Adalimumab Dose Reduction and Withdrawal in Stable Non-Infectious Pediatric Uveitis: An Open-Label, Prospective, Pilot Study

PURPOSES

This study investigated the feasibility of adalimumab (ADA) dose reduction and withdrawal strategy in children with stable pediatric non-infectious uveitis (PNIU).

METHODS

This open-label prospective pilot trial recruited 18 stable PNIU patients (33 eyes) between two and eighteen years old who were treated with standard doses of ADA (20/40 mg every 2 weeks) plus oral methotrexate. The interval of ADA injection was extended to 4 weeks and followed up for 24 weeks. If the uveitis remained stable, ADA was discontinued and followed up for another 24 weeks. ADA was considered successfully stopped if no relapse occurred during this period. The relapse-free survival rate, best corrected visual acuity (BVCA), anterior chamber cell (ACC), vitritis, macular thickness (MT), and serum ADA levels were evaluated. Approval Number: 2021KYPJ201. ClinicalTrials.gov identifier: NCT05155592.

RESULTS

The relapse-free survival rate was 22.2% (4/18) at 48 weeks. 33.3% (6/18) of patients relapsed when ADA was given every 4 weeks, while 44.5% of patients (8/18) relapsed after ADA was stopped. The four patients successfully withdrawn from ADA were all diagnosed with BD. No statistically significant differences (p > 0.05) were observed in BCVA and MT between baseline and final follow-up. The proportion of ACC and vitritis exhibited an upward trend (p < 0.05) during follow-up. Serum ADA gradually decreased to zero during follow-up in both non-recurrence and recurrence groups.

CONCLUSIONS

In PNIU children who reached remission for 6 months, ADA dose reduction and withdrawal were associated with a high risk of inflammation recurrence. Timely adjustment of ADA to the last effective dosage frequency can regain control of the inflammation. Detection of ADA serum levels in patients with recurrence may help find the appropriate interval of ADA use.

Long-range distributed vibration sensing using phase-sensitive forward optical transmission: publisher's note

This publisher's note contains corrections to Opt. Lett.48, 4825 (2023)10.1364/OL.500587.

Super-long-range distributed vibration sensor based on the polarimetric forward-transmission of light

Undersea earthquake-triggered giant tsunamis pose significant threats to coastal areas, spanning thousands of kilometers and affecting populations, ecosystems, and infrastructure. To mitigate their impact, monitoring seismic activity in underwater environments is crucial. In this study, we propose a new, to the best of our knowledge, approach for monitoring vibrations in submarine optical cables. By detecting vibration-induced polarization rotation, our dual-wavelength fiber-optic sensing system enables precise measurement of acoustic/vibration amplitude, frequency, and position. As a proof of concept, a double-ended forward-transmission distributed fiber-optic vibration sensor was demonstrated with a single vibration source with a sensitivity of 3.4 mrad/µε at 100 Hz (20 m fiber on PZT), limit of detection of 1.7 pε/Hz1/2 at 100 Hz, sensing range of 121.5 km without an optical amplifier, spatial resolution of 5 m, and position error as small as 34 m. The vibration frequency range tested is from 0.01 to 100 Hz. The sensing system has several advantages, including elegant setup, noise mitigation, and super-long sensing distance.

Long-range distributed vibration sensing using phase-sensitive forward optical transmission

Long-range vibration sensing is an important tool for real-time structural health monitoring. A new, to the best of our knowledge, design of a distributed fiber-optic vibration sensor is introduced and experimentally demonstrated in this study. The proposed system utilizes the transmission of light in the forward direction for sensing, and a self-interference method for laser source simplification. To extract vibration information from phase modulation of light, two Mach-Zehnder interferometers (MZIs) are employed with a 3 × 3 coupler-based differential cross multiplication algorithm for phase calculation. A folded double-ended detection configuration allows the time-of-flight difference via cross correlation (CC) to provide vibration positioning. Experimental results demonstrate a sensing range of up to ∼80 km without optical amplification, accompanied by a position accuracy of 336 m.

