyes, 127 eyes underwent laser-assisted in situ keratomileusis, and 6 eyes underwent photorefractive keratectomy. Subjective refraction and Pentacam HR were performed preoperatively and postoperatively, and IOLMaster was performed in the postoperative group. SimK, keratometry based on the Gaussian optic formula (KGOF), KCHM obtained using the clinical history method, and the regression formulas KRF1 and KRF2 were calculated. RESULTS: (1) A statistically significant difference (t = 155.164, P = 0.000) between SimK and KGOF of 1.24 ± 0.12 D was observed, and there was a good correlation between SimK and KGOF (r = 0.996, P = 0.000). The first regression formula (KRF1 = 0.351 + 1.021 × KGOF) was obtained using linear regression. (2) Statistically significant differences (t = 19.114, - 25.184, 4.702, and all P = 0.000) between SimK and KCHM, KGOF and KCHM and KRF1 and KCHM of 0.75 ± 0.45 D, 0.96 ± 0.44 D and 0.18 ± 0.43 D, respectively, were obtained. Good correlations between SimK and KCHM, KGOF and KCHM and KRF1 and KCHM (all r ≧ 0.977, all Ps = 0.000) were also observed. The regression formula (KRF2 = - 1.204 + 1.027 × KRF1) was obtained using linear regression. (3) Six methods were used for the prediction of IOL power in the postoperative group. The highest results were obtained from the Shammas formula (without preoperative data) combining Km (obtained by IOLMaster) followed by the KCHM and KRF2 combining Haigis formula. The third was obtained from the KCHM and KRF2 combining Hoffer Q formula; and the smallest was the Km combining Haigis formula. CONCLUSION: The IOL power predicted by KRF2 in eyes after myopic CRS may be accurate.

Protein Enables Conformation Transition of a Hydrogel Based on Pentapeptide and Boosts Immune Response in Vivo.

We report a supramolecular hydrogel based on dihistidine containing pentapeptides serving as a novel vaccine delivery system. Protein encapsulated into the hydrogel not only enhances the mechanical property up to 15-fold but also changes the conformation of the resulting nanostructure from a ß-sheet to an α-helix. The resulting hybrid hydrogel enhances antigen uptake and moderately promotes dendritic cell (DC) maturation in vitro. More importantly, the pentapeptide hydrogel promotes antigen-specific antibody production in vivo and splenocyte proliferation ex vivo.

Effects of diabetes mellitus on biomechanical properties of the rabbit cornea.

To investigate the effects of diabetes on the biomechanical behavior of cornea in alloxan-induced diabetic rabbits. Diabetes mellitus (DM) was induced in 20 rabbits using alloxan, while another 20 age- and weight-matched non-diabetic rabbits served as controls. Eyes were enucleated after 8 weeks of inducing diabetes and the whole cornea was removed with a 3 mm wide scleral ring and tested under inflation conditions with an internal pressure range of 2.0-30.0 mmHg to determine their stress-strain behavior using an inverse analysis process. The blood glucose level (BG), advanced glycosylation end products (AGEs), central corneal thickness (CCT) and intraocular pressure (IOP) increased significantly in the DM group. There were statistically significant correlations between BG and AGEs (r = 0.768, p = 0.00), and between AGEs and CCT variation upon induction of DM (r = 0.594, p = 0.00). The tangent modulus (Et) of the cornea at four stress levels (1-4 kPa, equivalent to approximately IOP of 7.5, 15, 22.5 and 30 mmHg, respectively) was significantly higher in diabetic rabbits than in the control group (p < 0.05). Further, Et at stress of 2 kPa (which corresponded to the average IOP for the control group) was significantly correlated with BG (r = 0.378, p < 0.05), AGEs (r = 0.496, p < 0.05) and CCT variation upon induction of DM (r = 0.439, p < 0.05). IOP, as measured by contact tonometry, was also significantly correlated with both CCT (r = 0.315, p < 0.05) and Et at 2 kPa (r = 0.329, p < 0.05), and even after correcting for the effects of CCT and Et, IOP still significantly increased with both AGEs (r = 0.772, p = 0.00) and BG (r = 0.762, p = 0.00). The cornea of diabetic rabbits showed a significant increase in mechanical stiffness as evidenced by increases in corneal thickness and tangent modulus. The Et increase may be explained by a non-enzymatic cross-linking of collagen fibrils mediated by AGEs due to the high blood glucose levels in diabetes. The study also found significant IOP increases with higher blood glucose level even after controlling the effects of both corneal thickness and tangent modulus.

