Molecular characterization of cefepime and aztreonam nonsusceptibility in Haemophilus influenzae.

BACKGROUND: Cefepime and aztreonam are highly efficacious against H. influenzae, and resistant strains are rare. In this study, we isolated cefepime- and aztreonam-nonsusceptible H. influenzae strains and addressed the molecular basis of their resistance to cefepime and aztreonam. METHODS: Two hundred and 28 specimens containing H. influenzae were screened, of which 32 isolates were enrolled and applied to antimicrobial susceptibility testing and whole-genome sequencing. Genetic variations that were detected in all nonsusceptible isolates with statistical significance by Fisher's exact tests were identified as cefepime or aztreonam nonsusceptibility related. Functional complementation assays were conducted to assess the in vitro effects of proteins with sequence substitutions on drug susceptibility. RESULTS: Three H. influenzae isolates were nonsusceptible to cefepime, one of which was also nonsusceptible to aztreonam. Genes encoding TEM, SHV and CTX-M extended-spectrum ß-lactamases were not detected in the cefepime- and aztreonam-nonsusceptible isolates. Five genetic variations in four genes and 10 genetic variations in five genes were associated with cefepime and aztreonam nonsusceptibility, respectively. Phylogenetic analyses revealed that changes in FtsI were correlated strongly with the MIC of cefepime and moderately with aztreonam. FtsI Thr532Ser-Tyr557His cosubstitution linked to cefepime nonsusceptibility and Asn305Lys-Ser385Asn-Glu416Asp cosubstitution to aztreonam nonsusceptibility. Functional complementation assays revealed that these cosubstitutions increased MICs of cefepime and aztreonam in susceptible H. influenzae isolates, respectively. CONCLUSIONS: Genetic variations relevant to resistant phenotypes of cefepime and aztreonam nonsusceptibility in H. influenzae were identified. Moreover, the effects of FtsI cosubstitutions on increasing MICs of cefepime and aztreonam in H. influenzae were demonstrated.

Hydration Energy-Dependent Ion Intercalation on Graphite and the Asymmetric Electrowetting.

Ion intercalation in graphite is widely used in desalination, batteries, and graphene stripping; it has high value in the fields of industry and research. However, selective ion transport, particularly (de)hydration energy and the hydration shell effect on the intercalation of ions into the graphite interlayer spaces, is still unclear. Here, we report low-voltage ion intercalation as observed by electrowetting on highly oriented pyrolytic graphite of an aqueous drop containing various inorganic salts. The electrowetting response exhibits asymmetric behavior with no contact angle change for the negative polarity and a threshold voltage for the onset of the contact angle change for the positive polarity. To explain the asymmetric electrowetting behavior and quantitatively predict the threshold voltage, we developed a physical model based on the hydration shell energy and size of the ion that undergoes partial breaking/deformation during the co-intercalation into the spaces between graphite layers. Electrowetting experiments using ions with various hydration energies and hydration radii were performed to confirm the prediction of the model. Further, we show a strategy to make the electrowetting response of LiCl drops symmetric via tuning the hydration energy of the Li+ ions using a binary solvent of a glycerol-water mixture. This article will provide an understanding of the hydration (solvation) energy dependence intercalation mechanism in graphite for electrowetting, which underpins various processes such as ion battery applications and the graphene exfoliation process.

Removal of methylisothiazolinone biocide from wastewater by VUV/UV advanced oxidation process: Kinetics, mechanisms and toxicity.