[Pathological features of early gastric cancer and its background mucosa after eradication of Helicobacter pylori and their implications for biopsy diagnosis]

Objective: To investigate the clinicopathological changes of early gastric cancer, especially its background mucosa, after the eradication of Helicobacter pylori (H. pylori), and to investigate the causes of underdiagnosis in preoperative biopsy pathology. Methods: Ninety cases of early gastric cancer after H. pylori eradication and 120 cases of endoscopic submucosal dissection (ESD) specimens without H. pylori eradication and their corresponding biopsy specimens were collected from Beijing Friendship Hospital Affiliated to Capital Medical University during 2016-2021. The clinicopathological data of the patients were analyzed, and the histopathological characteristics and immunophenotypic results compared. Results: Compared with the early gastric cancer without H. pylori eradication history, the histopathological type of early gastric cancer after H. pylori eradication was differentiated adenocarcinoma, with staggered distribution of cancerous and non-cancerous epithelium in the tumor area. The morphologic characteristics of gastric mucosa in the background of early gastric cancer after H. pylori eradication, were distinctive, including widening of the opening of enterosylated glandular ducts, serrated change of luminal margin, eosinophilic and microvesicular cytoplasm of enterosylated epithelium. Low-grade atypia existed in gastric cancer epithelial cells after sterilization, which might lead to underdiagnosis or missed diagnosis in biopsy pathology. Conclusions: Early gastric cancer and its background mucosa after H. pylori eradication have unique morphological characteristics, which can be used as a clue for pathological diagnosis, improve the accuracy of biopsy pathology and reduce the underdiagnosis.

Screening of Endocrine Disrupting Potential of Surface Waters via an Affinity-Based Biosensor in a Rural Community in the Yellow River Basin, China

Overcoming the limitations of traditional analytical methods and developing technologies to continuously monitor environments and produce a comprehensive picture of potential endocrine-disrupting chemicals (EDCs) has been an ongoing challenge. Herein, we developed a portable nuclear receptor (NR)-based biosensor within 90 min to perform highly sensitive analyses of a broad range of EDCs in environmental water samples. Based on the specific binding of the fluorescence-labeled NRs with their ligands, the receptors were attached to the EDC-functionalized fiber surface by competing with EDCs in the samples. The biosensor emitted fluorescence due to the evanescent wave excitation, thereby resulting in a turn-off sensing mode. The biosensor showed a detection limit of 5 ng/L E₂-binding activity equivalent (E₂-BAE) and 93 ng/L T₃-BAE. As a case study, the biosensor was used to map the estrogenic binding activities of surface waters obtained from a rural community in the Yellow River basin in China. When the results obtained were compared with those from the traditional yeast two-hybrid bioassay, a high correlation was observed. It is anticipated that the good universality and versatility exhibited by this biosensor for various EDCs, which is achieved by using different NRs, will significantly promote the continuous assessment of global EDCs.

A comprehensive review on electrochemical and optical aptasensors for organophosphorus pesticides

There has been a rise in pesticide use as a result of the growing industrialization of agriculture. Organophosphorus pesticides have been widely applied as agricultural and domestic pest control agents for nearly five decades, and they remain as health and environmental hazards in water supplies, vegetables, fruits, and processed foods causing serious foodborne illness. Thus, the rapid and reliable detection of these harmful organophosphorus toxins with excellent sensitivity and selectivity is of utmost importance. Aptasensors are biosensors based on aptamers, which exhibit exceptional recognition capability for a variety of targets. Aptasensors offer numerous advantages over conventional approaches, including increased sensitivity, selectivity, design flexibility, and cost-effectiveness. As a result, interest in developing aptasensors continues to expand. This paper discusses the historical and modern advancements of aptasensors through the use of nanotechnology to enhance the signal, resulting in high sensitivity and detection accuracy. More importantly, this review summarizes the principles and strategies underlying different organophosphorus aptasensors, including electrochemical, electrochemiluminescent, fluorescent, and colorimetric ones.

