Pickering Emulsions of Thermotropic Liquid Crystals Stabilized by Amphiphilic Gold Nanoparticles.

We report emulsions of thermotropic liquid crystals (LCs) in water that are stabilized using amphiphilic gold nanoparticles (AuNPs) and retain their ability to respond to aqueous analytes for extended periods (e.g., up to 1 year after preparation). These LC emulsions exhibit exceptional colloidal stability that results from the adsorption of AuNPs that are functionalized with thiol-terminated poly(ethylene glycol) (PEG-thiol) and hexadecanethiol (C16-thiol) to LC droplet interfaces. These stabilized LC emulsions respond to the presence of model anionic (SDS), cationic (C12TAB), and nonionic (C12E4) surfactants in the surrounding aqueous media, as evidenced by ordering transitions in the LC droplets that can be readily observed using polarized light microscopy. Our results reveal significant differences in the sensitivity of the stabilized LC droplets toward each of these analytes. In particular, these stabilized droplets can detect the cationic C12TAB at concentrations that are lower than those required for bare LC droplets under similar experimental conditions (0.5 and 2 mM, respectively). These results demonstrate an enhanced sensitivity of the LC toward C12TAB when the PEG/C16-thiol-coated AuNPs are adsorbed at LC droplet interfaces. In contrast, the concentrations of SDS required to observe optical transformations in the stabilized LC droplets are higher than those required for the bare LC droplets, suggesting that the presence of the PEG/C16-thiol AuNPs reduces the sensitivity of the LC toward this analyte. When combined, our results show that this Pickering stabilization approach using amphiphilic AuNPs as stabilizing agents for LC-in-water emulsions provides a promising platform for developing LC droplet-based optical sensors with long-term colloidal stability as well as opportunities to tune the sensitivity and selectivity of the response to target aqueous analytes.

Decoding Optical Responses of Contact-Printed Arrays of Thermotropic Liquid Crystals Using Machine Learning: Detection and Reporting of Aqueous Amphiphiles with Enhanced Sensitivity and Selectivity.

Surfactants and other amphiphilic molecules are used extensively in household products, industrial processes, and biological applications and are also common environmental contaminants; as such, methods that can detect, sense, or quantify them are of great practical relevance. Aqueous emulsions of thermotropic liquid crystals (LCs) can exhibit distinctive optical responses in the presence of surfactants and have thus emerged as sensitive, rapid, and inexpensive sensors or reporters of environmental amphiphiles. However, many existing LC-in-water emulsions require the use of complicated or expensive instrumentation for quantitative characterization owing to variations in optical responses among individual LC droplets. In many cases, the responses of LC droplets are also analyzed by human inspection, which can miss subtle color or topological changes encoded in LC birefringence patterns. Here, we report an LC-based surfactant sensing platform that takes a step toward addressing several of these issues and can reliably predict concentrations and types of surfactants in aqueous solutions. Our approach uses surface-immobilized, microcontact-printed arrays of micrometer-scale droplets of thermotropic LCs and hierarchical convolutional neural networks (CNNs) to automatically extract and decode rich information about topological defects and color patterns available in optical micrographs of LC droplets to classify and quantify adsorbed surfactants. In addition, we report computational capabilities to determine relevant optical features extracted by the CNN from LC micrographs, which can provide insights into surfactant adsorption phenomena at LC-water interfaces. Overall, the combination of microcontact-printed LC arrays and machine learning provides a convenient and robust platform that could prove useful for developing high-throughput sensors for on-site testing of environmentally or biologically relevant amphiphiles.

Laser damage properties of LiB3O5 crystal surface under UV laser irradiation.