Methylisothiazolinone (MIT) is frequently used as antimicrobial in household and industrial products, and poses ecological and health risks to aquatic organisms and humans. In this study, vacuum ultraviolet (VUV)/ultraviolet (UV) irradiation was found highly efficient for removal of MIT. The rate constant of MIT degradation (kobs) under VUV/UV irradiation was 3.75 µEinstein-1 cm2, which was around 12.5 times higher than that under UV irradiation. The •OH concentration during the VUV/UV process was 1.0 × 10-12 M. The contributions of UV photolysis and •OH oxidation to MIT degradation under VUV/UV irradiation were 7.3% and 92.7%, respectively. The optimum solution pH (6.0-7.1) gave kobs 33%-39% higher than those at pH 3.9 and 9.3. CO32-/HCO3- inhibited MIT degradation and the kobs decreased by 74% when the concentration of CO32-/HCO3- was increased to 1 mM. The order of MIT removal efficiency under VUV/UV irradiation was ultrapure water > secondary effluent > reverse osmosis (RO) concentrate, because of the light screening and •OH quenching effect of actual wastewater. In RO concentrate, the rate constant of MIT degradation under VUV/UV irradiation was 22% higher than that obtained under UV irradiation. The reduction of TOC, UV254, and total fluorescence regional integration of the RO concentrate during VUV/UV process were 7.2%, 34.9%, and 52.3%, respectively. Twelve main transformation products of MIT were identified after VUV/UV degradation. The main degradation mechanisms of MIT were sulfur atom oxidation and hydroxyl addition. Quantitative structure-activity relationship analysis showed that VUV/UV degradation was an efficient method to remove the toxicity of MIT.

Protective role of exosomes derived from regulatory T cells against inflammation and apoptosis of BV-2 microglia under oxygen-glucose deprivation/reperfusion challenge.

Regulatory T cells (Tregs) are found to participate in the pathogenesis of cerebral ischemic stroke. Exosomes derived from Tregs (Treg-Exos) were found to mediate the mechanism of Tregs' roles under various physiological and pathological conditions. But the roles of Treg-Exos in cerebral ischemic stroke are still unclear. Here, we explored the protective effects of Treg-Exos against microglial injury in response to oxygen-glucose deprivation/reperfusion (OGD/R) exposure. The results showed that Tregs-Exos relieved OGD/R-caused increases in LDH release and caspase-3 activity in BV-2 cells. The decreased cell viability and increased percentage of TUNEL-positive cells in OGD/R-exposed BV-2 cells were attenuated by Tregs-Exos treatment. Tregs-Exos also suppressed OGD/R-induced increase in production of tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and IL-6 in BV-2 microglia. Furthermore, Tregs-Exos induced the expression levels of phosphorylated phosphatidylinositol-3-kinase (p-PI3K) and phosphorylated protein kinase B (p-Akt) in BV-2 microglia under the challenge of OGD/R. Inhibition of the PI3K/Akt signaling by LY294002 partly reversed the effects of Tregs-Exos on cell apoptosis and inflammation in OGD/R-exposed BV-2 microglia. These results indicated that Tregs-Exos exerted protective effects against the OGD/R-caused injury of BV-2 microglia by activating the PI3K/Akt signaling.

Partial Stapled Hemorrhoidopexy Versus Circumferential Stapled Hemorrhoidopexy for Grade III to IV Prolapsing Hemorrhoids: A Randomized, Noninferiority Trial.

BACKGROUND: Long-term outcomes and efficacy of partial stapled hemorrhoidopexy are not known. OBJECTIVE: The purpose of this study was to compare the long-term clinical efficacy and safety of partial stapled hemorrhoidopexy with circumferential stapled hemorrhoidopexy. DESIGN: This was a parallel group, randomized, noninferiority clinical trial. SETTINGS: The study was conducted at a single academic center. PATIENTS: Patients with grade III/IV hemorrhoids between August 2011 and November 2013 were included. INTERVENTIONS: Three hundred patients were randomly assigned to undergo either partial stapled hemorrhoidopexy (group 1, n = 150) or circumferential stapled hemorrhoidopexy (group 2, n = 150). MAIN OUTCOME MEASURES: The primary outcome was the rate of recurrent prolapse at a median follow-up period of 5 years with a predefined noninferiority margin of 3.75%. Secondary outcomes included incidence and severity of postoperative pain, fecal urgency, anal continence, and the frequency of specific complications, including anorectal stenosis and rectovaginal fistula. RESULTS: The visual analog scores in group 1 were less than those in group 2 (p < 0.001). Fewer patients in group 1 experienced postoperative urgency compared with those in group 2 (p = 0.001). Anal continence significantly worsened after both procedures, but the difference between preoperative and postoperative continence scores was higher for group 2 than for group 1. Postoperative rectal stenosis did not develop in patients in group 1, although it occurred in 8 patients (5%) in group 2 (p = 0.004). The 5-year cumulative recurrence rate between group 1 (9% (95% CI, 4%-13%)) and group 2 (12% (95% CI, 7%-17%)) did not differ significantly (p = 0.137), and the difference was within the noninferiority margin (absolute difference, -3.33% (95% CI, -10.00% to 3.55%)). LIMITATIONS: The study was limited because it was a single-center trial. CONCLUSIONS: Partial stapled hemorrhoidopexy is noninferior to circumferential stapled hemorrhoidopexy for patients with grade III to IV hemorrhoids at a median follow-up period of 5 years. However, partial stapled hemorrhoidopexy was associated with reduced postoperative pain and urgency, better postoperative anal continence, and minimal risk of rectal stenosis. See Video Abstract at http://links.lww.com/DCR/A790.Trial registration (chictr.org) identifier is chiCTR-trc-11001506.