Highly Transparent and Self-Healable Solar Thermal Anti-/Deicing Surfaces: When Ultrathin MXene Multilayers Marry a Solid Slippery Self-Cleaning Coating

Solar anti-/deicing can solve icing problems by converting sunlight into heat. One of the biggest problems, which has long been plaguing the design of solar anti-/deicing surfaces, is that photothermal materials are always lightproof and appear black, because of the mutual exclusiveness between generating heat and retaining transparency. Herein, a highly transparent and scalable solar anti-/deicing surface is reported, which enables the coated glass to exhibit high transparency (>77% transmittance at 550 nm) and meanwhile causes a >30 °C surface temperature increase relative to the ambient environment under 1.0 sun illumination. Such a transparent anti-/deicing surface can be fabricated onto a large class of substrates (e.g., glass, ceramics, metals, plastics), by applying a solid omniphobic slippery coating onto layer-by-layer-assembled ultrathin MXene multilayers. Hence, the surface possesses a self-cleaning ability to shed waterborne and oil-based liquids thanks to residue-free slipping motion. Passive anti-icing and active deicing capabilities are, respectively, obtained on the solar thermal surface, which effectively prevents water from freezing and simultaneously melts pre-formed ice and thick frost. The self-cleaning effect enables residue-free removal of unfrozen water and interfacially melted ice/frost to boost the anti-/deicing efficiency. Importantly, the surface is capable of self-healing under illumination to repair physical damage and chemical degradation.

[Study on the development of public health and safety literacy assessment scale for university freshmen]

Objective: To develop a measurement scale for the public health and safety literacy of university freshmen. Methods: Item pooling was conducted through literature review and in-depth interview with public health experts, and a nominal group was organized to develop the initial items to form the questionnaire. A total of 250 freshmen were randomly selected to complete the questionnaire, and the assessment of psychometric properties were performed to carry out item reduction by using classical test theory and item response theory. Exploratory factor analysis method (EFA) was employed to calculate the item-factor loadings. The data collected from another 318 freshmen were analyzed using confirmatory factor analysis method (CFA). Results: The scale contained 3 dimensions and 9 items with all content validity index ≥0.8. The difficulty coefficient of 9 items was 1.18-2.43. The discriminative validity analysis showed that the difficulty index was 0.41-0.78, and the discrimination index was 0.38-0.64. Each of the remaining items had a statistically significant difference in the score value between the top 27% and lowest 27% of respondents (t>3, P<0.05). The item's Cronbach's α was 0.72-0.77, corrected item-total correlation was 0.33-0.60 and the overall α of the scale was 0.77. EFA indicated all item-factor loading were higher than 0.680, and the accumulated variance contribution of the 3 factors was 62.484%. Results of CFA showed that the overall fitness index of the model reached the fitness standard except for the χ² value. There was no statistical significance in the total score of the scale and the scores of each item among groups with different demographic characteristics (P>0.05). Conclusions: The newly developed public health safety literacy scale had a good reliability,validity,stability and item constancy.It can be used in measurement of the public health and safety literacy of university freshmen.

Review of Optical Humidity Sensors

Optical humidity sensors have evolved through decades of research and development, constantly adapting to new demands and challenges. The continuous growth is supported by the emergence of a variety of optical fibers and functional materials, in addition to the adaptation of different sensing mechanisms and optical techniques. This review attempts to cover the majority of optical humidity sensors reported to date, highlight trends in design and performance, and discuss the challenges of different applications.