LiB3O5 (LBO) crystal has a very high bulk laser damage threshold. Laser damage often occurs on the surfaces with a large number of processing defects during application. In this paper, the surface laser damage threshold, damage growth threshold, and damage growth curve of LBO crystal and fused silica under the same processing process have been comparatively studied by using a 355 nm pulsed laser. The surface laser damage performance of LBO crystal has been comprehensive evaluated. The results show that the laser damage threshold and damage growth threshold of LBO are about twice that of fused silica, and the damage growth coefficient is about 0.7 times that of fused silica. The detection and analysis of impurity defects and photothermal weak absorption defects show that the subsurface defects of LBO crystal are less than that of fused silica. Laser damage morphologies show that the damage process is related to strongly bonded chemical structure and anisotropic physical characteristics of LBO crystal. These characteristics together determine the high threshold damage performance of LBO crystal. The results of this study are of great guidance for the application of LBO crystal in high-power laser systems.

Design and enhanced anticorrosion performance of a Zn5Mo2O11·5H2O/h-BN nanocomposite with labyrinth of nanopores.

Zinc molybdate (ZMO) is a safe and effective grafting material for anticorrosion. Herein, we reported the synthesis of ZMO/h-BN with the labyrinth of capillary pores owing to the in situ growth of ZMO on flake hexagonal boron nitride (h-BN) using the hydrothermal method. The special morphological structure provided a tortuous path for aggressive species to the steel substrate, which extended and blocked the transmission of aggressive species, enhancing the physical corrosion barrier performance. In addition, the capillary pores of ZMO contributed to the competitive adsorption of Cl- in an electrolyte and reduced the diffusion of aggressive species, thus further delaying the corrosion process. Moreover, the capture of oxygen by forming a B-O bond with h-BN and the formation of a molybdate passive film are beneficial for the inhibition of cathodic and anodic reactions. As verified by electrochemical impedance spectroscopy (EIS), the anticorrosion performance of ZMO/h-BN coating increased by 49.58% and 130.72% compared with ZMO and epoxy resin (EP) coatings after immersing in a NaCl aqueous solution (3.50 wt%) for 72 h. This coating matrix provides an avenue for molybdate-based corrosion remediation.

Sinomenium acutum: A Comprehensive Review of its Botany, Phytochemistry, Pharmacology and Clinical Application.

Sinomenium acutum is the dry stem of Sinomenium acutum (Thunb.) Rehd et Wils. (S. acutum) and Sinomenium acutum (Thunb.) Rehd. et Wils. var. cinereum Rehd. et Wils and is mainly distributed in China and Japan. As a traditional Chinese medicine (TCM) for dispelling wind and dampness in China, it is widely distributed and has a long history of drug use. In recent years, with the increase of the incidence of rheumatoid disease, S. acutum has become the focus of research. This paper reviews the literature on the chemical constituents, pharmacological effects, clinical applications and pharmacokinetics and safety of S. acutum from the past 60 years. At present, more than 210 natural compounds have been isolated from S. acutum, including alkaloids, lignans, triterpenoid saponins, steroids, and other structures. Pharmacological activities of S. acutum were mainly reported on anti-inflammatory, analgesic, anti-allergic, immunosuppressive, anti-tumor, liver-protective, anti-oxidative, and other effects, and clinical applications were mainly recorded on rheumatoid arthritis, ankylosing spondylitis, and other diseases. The clinical use of SIN has fewer side effects and more safety; only a small number of gastrointestinal reactions occurred, and the symptoms disappeared after the drug stopped. The purpose of this paper is to lay a foundation and provide reference for the follow-up research and wide application of S. acutum.

Assessing the UV-pulse-laser-induced damage density of fused silica optics using photo-thermal absorption distribution probability curves.