Transition of interfacial capacitors in electrowetting on a graphite surface by ion intercalation.

The low voltage electrowetting response of a LiCl aqueous solution on a freshly cleaved surface of highly oriented pyrolytic graphite (HOPG) is presented. For applied voltages below 1 V, the energy stored in the electrical double layer (EDL) is insufficient to drive the spreading of the drop due to the pinning of the three phase contact line at the step edges. Electrochemical impedance spectroscopy shows a dramatic increase in capacitance above 1 V, which provides a sufficient electrowetting force for depinning the contact line, resulting in a subsequent decrease of the contact angle. The transition of the interfacial capacitance from the EDL to the many-fold high capacitance of the pseudocapacitor drives the electrowetting transition on the HOPG surface. The observed changes in the capacitances above 1 V are correlated with the cyclic voltammetry and atomic force microscopy results, which show that the Cl- ions intercalate into the graphite galleries upon acquiring sufficient energy to overcome the van der Waals attraction between the graphene layers through the side of the step edge of the basal planes. To the best of our knowledge, this is the first study on the voltage dependent intercalation mediated transition of interfacial capacitance driving the spreading of an aqueous electrolyte drop on the HOPG surface, which provides a fundamental understanding of the mechanism and opens up potential applications in microfluidics and charge storage technologies.

[The Effect of Disordered Glycometabolism of Kashin-Beck Disease on the Function of Chondrocytes].

OBJECTIVE: To reveal the effect of disordered glycometabolism in Kashin-Beck disease (KBD) chondrocytes,we compared changes in expressions of extracellular matrix components (collagen and aggrecan),apoptosis and oxidative stress under the condition of different concentrations of glucose. METHODS: The damage of KBD chondrocytes and normal chondrocytes under high glucose culture was measured in compared with cells under normal culture,that included the changes of proliferation and morphology; the concentrations of glucose in culture medium during the process of chondrocytes culture; the expressions of type Ⅱ collagen and aggrecan detected by quantitative real-time polymerase chain reaction (qRT-PCR) and Toluidine blue staining; cell apoptosis and reactive oxygen species (ROS) content detected by flow cytometry and fluorescence staining. RESULTS: The growth and proliferation of KBD chondrocytes were inferior to normal chondrocytes. The glucose uptake of KBD chondrocytes and normal chondrocytes under high glucose culture were basically the same (P>0.05). Disordered glycometabolism caused by high glucose decreased the expression of type Ⅱ collagen and aggrecan in KBD chondrocytes (P<0.05),meanwhile,increased apoptosis and cellular ROS generation of cultured chondrocytes (P<0.05). CONCLUSION: The disordered glycometabolism can affect the function of KBD chondrocytes through reducing the expression of type Ⅱ collagen and aggrecan and increasing the apoptosis and the oxidative stress.

Deformation of confined liquid interfaces by inhomogeneous electric fields and localized particle forces.