Femtosecond laser induced low propagation loss waveguides in a lead-germanate glass for efficient lasing in near to mid-IR

To support the growing landscape of near to mid-IR laser applications we demonstrate a range of low propagation loss femtosecond laser (FSL) written waveguides (WGs) that have achieved guided-mode laser operation in a rare earth (RE) doped lead-germanate glass. The WGs are fabricated in both the athermal and thermal FSL writing regimes using three different pulse repetition frequencies (PRF): 100 kHz (athermal); 1 MHz; and 5 MHz (thermal). The lasing capability of Yb³⁺ doped lead-germanate waveguides is verified in the near-IR. The refractive index contrast (∆n) for 100 kHz WGs is ~ 1 × 10^–4, while for 5 MHz, ∆n increases to ~ 5 × 10^–4. The WGs in the thermal regime are less effected by self-focusing and are larger in dimensions with reduced propagation losses. For the 1 MHz repetition rate thermal writing regime we report a low propagation loss WG (0.2 dB/cm) and demonstrate laser operation with slope efficiencies of up to ~ 28%.

[Adrenocortical oncocytic tumors: a clinicopathological analysis of 44 cases]

Objective: To study the clinicopathological features of adrenocortical oncocytic tumors (ACOT) and to compare the diagnostic values of Lin-Weiss-Bisceglia (LWB) score and Helsinki score. Methods: Forty-four cases of ACOT diagnosed at Beijing Friendship Hospital, China from March 2008 to July 2019 were histologically analyzed to evaluate their malignant potential (benign versus malignant) according to two scoring criteria. Immunohistochemical studies (EnVision method) were also used. Results: There were 23 males and 21 females with an average age of 46 years. Histologically, the tumor cells were arranged in trabecular, chrysanthemum-shaped, glandular and microcapsule structures, while clear cells were rare or absent. Most of the tumor cells were moderately atypical, and intranuclear inclusion bodies were conspicuous. Immunohistochemical staining showed that tumor cells were positive for Melan A, inhibin, Syn and calretinin. The average proliferation index was 3% in benign ACOT, about 5% in ACOT of malignant potential, and>20% in malignant ACOT. According to the LWB score, 61.4% (27/44) of the tumors were on the left side and had multiple lesions. The percentage of benign ACOT was 59.1% (26/44), malignant potential 6.8% (3/44), malignant 34.1% (15/44), respectively. Among the 15 malignant ACOT, the mitotic figures>5/50 HPF were found in 13 cases, necrosis in 11 cases and capsule invasion in 10 cases. According to the Helsinki score, 65.9% (29/44) of the tumors were benign, and 34.1% (15/44) were malignant. There was no significant difference between the two scoring standards (P>0.05). During the follow-up of 9 to 144 months, 31 patients survived without disease and 13 patients relapsed or had metastasis. Conclusions: ACOT more likely be benign than malignant. The left side is more common. Malignant tumors are prone to recurrence and metastasis. The morphological parameters (high mitotic index, necrosis, and capsular invasion) in the LWB scoring standards combined with immunohistochemical parameters (Ki-67) in the Helsinki score are helpful for the diagnosis of malignant ACOT and are important predictors of poor prognosis.

[Correlation analysis between serum ferritin level and liver damage in acute stage of dengue fever]

Objective: To investigate the correlation between serum ferritin (SF) level and liver damage in the acute stage of dengue fever. Methods: A retrospective study was conducted to analyze 171 cases diagnosed with dengue fever as dengue fever group and 130 healthy patients as control group in Hangzhou 3A grade hospital from July to December 2017. Clinical data, SF and liver function related indicators were collected from both groups: alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL) to analyze the correlation between liver damage and SF in patients with dengue fever. Results: ALT, AST, and SF levels were significantly higher in the dengue fever group than those in the healthy control group (Z = 11.553, 15.054 and 15.163, P < 0.001). SF levels were higher in the dengue fever combined with liver damage group than those without the liver damage group (z = 6.930, P < 0.001). However, there was no statistically significant differences in age, gender, peak body temperature, and history of liver disease (P > 0.05). In addition, Spearman's correlation analysis showed that SF was positively correlated with ALT, AST, and TBIL (r = 0.464, 0.531 and 0.315, P < 0.001). Among dengue patients with different SF levels, there were significant difference in ALT, AST levels and incidence of liver damage (H = 14.240 and 17.584, χ(2) = 49.547, P < 0.001). Patients with higher SF levels had higher ALT, AST levels and incidence of liver damage. Binary logistic regression analysis showed that hyperferritinemia (SF≥500 ng/ml) was the risk factor for dengue fever combined with liver damage (OR = 8.120, P < 0.001). Furthermore, ROC curve analysis showed that the AUC for SF to judge dengue fever combined liver damage was 0.846 (95% CI: 0.785-0.908), and the sensitivity and specificity when the SF cut-off value was 1 506 ng/ml were 74.8% and 83.3%. Conclusion: There is a certain correlation between the SF level and the degree of liver damage in acute stage of dengue fever patients, and hyperferritinemia is a risk factor for dengue fever combined with liver damage.