A photo-thermal absorption distribution probability curve based on a normal distribution model was proposed to describe the distribution of absorptive defects on fused silica surfaces under different processing conditions. Simultaneously, the maximum distribution probability absorption coefficient (MPA) and absorption distribution deviation (ADD) were used to quantitatively describe the overall absorption level and the uniformity of the absorption distribution on the fused silica surface. Based on this, the MPA (µ) and ADD (δ) were used to establish a statistical numerical relationship with the surface damage density of fused silica. The results showed that when µ ≤ 0.095 ± 0.015 and δ ≤ 0.045 ppm, the fused silica optics met the manufacturing process requirements for high laser-induced damage performance. Thus, a non-destructive approximate evaluation of the laser-induced damage density on the fused silica surface was achieved. This evaluation method provides a new, to the best of our knowledge, technology for evaluating the manufacturing process quality related to the damage performance of fused silica optics in high-power solid-state laser facilities and is an important supplement to popular destructive laser-induced damage testing methods.

Intraoperative Nice knots assistance for reduction in displaced comminuted clavicle fractures.

PURPOSE: The Nice knots have been widely used in orthopedic surgeries to fix torn soft tissue and fracture in recent years. The study aims to investigate the clinical efficacy and prognosis of intraoperative and postoperative Nice Knots-assisted reduction in the treatment of displaced comminuted clavicle fracture. METHODS: From Jan 2014 to Dec 2019, 75 patients diagnosed with unilateral closed displaced comminuted clavicle fracture were treated with open reduction and internal fixation (ORIF) in this study. Nice knot group (the NK group) included 38 patients and the other 37 patients were in the traditional group (the TK group). The time of operation and the amount of bleeding during operation were recorded. Post-operative clinical outcomes and radiographic results were recorded and compared between these two groups. The Visual Analogue Scale (VAS), Neer score, Rating Scale of the American Shoulder and Elbow Surgeons, Constant-Murley score and complications such as infection, nonunion, implant loosening, fragment displacement and hardware pain were observed in the two groups. RESULTS: In the comparison between the two groups, there was no significant difference in age, sex, the cause of displaced clavicle fracture, and other basic information between the two groups. The operation time, intraoperative fluoroscopy time, and intraoperative blood loss were significantly reduced in the NK group (P < 0.01). There were 2 cases of plate fracture in the TK group. The follow-up results showed that there was no significant difference in VAS, Neer score, ASES, and Constant-Murley scores between the two groups. CONCLUSION: The use of Nice knot, in comminuted and displaced clavicle fractures can reduce intraoperative blood loss, shorten operation time, facilitate intraoperative reduction, and achieve satisfactory postoperative clinical results. This study demonstrates that Nice knot is a simple, safe, practical and effective auxiliary reduction method.

Chemotaxonomy and cytotoxicity of the liverwort Porella Viridissima.

The first chemotaxonomic study based on volatile components of Porella viridissima (Mitt.) Grolle is reported. The GC-MS analysis of ether extract was performed; ten santalane and five pinguisane-type sesquiterpenes were identified together with perrottetianal A as major diterpene. Most of detected santalane-type sesquiterpenes are reported for the first time in liverwort. P. viridissima was found to belong to the chemotype III (pinguisane/sacculatane) and shared chemical similarities with P. navicularis. Perrotettianal A was isolated and has shown strong cytotoxicity against ovarian cancer.

Bilateral posterior fracture-dislocation of the shoulders: Two rare case reports and literature review.

RATIONALE: Bilateral posterior fracture-dislocation of the shoulders occurs rarely and the diagnosis is often challenging. This injury is often missed or delayed on initial presentation, leading to continuous pain, disability, and rising medical costs. Timely diagnosis and proper treatment are very important to restore shoulder function. PATIENT CONCERNS: Here we report 2 rare cases. Case 1 was a 53-year-old physical worker with severe pain and limited shoulder movement after an unexpected fall. Case 2 was a 55-year-old man with pain in upper limbs and shoulders after an electric shock. DIAGNOSIS: Both of them were diagnosed as bilateral posterior fracture-dislocation of the shoulders by computed tomography (CT) scan. INTERVENTION: After systematic preoperative evaluation, both of them were treated with open reduction and internal fixation. OUTCOMES: After 16 months follow-up, case 1 was pain-free in both shoulders. He had returned to full activity and was satisfied with his level of function. At 24 months follow-up, both shoulders of case 2 were painless and stable with acceptable range of motion and he was able to carry out daily activities. LESSONS: Our case reports highlight that bilateral posterior fracture-dislocation of the shoulders is easy to be missed; one way to prevent missing diagnosis is to suspect cases with pain and limited external rotation, especially those with a history of seizures, electric shock, or severe trauma; appropriate history inquiry, physical examination, proper shoulder images are the key to correct diagnosis.