HYPOTHESIS: Oil-water interfaces that are created by confining a certain amount of oil in a square shaped pixel (∼200 x 200 µm2 with a height of ∼10 µm) topped by a layer of water, have a curvature that depends on the amount of oil that happens to be present in the confining area. Under the application of an electric field normal to the interface, the interface will deform due to inhomogeneities in the electric field. These inhomogeneities are expected to arise from the initial curvature of the meniscus, from fringe fields that emerge at the confining pixel walls and, if applicable, from interfacially adsorbed particles. MODELING AND EXPERIMENTS: We model the shape of the confined oil-water interface invoking capillarity and electrostatics. Furthermore, we measure the initial curvature by tracking the position of interfacially adsorbed particles depending on sample tilt. FINDINGS: We found that the pixels exhibited meniscus curvature radii ranging from 0.6-7 mm. The corresponding model based minimum oil film thicknesses range between 0.7 and 9 µm. Furthermore, the model shows that the initial meniscus curvature can increase up to 76 percent relative to the initial curvature by the electric field before the oil film becomes unstable. The pixel wall and particles are shown to have minimal impact on the interface deformation.

Spatially confined CuFe2O4 nanosphere in N/O-codoped porous carbon mimetics for triple-mode sensing of antibiotics and visual detection of neurotransmitters in biofluids.

BACKGROUND: Carbon-based nanozymes have recently received enormous concern, however, there is still a huge challenge for inexpensive and large-scale synthesis of magnetic carbon-based "Two-in-One" mimics with both peroxidase (POD)-like and laccase-like activities, especially their potential applications in multi-mode sensing of antibiotics and neurotransmitters in biofluids. Although some progresses have been made in this field, the feasibility of biomass-derived carbon materials with both POD-like and laccase-like activities by polyatomic doping strategy is still unclear. In addition, multi-mode sensing platform can provide a more reliable result because of the self-validation, self-correction and mutual agreement. Nevertheless, the use of magnetic carbon-based nanozyme sensors for the multi-mode detection of antibiotics and neurotransmitters have not been investigated. RESULTS: We herein report a shrimp shell-derived N, O-codoped porous carbon confined magnetic CuFe2O4 nanosphere with outstanding laccase-like and POD-like activities for triple-mode sensing of antibiotic d-penicillamine (D-PA) and chloramphenicol (CPL), as well as colorimetric detection of neurotransmitters in biofluids. The magnetic CuFe2O4/N, O-codoped porous carbon (MCNPC) armored mimetics was successfully fabricated using a combined in-situ coordination and high-temperature crystallization method. The synthesized MCNPC composite with superior POD-like activity can be used for colorimetric/temperature/smartphone-based triple-mode detection of D-PA and CPL in goat serum. Importantly, the MCNPC nanozyme can also be used for colorimetric analysis of dopamine and epinephrine in human urine. SIGNIFICANCE: This work not only offered a novel strategy to large-scale, cheap synthesize magnetic carbon-based "Two-in-One" armored mimetics, but also established the highly sensitive and selective platforms for triple-mode monitoring D-PA and CPL, as well as colorimetric analysis of neurotransmitters in biofluids without any tanglesome sample pretreatment.

Robust reverse-electrowetting based energy harvesting on slippery surface.

Reversed-electrowetting based droplet electricity generator (REWOD-DEG) shows merits in high power densities, tunable output formats, and wide adaptability to diverse mechanical energies. However, the surface charge trapping and dielectric failure, which are also common challenges for electrowetting system, hinders the development of reliable REWOD-DEGs for long-term running. We innovatively introduce a slippery lubricant-infused porous surface (SLIPS) into REWOD-DEG. Benefits from the significant inhibitory effect for surface charge trapping and ambient contamination, self-healing characteristic given by SLIPS, and robust reversed-electrowetting based energy harvesting were achieved. The SLIPS enhanced REWOD-DEG experienced 100 days of intermittent energy harvesting without deterioration. In addition, the device shows robust performances when exposed to a variety of extreme working conditions, like low temperature, pH, humidity, fouling, and even scratching. This work may address the core application challenges of REWOD based devices, and inspire the development of other robust droplet-based electricity generators.

Degradation of chloromethylisothiazolinone antimicrobial by Vacuum-Ultraviolet/Ultraviolet irradiation: Reactive species, degradation pathway and toxicity evaluation.