Highly efficient polarization-entangled photon-pair generation in lithium niobate waveguides based on bound states in continuum

Integrated optics provides a platform for the experimental implementation of highly complex and compact circuits for practical applications as well as for advances in the fundamental science of quantum optics. The lithium niobate (LN) waveguide is an important candidate for the construction of integrated optical circuits. Based on the bound state in the continuum (BIC) in a LN waveguide, we propose an efficient way to produce polarization-entangled photon pairs. The implementation of this method is simple and does not require the polarization process needed for periodically poled LN. The generation rate of the entangled photon pairs increases linearly with the length of the waveguide. For visible light, the generation efficiency can be improved by more than five orders of magnitude with waveguides having the length of only a few millimeters, compared with the corresponding case without BICs. The phenomena can appear in a very wide spectrum range from the visible to THz regions. This study is of great significance for the development of active integrated quantum chips in various wavelength ranges.

Light-sheet skew rays enhanced U-shaped fiber-optic fluorescent immunosensor for Microcystin-LR

A novel U-shaped fiber-optic evanescent-wave fluorescent immunosensor was designed that exploits light-sheet excitation of skew rays in a passive fiber for sensitive microcystin-LR (MC-LR) detection in real-time. In particular, a light sheet comprising a thin plane of light can be concentrated into exciting the optimum ray group, resulting in enhanced interaction between light and fluorophores. Meanwhile, skew rays excited by transmitting light into an optical fiber with an angle offset allow a much higher number of total-internal-reflections with increased interaction length along the fiber interface, which strengthens the light-matter interactions. Under the optimal angle offset, the proposed evanescent wave fluorescent immunosensor is the first demonstration of integrating light-sheet skew rays and a U-shaped fiber-optic probe for enhanced sensitivity. The results show that fluorescence sensitivity of the U-shaped fiber-optic probe with light-sheet skew rays excitation is 16 times higher than that of collimated skew rays excitation. Combined with this newly designed light-sheet skew rays enhanced U-shaped fiber-optic fluorescent immunosensor, a sensitive and real-time MC-LR detection method was established based on the indirect competitive immunoassay principle. Real environmental water samples spiked with MC-LR were determined by the immunosensor with recovery rates between 85% and 112%. The present system could be an alternative tool for the on-site environmental monitoring, in-field food safety assurance and clinical diagnostics. It also advances the fiber-optic sensors field in terms of experimental design.

[Anti-PD-1 therapy in advanced malignant liver tumor-induced type-1 diabetes mellitus: a case report]

Immune checkpoint inhibitor (ICI) has been emerged as a major breakthrough in tumor immunotherapy, but its unique mechanism of action has also led to a number of immune-related adverse events (irAE). Type 1 diabetes mellitus (T1DM) is one of the rarest irAEs. This paper reports a case of advanced malignant liver tumor-induced T1DM who received second-line anti-PD-1 therapy and showed initial symptoms of hyperosmolar coma and hyperglycemia. In addition, the relevant literature at home and abroad was collected and reviewed, and the clinical characteristics of T1DM induced by anti-PD-1 therapy were summarized with a view to achieve early detection, diagnosis and treatment.