Application of case teaching in genetics courses to students majoring in forestry.

Undergraduate students majoring in forestry generally reflect that genetics is one of the most difficult compul-sory courses, because the traditional teaching method is difficult to satisfy their needs. According to the theoretical charac-teristics of forestry and actual demands of the students, in the light of teaching and research experience in recent years, we adopted a series of typical genetic cases such as 'opening coffin to identify relatives', stem-throne of Lycium ruthenicum Murr, and magic powers in Harry Potter. Our practices revealed that the case teaching in genetics could train good personality traits, learning abilities and creativity of the students, stimulate their interests and initiatives in learning, and increase systematic learning.

Deferoxamine inhibits microglial activation, attenuates blood-brain barrier disruption, rescues dendritic damage, and improves spatial memory in a mouse model of microhemorrhages.

Cerebral microbleeds are strongly linked to cognitive dysfunction in the elderly. Iron accumulation plays an important role in the pathogenesis of intracranial hemorrhage. Deferoxamine (DFX), a metal chelator, removes iron overload and protects against brain damage in intracranial hemorrhage. In this study, the protective effects of DFX against microhemorrhage were examined in mice. C57BL6 and Thy-1 green fluorescent protein transgenic mice were subjected to perforating artery microhemorrhages on the right posterior parietal cortex using two-photon laser irradiation. DFX (100 mg/kg) was administered 6 h after microhemorrhage induction, followed by every 12 h for three consecutive days. The water maze task was conducted 7 days after induction of microhemorrhages, followed by measurement of blood-brain barrier permeability, iron deposition, microglial activation, and dendritic damage. Laser-induced multiple microbleeds in the right parietal cortex clearly led to spatial memory disruption, iron deposits, microglial activation, and dendritic damage, which were significantly attenuated by DFX, supporting the targeting of iron overload as a therapeutic option and the significant potential of DFX in microhemorrhage treatment. Irons accumulation after intracranial hemorrhage induced a serious secondary damage to the brain. We proposed that irons accumulation after parietal microhemorrhages impaired spatial cognition. After parietal multiple microhemorrhages, increased irons and ferritin contents induced blood-brain barrier disruption, microglial activation, and further induced dendrites loss, eventually impaired the water maze, deferoxamine treatment protected from these damages.

Efficacy Comparison of 16 Interventions for Myopia Control in Children: A Network Meta-analysis.

PURPOSE: To determine the effectiveness of different interventions to slow down the progression of myopia in children. METHODS: We searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov from inception to August 2014. We selected randomized controlled trials (RCTs) involving interventions for controlling the progression of myopia in children with a treatment duration of at least 1 year for analysis. MAIN OUTCOME MEASURES: The primary outcomes were mean annual change in refraction (diopters/year) and mean annual change in axial length (millimeters/year). RESULTS: Thirty RCTs (involving 5422 eyes) were identified. Network meta-analysis showed that in comparison with placebo or single vision spectacle lenses, high-dose atropine (refraction change: 0.68 [0.52-0.84]; axial length change: -0.21 [-0.28 to -0.16]), moderate-dose atropine (refraction change: 0.53 [0.28-0.77]; axial length change: -0.21 [-0.32 to -0.12]), and low-dose atropine (refraction change: 0.53 [0.21-0.85]; axial length change: -0.15 [-0.25 to -0.05]) markedly slowed myopia progression. Pirenzepine (refraction change: 0.29 [0.05-0.52]; axial length change: -0.09 [-0.17 to -0.01]), orthokeratology (axial length change: -0.15 [-0.22 to -0.08]), and peripheral defocus modifying contact lenses (axial length change: -0.11 [-0.20 to -0.03]) showed moderate effects. Progressive addition spectacle lenses (refraction change: 0.14 [0.02-0.26]; axial length change: -0.04 [-0.09 to -0.01]) showed slight effects. CONCLUSIONS: This network analysis indicates that a range of interventions can significantly reduce myopia progression when compared with single vision spectacle lenses or placebo. In terms of refraction, atropine, pirenzepine, and progressive addition spectacle lenses were effective. In terms of axial length, atropine, orthokeratology, peripheral defocus modifying contact lenses, pirenzepine, and progressive addition spectacle lenses were effective. The most effective interventions were pharmacologic, that is, muscarinic antagonists such as atropine and pirenzepine. Certain specially designed contact lenses, including orthokeratology and peripheral defocus modifying contact lenses, had moderate effects, whereas specially designed spectacle lenses showed minimal effect.