Chloromethylisothiazolinone (CMIT) has been extensively used as antimicrobial in cosmetics, detergents, wall paints, and anti-fouling products. To prevent the potential ecological and health risks, the degradation mechanisms and toxicity changes of CMIT by Vacuum-Ultraviolet/Ultraviolet (VUV/UV) irradiation were investigated in this study. VUV/UV irradiation showed better performance on CMIT degradation compared to sole UV photolysis. The removal efficiency of CMIT with photon fluence of 0.6 µEinstein/cm2 was 8% and 100% by UV or VUV/UV irradiation, respectively. Radical quenching experiments indicated that 254 nm photolysis, 185 nm photolysis, and •OH oxidation contributed to CMIT degradation during VUV/UV process, with fluence-based apparent rate constants of 0.16, 0.13, and 4.9 µEinstein-1cm2, respectively. The formation of H2O2 during VUV/UV process increased to 0.7 mg/L at 4.5 min, and the concentration of •OH ranged within 1.0-3.8 × 10-12 M. The degradation of CMIT by VUV/UV irradiation in neutral condition was slightly higher than that in acidic and basic conditions. The removal efficiency of CMIT with reaction time of 2 min decreased from 92.2% to 34.3% when the concentration of HCO3-/CO32- increased to 1 mM. The degradation of CMIT by VUV/UV irradiation in secondary effluents was lower than that in ultrapure water because of the •OH scavenging effects, but still 2.9 times higher than that by UV photolysis. Four main degradation mechanisms of CMIT were observed during VUV/UV process, including the oxidation of sulfur, addition of hydroxyl groups on the double-carbon-bond, demethylation on the nitrogen, and substitution of organochlorine atom by hydroxyl group. Based on the quantitative structure activity relationship analysis, most products of CMIT underwent complete detoxification to fish and daphnia. 40% of products still showed acute toxicity to algae, but most of them were less toxic than CMIT.

Concentrations and Related Health Risk Assessment of Pesticides, Phthalates, and Heavy Metals in Strawberries from Shanghai, China.

ABSTRACT: In the present study, a risk assessment of pesticides, phthalates, and heavy metals in strawberries (n = 335) in recent years was conducted by determining the estimated daily intake, target hazard quotient, and hazard index. The study used 128 pesticides, 18 phthalates, and three heavy metals in this determination. It detected 51 pesticide residues in the strawberry samples, and 97.91% samples had levels of at least 1 of the 51 pesticides above the limit of detection. In addition, 2.39% of samples had pesticides higher than the Chinese maximum residue limit. Multiple pesticide residues were detected in most samples. Bis-2-ethylhexyl phthalate, diisobutyl phthalate, and dibutyl phthalate were detected in the strawberry samples, with a high frequency of detection. Their detectable rates were 100, 100, and 89.9%, respectively. In most samples, lead, cadmium, and nickel were detected, with detectable rates 75.76, 92.93, and 92.93%, respectively. The estimated daily intake of analyzed pesticide, phthalate, and heavy metal residues appears to be relatively low compared with the acceptable daily intake. The average target hazard quotients and hazard indices were less than 1. That means that customers who are exposed to the average contaminant levels may not pose a significant health risk. Our results show that the strawberries may be polluted by many kinds of contaminants. Therefore, monitoring of pesticide, phthalate, and heavy metal residues in strawberries should be increasingly developed to fully protect the health of the consumer.

Protective Effects of Shrimp Peptide on Dextran Sulfate Sodium-Induced Colitis in Mice.

Inflammatory bowel disease, an intestinal relapsing inflammatory disease, not only impairs gastrointestinal function but also increases the chances of developing colon cancer. Currently, the effects of shrimp peptide (SP) in mice model of ulcerative colitis (UC) are still unclear. In particular, it is uncertain whether SP affects the gut flora with UC mice. In this study, we investigated the anti-inflammatory effects of SP on a dextran sulfate sodium (DSS)-induced mouse model of UC. Firstly, the molecular weight of SP was mainly distributed in the range of 180-1,000 Da (61.95% proportion), and the amino acid composition showed that SP contained 17 amino acids, of which, the essential amino acids accounted for 54.50%. In vivo, oral SP significantly attenuated the severity of colitis, such as diarrhea, weight loss, and rectal bleeding. Furthermore, treatment with SP remarkably ameliorated intestinal barrier integrity, thus lowering the levels of the inflammatory cytokines and ameliorating antioxidant indices and intestinal injury indicators in the serum and colon. Lastly, the cecal contents were used to sequence and analyze the 16S rRNA genes of bacteria. Results suggested that treatment with SP could restore the balance of intestinal flora in modeled mice by regulating the abundance of pathogenic and beneficial bacteria. Furthermore, SP could significantly improve intestinal flora dysfunction in mice with UC. In summary, our findings show that SP has a prophylactic and therapeutic effect in UC in vivo, thereby highlighting its broad medicinal applications.