Fiber-Optic Skew Ray Sensors

The evanescent fields along multimode fibers are usually relatively weak. To enhance the sensitivity of the resulting sensors, skew rays have been exploited for their larger number of total internal reflections and their more comprehensive spread over the fiber surface. The uniform distribution of light-matter interactions across the fiber surface facilitates high sensitivity through an increased interaction area, while mitigating the risk of laser-induced coating-material damage and photobleaching. Power-dependent measurements are less susceptible to temperature effects than interferometric techniques, and place loose requirements on the laser source. This review highlights the key developments in this area, while discussing the benefits, challenges as well as future development.

Light-Sheet Skew Ray-Enhanced Localized Surface Plasmon Resonance-Based Chemical Sensing

A stronger absorption of pump/probe light is desirable for maximizing the sensitivity to enable accurate measurements of trace chemical elements. We introduce a new sensing technique built on light-sheet excitation of skew rays in a multimode fiber with an additional enhancement of localized surface plasmon resonance (LSPR) and its evanescent-field hotspots between gold nanospheres on the coated fiber. A skewed light-sheet (i.e., a thin plane of light) can exploit the optimum ray group, producing enhanced and uniform interactions between light and matter for higher absorption/sensitivity and higher power threshold. The heightened evanescent field couples to the localized surface plasmon resonant modes to attain even greater sensitivity. We compared this excitation method with the previously demonstrated light-sheet skew ray-based sensor without LSPR and observed an enhancement in normalized attenuation of pump light up to seven orders of magnitude for low-concentration rhodamine B. The improvement in the normalized detection limit is almost three orders of magnitude. This new sensing technique uses a functionalized fiber rather than pairing a passive fiber with added functional particles in the analyte, which offers better area-selectivity. The potentially low-cost chemical sensors can be used on a range of sensing mechanisms such as pump/probe light absorption.

Strong terahertz magneto-optical phenomena based on quasi-bound states in the continuum and Fano resonances

We propose new ways to produce strong terahertz (THz) magneto-optical phenomena from monolayer graphene based on bound states in the continuum (BICs) and Fano resonances. The BICs and Fano resonances of radiation modes in the monolayer graphene are realized by designing the photonic crystal slab-graphene-slab structure. Based on them, the magnetic circular dichroism near 100% has been achieved. Importantly, such magneto-optical phenomena can be modulated in intensity and frequency using only electrostatic doping at a fixed magnetic field. Comparing two ways to produce magneto-optical phenomena, it is found that the way based on BICs exhibits some advantages such as good electrical tenability due to narrower resonance width, higher conversion efficiency and more stability with the change of incident angle. These phenomena can appear in a broad THz range by designing the nanostructures, which are very beneficial to polarization conversion and optoelectronic devices.

[Relationship of TLR2 and TLR4 expressions on the surface of peripheral blood mononuclear cells to small intestinal bacteria overgrowth in patients with hepatocellular carcinoma]

Objective: To investigate TLR2 and TLR4 expressional situation on the surface of peripheral blood mononuclear cells (PBMC) in patients with hepatocellular carcinoma (HCC) and their relationship with small intestinal bacterial overgrowth (SIBO). Methods: Flow cytometry was used to detect TLR2 and TLR4 expressional situation on the surface of PBMC in 78 cases with HCC, 56 cases with cirrhosis and 33 healthy controls. Furthermore, lactose hydrogen breath test (LHBT) was used to detect small intestinal bacterial overgrowth. Results: Of the 78 cases with HCC, 56 cases (71.8%) were SIBO-positive, 23 cases (41.1%) were SIBO- positive in 56 cases with cirrhosis, and 1 (3.0%) was SIBO-positive in 33 healthy controls. The incidence of SIBO in HCC patients was higher than cirrhosis patients (χ(2) = 12.72, P < 0.05) and healthy controls (χ(2) = 41.18, P < 0.05). The expression levels of TLR2 and TLR4 in HCC patients (100.55 ± 24.22, 42.76 ± 15.96) were significantly higher than cirrhosis (67.42 ± 18.36, 24.38 ± 8.68)and healthy control group (33.06 ± 11.72, 12.52 ± 4.46) (P < 0.05). Furthermore, the expression levels of TLR2 and TLR4 in SIBO-positive patients (108.75 ± 20.40, 48.1 ± 14.98) were higher than SIBO-negative patients (79.67 ± 20.60, 28.62 ± 7.36) (P < 0.05). Conclusion: The expression of TLR2 and TLR4 and the incidence of SIBO in HCC patients are significantly higher than cirrhosis and healthy control group. Moreover, the high expressions of TLR2 and TLR4 in SIBO-positive HCC patients may promote the development of HCC.