Leaf patterning of Clivia miniata var. variegata is associated with differential DNA methylation.

KEY MESSAGE: Leaf patterns (yellow, green and striped) of Clivia miniata var. variegata might be caused by differential DNA methylation in CCGG sites in response to heterogeneous environmental pressure. Clivia miniata is an important ornamental plant.Clivia miniata var. variegata (Cmvv) is a variegated leaf mutant of C. miniata. Typical Cmvv has attractive green and yellow-stripped leaves. The study has revealed that an explant of Cmvv, even a full-green explant, could regenerate plants of three different types: yellow, green, ands triped; normal-appearing chloroplasts were found in guard cells but not in mesophyll cells of all the three types of Cmvv using confocal laser scanning microscopy (CLSM).Thus, we speculated that cells of the three types of Cmvv had an identical mutation and the mutation might disturb mesophyll cell chloroplast biogenesis after symplastic isolation of guard cells. Using CLSM and methylation sensitive amplification polymorphism (MSAP), we found that (a) striped leaves of Cmvv are due to sectorial decreases in chlorophyll levels and the decreases are associated with CG hypermethylation; (b) extent of epigenetic divergence among the three types of Cmvv leaves is positively correlated with intensity of leaf-color difference; and (c) green stripes of two plants are clustered in one group based on the MSAP profiles, but green and yellow stripes of a plant are not. Sequencing analysis indicated that CG hypermethylation in gene bodies of CPSAR1 and ycf2 might lead to gene silencing and yellow leaves/stripes of Cmvv. All together, it is possible that cytosine methylation involved regulating leaf color of Cmvv, also striped pattern of Cmvv might be caused by differential DNA methylation in response to heterogeneous environmental pressure. Furthermore, a novel leaf-color epigenetic hypothesis was proposed in this article.

Neovascular glaucoma: a retrospective review from a tertiary center in China.

BACKGROUND: The purpose of this study is to report the prevalence, etiology, treatment and outcomes of neovascular glaucoma (NVG) in a tertiary care ophthalmic center in China. METHODS: Medical records of patients diagnosed as NVG at the Wenzhou Medical University between 2003 and 2014 were reviewed. Success was defined as IOP between 6 and 21 mmHg without topical or systemic glaucoma medications with retention of presenting visual acuity (VA). RESULTS: NVG was diagnosed in 483 of 8306 (5.8%) of all glaucoma patients. Etiology is reported for all 310 eyes of 284 patients managed in the department. Interventions depended on insurance as well as personal finances; outcomes are reported for the 149 eyes of 138 patients with complete data that met follow up requirements. Diabetic retinopathy (DR,39.7%) was the major cause of NVG. Kaplan Meier survival analysis showed a success rate of 84.8% at 1 year, 47.5% at 3 years and 21.9% at 5 years. Major interventions included glaucoma drainage device (GDD) in 103 eyes and trans-scleral cyclophotocoagulation (TSCPC) in 22 eyes. Complications were more common in the GDD group. CONCLUSIONS: NVG comprised 5.8% of glaucoma patients seen in a tertiary Chinese hospital. DR was identified as the commonest cause and probably reflects the increasing prevalence of diabetes in China. Surgical interventions were partly determined by insurance status and personal finances. GDD was the commonest surgical intervention used and also had the most complications.

Effects of Long-term Soft Contact Lenses on Tear Menisci and Corneal Nerve Density.