Systematic review and meta-analysis of randomized controlled trials comparing botulinum toxin injection with lateral internal sphincterotomy for chronic anal fissure.

OBJECTIVE: The aim of this review is to systematically analyze the prospective randomized controlled trials on the efficacy of botulinum toxin injection (Botox) vs. lateral internal sphincterotomy (LIS) for the treatment of chronic anal fissure (CAF). MATERIALS AND METHODS: A systematic review of the literature was undertaken. The prospective randomized controlled trials on the effectiveness of Botox vs. LIS for the management of CAF were selected according to specific criteria and analyzed to generate pooling data. RESULTS: Four studies encompassing 279 patients were qualified for the meta-analysis. There was a statistically significant higher healing in LIS group compared with Botox group (RR 1.31[1.57, 1.50] 95% CI, z = 4.11, p < 0.0001). Absolute benefit increase rate (ABI) is 23% for LIS group compared with Botox group. The recurrence rate was statistically significantly higher in Botox groups than in LIS groups (RR 5.83[2.96, 11.49] 95% CI, z = 5.09, p < 0.00001).LIS was associated with a high rate of minor anal incontinence as compared to Botox (RR 0.08[0.01, 0.59] 95% CI, z = 2.47, p = 0.01). CONCLUSION: Botulinum toxin injection was associated with a higher rate of recurrent disease. LIS was more effective in healing chronic anal fissure.

Perianal mucinous adenocarcinoma arising from chronic anorectal fistulae: a review from single institution.

BACKGROUND: Mucinous adenocarcinoma arising from a chronic anorectal fistula is rare, with few reports in the literature. Such lesions can be misdiagnosed for the more common benign perianal abscess or fistula. METHODS: From our retrospective chart review, we identified three patients with chronic perianal fistula-in-ano who were subsequently found to have developed perianal mucinous adenocarcinoma on biopsy. We recorded the symptomatology, subsequent management and further follow-up of each patient. RESULTS: Two of three patients who received irradiation and chemotherapy were still alive during 28 and 24 months of follow-up, respectively without any evidence of distant metastasis. One patient with inguinal lymph node metastases died due to distant metastasis 6 months after diagnosis. CONCLUSIONS: Fistula-associated perianal mucinous adenocarcinoma is an uncommon malignant transformation of chronic fistula-in-ano. MRI can provide important diagnostic information on patient with this suspicious inflammatory condition. Although radical resection of the tumour with abdominoperineal resection remains the surgical treatment of choice. Combined chemoradiotherapy may be appropriate for these patients with promising results.

Wettability Manipulation by Interface-Localized Liquid Dielectrophoresis: Fundamentals and Applications.

Electric field-based smart wetting manipulation is one of the extensively used techniques in modern surface science and engineering, especially in microfluidics and optofluidics applications. Liquid dielectrophoresis (LDEP) is a technique involving the manipulation of dielectric liquid motion via the polarization effect using a non-homogeneous electric field. The LDEP technique was mainly dedicated to the actuation of dielectric and aqueous liquids in microfluidics systems. Recently, a new concept called dielectrowetting was demonstrated by which the wettability of a dielectric liquid droplet can be reversibly manipulated via a highly localized LDEP force at the three-phase contact line of the droplet. Although dielectrowetting is principally very different from electrowetting on dielectrics (EWOD), it has the capability to spread a dielectric droplet into a thin liquid film with the application of sufficiently high voltage, overcoming the contact-angle saturation encountered in EWOD. The strength of dielectrowetting depends on the ratio of the penetration depth of the electric field inside the dielectric liquid and the difference between the dielectric constants of the liquid and its ambient medium. Since the introduction of the dielectrowetting technique, significant progress in the field encompassing various real-life applications was demonstrated in recent decades. In this paper, we review and discuss the governing forces and basic principles of LDEP, the mechanism of interface localization of LDEP for dielectrowetting, related phenomenon, and their recent applications, with an outlook on the future research.