Understanding the role of fluorine-containing plasma on optical properties of fused silica optics during the combined process of RIE and DCE.

Reactive ion etching (RIE) is crucial for fabricating high-quality fused silica optics since this technique can be used as a first step before dynamic chemical etching (DCE) for tracelessly removing the fractured defects in subsurface layer. The final quality of the optics is dramatically influenced by the plasma etching condition but still lacks sufficient information for practical application. In this work, combination of RIE and DCE was investigated deeply on polished fused silica surface by changing the gas type and flow rate. We show that the proper choice of fluorine-containing plasma condition during the RIE process allows the simultaneous occurrence of high surface quality and a low concentration of etching-introduced defects on fused silica. This leads to an ultrahigh laser-induced damage threshold at 355 nm while substantially keeping the surface roughness unchanged. This study paves the way for designing and developing a next-generation surface modification ability of high-quality fused silica with the great potential for high-power laser application.

α-Pyrone and Sterol Constituents of Penicillium aurantiacobrunneum, a Fungal Associate of the Lichen Niebla homalea.

Four new metabolites, 4-epi-citreoviridin (1), auransterol (3), and two analogues (2 and 4) of paxisterol (6), together with two known metabolites (15R*,20S*)-dihydroxyepisterol (5) and (6), were isolated from cultures of the fungal associate, Penicillium aurantiacobrunneum, of the lichen Niebla homalea, endemic to California and Baja California. The structures of all compounds were determined by comprehensive spectroscopic and spectrometric methods, as well as single-crystal X-ray diffraction for the determination of the absolute configuration of 3. Compound 1 showed selective cytotoxicity toward MCF-7 breast and A2780 ovarian cells with IC50 values of 4.2 and 5.7 µM, respectively.

Capping a glass thin layer on the etched surface via plasma chemical vapor deposition for improving the laser damage performance of fused silica.

Buffered HF-based etching can effectively improve the laser damage resistance of the fused silica, but deep etching would cause the deteriorations in surface roughness and hardness, and decrease the laser-induced damage threshold. Capping a glass thin layer on the etched surface via plasma chemical vapor deposition in one step could overcome those deteriorations. We found that the deposition of the glass thin layer can further reduce the impurity element contamination and the PL intensity while retaining the low subsurface defect density as well as for the deeply etched sample. The surface quality, surface hardness and the laser damage resistance of the fused silica can be significantly improved by the glass thin layer, which reveals the potential application in high power laser facility.

Plasma-Induced, Self-Masking, One-Step Approach to an Ultrabroadband Antireflective and Superhydrophilic Subwavelength Nanostructured Fused Silica Surface.

In this work, antireflective and superhydrophilic subwavelength nanostructured fused silica surfaces have been created by one-step, self-masking reactive ion etching (RIE). Bare fused silica substrates with no mask were placed in a RIE vacuum chamber, and then nanoscale fluorocarbon masks and subwavelength nanostructures (SWSs) automatically formed on these substrate after the appropriate RIE plasma process. The mechanism of plasma-induced self-masking SWS has been proposed in this paper. Plasma parameter effects on the morphology of SWS have been investigated to achieve perfect nanocone-like SWS for excellent antireflection, including process time, reactive gas, and pressure of the chamber. Optical properties, i.e., antireflection and optical scattering, were simulated by the finite difference time domain (FDTD) method. Calculated data agree well with the experiment results. The optimized SWS show ultrabroadband antireflective property (up to 99% from 500 to 1360 nm). An excellent improvement of transmission was achieved for the deep-ultraviolet (DUV) range. The proposed low-cost, highly efficient, and maskless method was applied to achieve ultrabroadband antireflective and superhydrophilic SWSs on a 100 mm optical window, which promises great potential for applications in the automotive industry, goggles, and optical devices.