PURPOSE: We investigated the relationship between tear menisci and corneal subbasal nerve density (SND) in long-term soft contact lens (CL) wearers. METHODS: Three groups were enrolled for this study: asymptomatic non-CL controls (N-CL group), asymptomatic soft CL wearers (A-CL group), and symptomatic soft CL wearers with self-reported moderate to severe dryness (S-CL group). Upper and lower tear menisci height (UTMH, LTMH) and area (UTMA, LTMA) were measured by optical coherence tomography. This was followed by measurements of fluorescein tear breakup time, fluorescein staining, and the Schirmer I test. In vivo confocal microscopy measured the SND in the nasal, central, and temporal regions of the cornea. RESULTS: The UTMH, UTMA, LTMH, and LTMA were significantly lower in the S-CL group compared with the N-CL group (P<0.05). The combined corneal SND of the temporal and nasal regions of the S-CL group was lower than for the N-CL group (P<0.05). The LTMH was correlated with the SND of the temporal (r=0.410), nasal (r=0.423), combined temporal and nasal (r=0.516), and combined temporal, nasal, and central regions (r=0.430, all P<0.01). The LTMA was also correlated with the SND of the temporal (r=0.379), nasal (r=0.292), combined temporal and nasal (r=0.422), and combined temporal, nasal, and central regions (r=0.367, all P<0.05). The temporal and nasal corneal SNDs were more strongly correlated with the LTMH and LTMA than with the UTMH and UTMA. CONCLUSIONS: Soft CL wearers with dry eye symptoms have reduced tear menisci. The alteration of midperipheral corneal SND may contribute to dry eye symptoms.

[Objective assessment of comprehensive optical quality among adults at different ages].

OBJECTIVE: To objectively assess and compare comprehensive optical quality among adults at different ages. METHODS: In this cross-sectional study, there were 432 subjects (432 eyes) aged from 20 to 70 years with best corrected visual acuity (BCVA) better than 4.9. If both eyes of a subject had equal BCVA, one eye was selected randomly. Otherwise, the eye with better BCVA was chosen. The patients were divided into 5 groups at an age interval of 10 years. The optical quality analysis system Ⅱ (OQASⅡ) was used to measure the following optical quality parameters: the modulation transfer function cutoff frequency (MTFcutoff), the Strehl ratio, three OQAS values (OV100%, OV20%, and OV9%), and the objective scatter index (OSI). Each optical quality parameter was compared among different groups by One-way ANOVA. RESULTS: In the groups of 20-29 years, 30-39 years, 40-49 years, 50-59 years, and 60-69 years, the MTFcutoff was (43.91±7.43), (40.93±9.92), (37.16±9.04), (36.69±7.87), and (28.52±8.31) cpd, respectively; the Strehl ratio was 0.26±0.06, 0.24±0.06, 0.20±0.05, 0.20±0.04, and 0.16±0.04, respectively; the OV100% was 1.47±0.24, 1.36±0.33, 1.24±0.30, 1.22±0.26, and 0.96±0.28, respectively; the OV20% was 1.51±0.33, 1.40±0.38, 1.22±0.36, 1.20±0.28, and 0.91±0.32, respectively; the OV9% was 1.14±0.26, 1.41±0.40, 1.20± 0.37, 1.18±0.28, and 0.89±0.28, respectively; the OSI was 0.42±0.24, 0.53±0.32, 0.54±0.34, 0.54±0.26, and 1.06±0.56, respectively. There were significant differences in the mean values of MTFcutoff, Strehl ratio, OV100%, and OV20% among groups (P<0.05), except for the groups of 40-49 years and 50-59 years (P>0.05). The OV9% was significantly different among groups (P<0.05), except for the groups of 20-29 years, 40-49 years, and 50-59 years (P>0.19). The OSI was also significantly different among groups (P<0.05), except for the groups of 30-39 years, 40-49 years, and 50-59 years (P>0.70). CONCLUSION: The comprehensive optical quality in the young healthy population is better than the old, except for a plateau in the middle-aged population.

[The correlations between corneal sensation, tear meniscus volume, and tear film osmolarity after femtosecond laser-assisted LASIK].