Cholesteric Flakes in Motion Driven by the Elastic Force from Nematic Liquid Crystals.

The paper presents a methodology to control the motion and orientation of suspended reflective cholesteric flakes in a nematic liquid crystal (LC) matrix. The flakes exhibit a dielectric anisotropy which controls their alignment with their in-plane axes parallel to an external electrical dc field. The elastic forces imposed by the LC host affect the switching behavior of the flakes and take care of the realignment to the planar state as soon as the dc field is switched off. When the LC host has a positive dielectric anisotropy, the switching voltage of the flakes is reduced by a factor of 2 in comparison with a LC host with negative dielectric anisotropy or in comparison with an isotropic host. We discovered that the LC host further regulates the back relaxation of cholesteric to return to the planar state upon retrieving the electric field. Whereas, in the isotropic fluid, flakes do not exhibit a preferred orientation when relaxed. Based on this newly proposed principle, we demonstrated its application as an optical switch for smart windows. Depending on the pitch of the cholesteric helix of the flakes, the light of a preset wavelength is reflected. Upon application of an electric field, the embedded flakes rotate their planes perpendicular to the substrate and consequently the incident light becomes fully transmitted without reflection or scattering of light.

Effect of exogenous spastin combined with polyethylene glycol on sciatic nerve injury.

Polyethylene glycol can connect the distal and proximal ends of an injured nerve at the cellular level through axonal fusion to avoid Wallerian degeneration of the injured distal nerve and promote peripheral nerve regeneration. However, this method can only prevent Wallerian degeneration in 10% of axons because the cytoskeleton is not repaired in a timely fashion. Reconstruction of the cytoskeletal trunk and microtubule network has been suggested to be the key for improving the efficiency of axonal fusion. As a microtubule-severing protein, spastin has been used to enhance cytoskeletal reconstruction. Therefore, we hypothesized that spastin combined with polyethylene glycol can more effectively promote peripheral nerve regeneration. A total of 120 male Sprague-Dawley rats were randomly divided into sham, suture, polyethylene glycol, and polyethylene glycol + spastin groups. In suture group rats, only traditional nerve anastomosis of the end-to-end suture was performed after transection of the sciatic nerve. In polyethylene glycol and polyethylene glycol + spastin groups, 50 µL of polyethylene glycol or 25 µL of polyethylene glycol + 25 µL of spastin, respectively, were injected immediately under the epineurium of the distal suture. Sensory fiber regeneration distance, which was used to assess early nerve regeneration at 1 week after surgery, was shortest in the suture group, followed by polyethylene glycol group and greatest in the polyethylene glycol + spastin group. Behavioral assessment of motor function recovery in rats showed that limb function was restored in polyethylene glycol and polyethylene glycol + spastin groups at 8 weeks after surgery. At 1, 2, 4 and 8 weeks after surgery, sciatic functional index values and percentages of gastrocnemius muscle wet weight were highest in the sham group, followed by polyethylene glycol + spastin and polyethylene glycol groups, and lowest in the suture group. Masson staining was utilized to assess the morphology of muscle tissue. Morphological changes in skeletal muscle were detectable in suture, polyethylene glycol, and polyethylene glycol + spastin groups at 1, 2, 4, and 8 weeks after surgery. Among them, muscular atrophy of the suture group was most serious, followed by polyethylene glycol and polyethylene glycol + spastin groups. Ultrastructure of distal sciatic nerve tissue, as detected by transmission electron microscopy, showed a pattern of initial destruction, subsequent disintegration, and gradual repair in suture, polyethylene glycol, and polyethylene glycol + spastin groups at 1, 2, 4, and 8 weeks after surgery. As time proceeded, axonal ultrastructure gradually recovered. Indeed, the polyethylene glycol + spastin group was similar to the sham group at 8 weeks after surgery. Our findings indicate that the combination of polyethylene glycol and spastin can promote peripheral nerve regeneration. Moreover, the effect of this combination was better than that of polyethylene glycol alone, and both were superior to the traditional neurorrhaphy. This study was approved by the Animal Ethics Committee of the Second Military Medical University, China (approval No. CZ20170216) on March 16, 2017.