[A clinicopathological analysis of 21 cases of hepatolenticular degeneration]

Objective: To improve the diagnostic quality of hepatolenticular degeneration by summarizing the clinicopathological features. Methods: A retrospective analysis of 21 cases that were diagnosed as hepatolenticular degeneration with liver biopsy in our hospital from January 2013 to August 2018 was reviewed, and then their clinicopathologic features were analyzed. The pathomorphological differences between liver biopsy and liver biopsy after transplantation, and the relationship between histopathological patterns and biopsy types and clinical indicators were analyzed by Fisher's exact test. Results: Of the 21 patients with hepatolenticular degeneration, 10 patients had liver biopsy, and 11 patients underwent liver biopsy after liver transplantation. Among them, four cases were presented as simple fatty liver pattern (19.0%, 4/21), eight cases as steatohepatitis pattern (38.1%, 8/21), four cases as inflammatory necrosis without cirrhosis pattern (19.0%, 4/21), and five cases as inflammatory necrosis with cirrhosis pattern (23.9%, 5/21). Twelve cases had copper deposition in the liver (57.1%, 12/21), and the pattern of copper distribution in the liver was uneven. Conclusion: A clinicalpathological features of hepatolenticular degeneration mainly manifests in four patterns, but lack characteristic changes. Hence, comprehensive judgment should rely on clinical history, laboratory examination, genetic test results and liver histopathological changes.

Femtosecond-laser-written Microstructured Waveguides in BK7 Glass

There is a deficiency of low-loss microstructured waveguides that can be fabricated with a single laser-pass to minimize stress build-up, which can enable enhanced functionality and higher compactness for integrated optical devices. We demonstrate, for the first time, a series of multi-ring claddings each with a pair of cores in BK7 glass. Each waveguide was fabricated using only a single laser-pass at 1 MHz pulse repetition rate, 5 mm/s translation speed, 250 fs pulse width, over a set of pulse energies. We obtained the lowest-reported propagation loss of 0.062 dB/cm, measured at 1155 nm wavelength from the waveguide written with 340 nJ pulse energy. The maximum observed numerical aperture is 0.020, measured at 1155 nm wavelength from the waveguide written with 620 nJ pulse energy. Such waveguides could be incorporated in integrated Raman laser platforms for biomedical applications.

[Advances in the research of effects of glutamine on immune function of burn patients]

Glutamine is the most abundant amino acid found in plasma and cells. It is the preferred fuel for enterocytes in the small intestine, macrophages, and lymphocytes. After serious burn, increased requirement of glutamine by the gastrointestinal tract, kidney and lymphocytes, and relatively insufficient self synthesis likely contribute to the rapid decline of glutamine in circulation and cells. Glutamine supplementation can not only protect intestinal mucosa, maintain normal intestinal barrier function, reduce bacterial translocation, and enhance the intestinal immune function, but also increase the number of lymphocytes, enhance the phagocytic function of macrophage, promote the synthesis of immunoglobulin, and reduce the body's inflammatory response, so as to enhance the immune function. Therefore, glutamine supplementation can improve and enhance the immune function, reduce complications and promote the prognosis of severely burned patients.