OBJECTIVE: To investigate the correlations between corneal sensation, tear meniscus volume, and tear film osmolarity after femtosecond laser-assisted LASIK (FS-LASIK) surgery. METHODS: In this prospective clinical study, 31 patients undergoing FS-LASIK for myopia were recruited. The upper and lower tear meniscus volumes (UTMV and LTMV) were measured by customized anterior segment optical coherence tomography, tear film osmolarity was measured by a TearLab Osmolarity test device, central corneal sensation was measured by a Cochet-Bonner esthesiometer preoperatively, at 1 week, 1 and 3 months postoperatively. Repeated measures analysis of variance was used to evaluate whether the tear film osmolarity, tear meniscus volume, and corneal sensation were changed after surgery. The correlations between these variables were analyzed by the Pearson correlation analysis. RESULTS: The tear film osmolarity was (310.03 ± 16.48) mOsms/L preoperatively, (323.51 ± 15.92) mOsms/L at 1 week, (319.93 ± 14.27) mOsms/L at 1 month, and (314.97±12.91) mOsms/L at 3 months. The UTMV was (0.42±0.15), (0.25± 0.09), (0.30±0.11), and (0.35±0.09) µL, respectively; the LTMV was (0.60±0.21),(0.37±0.08), (0.44± 0.14), and (0.52±0.17) µL, respectively. The tear film osmolarity was significantly higher at 1 week and 1 month postoperatively compared with the baseline (P=0.001, 0.004), and reduced to the preoperative level at 3 months (P=0.573). The UTMV, LTMV, and corneal sensation values presented significant decreases at all postoperative time points (all P<0.05). The Pearson correlation analysis showed the postoperative UTMV had a weak relationship with corneal sensation at 1 week after surgery (r=0.356,P=0.005). There were significant correlations between the preoperative LTMV and corneal sensation at 1 week, 1 and 3 months (respectively, r=0.422, 0.366, 0.352;P=0.001, 0.004, 0.006). No significant correlations were found between the tear film osmolarity, tear meniscus volume, and corneal sensation after surgery (all P>0.05). CONCLUSION: The tear film osmolarity, tear meniscus volume, and corneal sensation became aggravated due to the FS-LASIK surgery procedures. There were significant correlations between the preoperative tear meniscus volume and recovery of corneal sensation early after surgery. A higher tear meniscus volume before surgery may contribute to a faster corneal sensation recovery.

Comparison of the short-term and long-term outcomes of laparoscopic hysterectomies and of abdominal hysterectomies: a case study of 4,895 patients in the Guangxi Zhuang Autonomous Region, China.

BACKGROUND: To evaluate the short-term and long-term outcomes after laparoscopic hysterectomy (LH) compared with abdominal hysterectomy (AH) in case of benign gynecological disease. METHODS: A multi-center cohort retrospective comparative study of population among 4,895 hysterectomies (3,539 LH vs.1,356 AH) between 2007 and 2013 was involved. Operative time (OT), estimated blood loss (EBL), intra-operative and post-operative complications, passing flatus; days with indwelling catheter, questionnaires covering pelvic floor functions and sexual functions were assessed. RESULTS: The EBL (174.1±157.4 vs. 263.1±183.2 cc, LH and AH groups, respectively), passing flatus (38.7±14.1 vs. 48.1±13.2 hours), days with indwelling catheter (1.5±0.6 vs. 2.2±0.8 days), use of analgesics (6.5% vs. 73.1%), intra-operative complication rate (2.4% vs. 4.1%), post-operative complication rate (2.3% vs. 5.7%), post-operative constipation (12.1% vs. 24.6%), mild and serious stress urinary incontinence (SUI) post-operative (P<0.001; P=0.014), and proportion of Female Sexual Functioning Index (FSFI) total score <26.55 post-operative (P<0.001) of the LH group were significantly less than those of AH group. There were no significant differences in OT (106.5±34.5 vs. 106.2±40.3 min) between the two groups. CONCLUSIONS: LH is a safe and efficient operation for improving patients?long-term quality of life (QoL), and LH is a cost-effectiveness procedure for treating benign gynecological disease. LH is superior to AH due to reduced EBL, reduced post-operative pain and earlier passing flatus.

[Study of Blood Oxygen Measuring Method Based on Multiple Regression Analysis].

In the traditional measurement of blood oxygen, amended Lambert-Beer Law is used to calculate the oxygen percentage in the blood. On the one hand, results will be acquired slowly because of the divide operation. On the other hand, amount of precision will be lost because of the error by using ratio, wich leads to the low accuracy results. In order to solve this problem, multiple regression analysis is used in this paper to measure and evaluate the oxygen percentage in the blood. Results show that, compared to the ratio, the new method has an obvious advantage and can be realized by hardware more easily.