Intravitreal anti-VEGF agents, oral glucocorticoids, and laser photocoagulation combination therapy for macular edema secondary to retinal vein occlusion: preliminary report.

AIM: To evaluate the efficacy and safety of combined anti-vascular endothelial growth factor (VEGF) agents, oral glucocorticoid, and laser photocoagulation therapy for macular edema (ME) secondary to retinal vein occlusion (RVO). METHODS: This study included 16 eyes of 16 patients with RVO-associated ME. Patients were initially treated with oral prednisone and an intravitreal anti-VEGF agent. Two weeks later, patients underwent standard laser photocoagulation. Best-corrected visual acuity (BCVA), central retinal thickness (CRT), and retinal vessel oxygenation were examined over 12mo. RESULTS: Patients received 1.43±0.81 anti-VEGF injections. Mean baseline and 12-month logMAR BCVA were 0.96±0.51 (20/178) and 0.31±0.88 (20/40), respectively, in eyes with central retinal vein occlusion (CRVO) (P<0.00), and 1.02±0.45 (20/209) and 0.60±0.49 (20/80), respectively, in eyes with branch retinal vein occlusion (BRVO) (P<0.00). At 12mo, CRT had significantly decreased in eyes with CRVO (P<0.00) and BRVO (P<0.00). Venous oxygen saturation had significantly increased in eyes with CRVO (P<0.00) and BRVO (P<0.00). No examined parameters were significantly different between the 2 RVO groups. No serious adverse effects occurred. CONCLUSION: Anti-VEGF, glucocorticoid, and photocoagulation combination therapy improves visual outcome, prolongs therapeutic effect, and reduces the number of intravitreal injections in eyes with RVO-associated ME.

Intravitreal Injection of Hydrogen Peroxide Induces Acute Retinal Degeneration, Apoptosis, and Oxidative Stress in Mice.

PURPOSE: Oxidative stress is a common pathological condition for multiple retinal diseases. Hydrogen peroxide (H2O2) has been applied as an oxidative stress inducer for the in vitro studies. Here, we report the in vivo effect of H2O2 exposure to the mouse retina and its underlying mechanism. METHODS: The H2O2 or saline solution was intravitreally injected into the eyes of female C57BL/6J mice for two consecutive days. The retinal structure was evaluated by in vivo imaging using spectral domain optical coherence tomography (OCT) and validated by histological assessment as well as retinal marker expression. In addition, retinal stress, cell apoptosis, and antioxidant enzyme expression were also determined. RESULTS: Retinal and outer nuclear layer thickness thinning was observed at days 7 and 14 by OCT imaging with the treatment of 10 µg H2O2, which was confirmed by the histopathological analysis. The expressions of photoreceptor (Rho, Rora, Rorb, and Rcvrn), bipolar cell (Chat and Calb2), and retinal pigment epithelial (Rpe65) markers were reduced in the H2O2-treated group, whereas the expression of retinal ganglion cell marker (Tubb3) was increased. TUNEL-positive cells were obviously found in the outer nuclear layer and inner nuclear layer of H2O2-treated mice but sparely found in the ganglion cell layer. Coherently, apoptotic gene expressions (Casp3, Casp9, Bax, and Parp8) were significantly increased in the retina with increasing dosages of H2O2, while Bcl2 expression was mildly decreased. In addition, the expressions of Gfap and antioxidant enzyme genes (Txn2, Sod2, and Gpx4) were significantly upregulated in the retina after the H2O2 treatment, compared to the vehicle control group. CONCLUSIONS: This study revealed that intravitreal injection of H2O2 induces acute retinal damage by increasing oxidative stress and cell apoptosis in the retina. This acute retinal degeneration mouse model could provide a platform for drug screening against oxidative stress and retinal diseases.