Non-destructive evaluation of UV pulse laser-induced damage performance of fused silica optics.

The surface laser damage performance of fused silica optics is related to the distribution of surface defects. In this study, we used chemical etching assisted by ultrasound and magnetorheological finishing to modify defect distribution in a fused silica surface, resulting in fused silica samples with different laser damage performance. Non-destructive test methods such as UV laser-induced fluorescence imaging and photo-thermal deflection were used to characterize the surface defects that contribute to the absorption of UV laser radiation. Our results indicate that the two methods can quantitatively distinguish differences in the distribution of absorptive defects in fused silica samples subjected to different post-processing steps. The percentage of fluorescence defects and the weak absorption coefficient were strongly related to the damage threshold and damage density of fused silica optics, as confirmed by the correlation curves built from statistical analysis of experimental data. The results show that non-destructive evaluation methods such as laser-induced fluorescence and photo-thermal absorption can be effectively applied to estimate the damage performance of fused silica optics at 351 nm pulse laser radiation. This indirect evaluation method is effective for laser damage performance assessment of fused silica optics prior to utilization.

Monolayer Colloidal Crystals by Modified Air-Water Interface Self-Assembly Approach.

Hexagonally ordered arrays of polystyrene (PS) microspheres were prepared by a modified air-water self-assembly method. A detailed analysis of the air-water interface self-assembly process was conducted. Several parameters affect the quality of the monolayer colloidal crystals, i.e., the colloidal microsphere concentration on the latex, the surfactant concentration, the polystyrene microsphere diameter, the microsphere polydispersity, and the degree of sphericity of polystyrene microspheres. An abrupt change in surface tension was used to improve the quality of the monolayer colloidal crystal. Three typical microstructures, i.e., a cone, a pillar, and a binary structure were prepared by reactive-ion etching using a high-quality colloidal crystal mask. This study provides insight into the production of microsphere templates with flexible structures for large-area patterned materials.

Enhanced photoelectric properties by the coordinating role of doping and modification.

Dual technique design in this research has successfully enriched the complementation between doping and surface modification. Here, Co(2+) doped Ag-ZnO nanocomposites (CAZ NCs) are mass produced by the combustion method. The HRTEM image shows that the doped Co(2+) and the surface modified Ag nanoparticles on the ZnO NCs are influential on the preferential orientation. Based on the conductivity formula σ = nqµ and the actual verification, the improved photoelectric properties of CAZ NCs under visible light irradiation are attributed to the enhanced light absorption and the weakened recombination of photogenerated electron-hole pairs. It would be instructive for the sound design concept of subsequent material development.

A novel signal-on strategy for M.SssI methyltransfease activity analysis and inhibitor screening based on photoelectrochemical immunosensor.

In this work, a novel signal-on photoelectrochemical (PEC) immunosensor was fabricated for M.SssI methyltransfease (MTase) activity analysis and inhibitor screening based on an in situ electron donor producing strategy, where the anti-5-methylcytosine antibody was selected as DNA CpG methylation recognition unit, gold nanoparticle labeled streptavidin (SA-AuNPs) as signal amplification unit and alkaline phosphatase conjugated biotin (ALP-Biotin) as enzymatic unit. In the presence of M.SssI MTase, hairpin DNA1 containing the palindromic sequences of 5'-CCGG-3' in its stem was methylated. After hybridization with biotin-conjugated DNA2, the stem-loop structure of the hairpin DNA1 was unfolded and the duplex strand DNA (dsDNA) was formed. Then, the dsDNA was captured on the surface of anti-5-methylcytosine antibody modified electrode through the specific immuno-reaction. Afterwards, SA-AuNPs and ALP-Biotin was further captured on the electrode surface through the specific reaction between biotin and streptavidin. Under the catalysis effect of ALP towards ascorbic acid 2-phosphate trisodium salt (AAP), ascorbic acid (AA) was in situ produced as electron donor and a strong PEC response was obtained. The fabricated biosensor showed high detection sensitivity with low detection limit of 0.33unit/mL for M.SssI MTase. Furthermore, the inhibition research suggested that RG108 could inhibit the M.SssI MTase activity with the IC50 value of 152.54nM.

Trimester- and method-specific reference intervals for thyroid tests in pregnant Chinese women: methodology, euthyroid definition and iodine status can influence the setting of reference intervals.

OBJECTIVE: The importance of diagnosis and treatment of thyroid dysfunction during pregnancy has been widely recognized. We therefore established trimester- and method-specific reference intervals for thyroid testing in pregnant women according to the NACB recommended criteria. Several factors can affect the setting of reference intervals, in particular manufacturer's methodology, euthyroid definition and iodine status. DESIGN: Cross-sectional dataset analysis. SUBJECTS: Five hundred and five normal pregnant women at different stages of gestation were rigorously selected for setting reference intervals. All were healthy, iodine sufficient, euthyroid and negative for both serum thyroid peroxidase antibody (TPOAb) and thyroglobulin antibody (TgAb). MEASUREMENTS: Thyrotrophin (TSH), total and free thyroxine (TT4 and FT4), total and free triiodothyronine (TT3 and FT3) and anti-TPOAb and anti-TgAb were measured using the Bayer ADVIA Centaur system. Iodine content in drinking water, salt and urine was determined by national standard methods. The 2·5th and 97·5th percentiles were calculated as the reference intervals for thyroid hormone levels during each trimester. RESULTS: All participants had long-term consumption of iodized salt and median urinary iodine of 150-200 µg/l during each three trimester. The reference intervals for the first, second and third trimesters were, respectively, TSH 0·03-4·51, 0·05-4·50 and 0·47-4·54 mIU/l and FT4 11·8-21·0, 10·6-17·6 and 9·2-16·7 pmol/l. The manufacturer's method, euthyroid definition and iodine status may influence TSH and FT4 reference intervals. Alterations in thyroid hormone concentrations during pregnancy differed at different stage of gestation and to those of a nonpregnant state. CONCLUSIONS: The trimester- and method-based reference intervals for thyroid tests during pregnancy are clinically appropriate. Some variables should be controlled when establishing reference intervals.

[Distribution of noniodized salt and related affecting factors in Xinjiang].

OBJECTIVE: To find out the distribution of noniodized salt and related affecting factors in Xinjiang. METHOD: Using NTTST's iodized salt inspection Plan. RESULTS: A total number of 17 973 house holds being surveyed in which 69.4% of those used iodized salt and 30.5% used noniodizd salt. In northern Xinjiang, 7 672 households being surveyed in which 83.9% used iodized salt while in eastern Xinjiang 1 200 house holds being surveyed in which 62.2% used iodized salt. In southern Xinjiang, 9 101 house holds being surveyed in which 58.2% used iodized salt. Data showed a statistically significant difference (chi(2) = 1 329.87, P < 0.01). The noniodized salt comes from shop-on-wheels (57.4%) and rock salt (23.0%). The source of iodine was different in different areas. In eastern and southern Xinjiang it came from shop-on-wheels, while in northern Xinjiang came from retail sites. Factors related to the use of iodized salt were awareness about iodine deficiency disorders (IDD) and income. CONCLUSION: Programs on fighting against iodine deficiency in Xinjiang needs more attention, especially in the following aspects as publicity on IDD, administration of salt market and supervision system.