Widely tunable, high slope efficiency waveguide lasers in a Yb-doped glass chip operating at 1 μm

Ultrafast laser inscribed waveguide lasers can lead to highly efficient and compact optical devices. This Letter reports an average lasing efficiency of 65%±2.5% from a multi-waveguide 2.5 mol. % ytterbium-doped ZrF₄-BaF₂-LaF₃-AlF₃-NaF (Yb:ZBLAN) chip in an extended-cavity configuration. A maximum output power of 750 mW with a lasing efficiency of 68% is also achieved. A monolithic end-coupled configuration reached a maximum output power of 784 mW with a lasing efficiency of 70%. The lasing wavelength is tuned from 1001 to 1045 nm in a Littrow configured cavity. A beam propagation factor of the lowest-order transverse-mode output was routinely achieved with an M² of 1.15.

Highly coherent free-running dual-comb chip platform

We characterize the frequency noise performance of a free-running dual-comb source based on an erbium-doped glass chip running two adjacent mode-locked waveguide lasers. This compact laser platform, contained only in a 1.2 L volume, rejects common-mode environmental noise by 20 dB thanks to the proximity of the two laser cavities. Furthermore, it displays a remarkably low mutual frequency noise floor around 10  Hz²/Hz, which is enabled by its large-mode-area waveguides and low Kerr nonlinearity. As a result, it reaches a free-running mutual coherence time of 1 s since mode-resolved dual-comb spectra are generated even on this time scale. This design greatly simplifies dual-comb interferometers by enabling mode-resolved measurements without any phase lock.

First-line icotinib versus cisplatin/pemetrexed plus pemetrexed maintenance therapy for patients with advanced EGFR mutation-positive lung adenocarcinoma (CONVINCE): a phase 3, open-label, randomized study

BACKGROUND

Icotinib has been previously shown to be non-inferior to gefitinib in non-selected advanced non-small-cell lung cancer patients when given as second- or further-line treatment. In this open-label, randomized, phase 3 CONVINCE trial, we assessed the efficacy and safety of first-line icotinib versus cisplatin/pemetrexed plus pemetrexed maintenance in lung adenocarcinoma patients with epidermal growth factor receptor (EGFR) mutation.

PATIENTS AND METHODS

Eligible participants were adults with stage IIIB/IV lung adenocarcinoma and exon 19/21 EGFR mutations. Participants were randomly allocated (1 : 1) to receive oral icotinib or 3-week cycle of cisplatin plus pemetrexed for up to four cycles; non-progressive patients after four cycles were maintained with pemetrexed until disease progression or intolerable toxicity. The primary end point was progression-free survival (PFS) assessed by independent response evaluation committee. Other end points included overall survival (OS) and safety.

RESULTS

Between January 2013 and August 2014, 296 patients were randomized, and 285 patients were treated (148 to icotinib, 137 to chemotherapy). Independent response evaluation committee-assessed PFS was significantly longer in the icotinib group (11.2 versus 7.9 months; hazard ratio, 0.61, 95% confidence interval 0.43-0.87; P = 0.006). No significant difference for OS was observed between treatments in the overall population or in EGFR-mutated subgroups (exon 19 Del/21 L858R). The most common grade 3 or 4 adverse events (AEs) in the icotinib group were rash (14.8%) and diarrhea (7.4%), compared with nausea (45.9%), vomiting (29.2%), and neutropenia (10.9%) in the chemotherapy group. AEs (79.1% versus 94.2%; P < 0.001) and treatment-related AEs (54.1% versus 90.5%; P < 0.001) were significantly fewer in the icotinib group than in the chemotherapy group.

CONCLUSIONS

First-line icotinib significantly improves PFS of advanced lung adenocarcinoma patients with EGFR mutation with a tolerable and manageable safety profile. Icotinib should be considered as a first-line treatment for this patient population.

[Efficiency of FibroScan and FibroTouch in liver stiffness measurement and fat quantification: a comparative analysis]

Objective: To investigate the efficiency of FibroScan(FS)and FibroTouch(FT)in liver stiffness measurement(LSM)and fat quantification through a comparative analysis. Methods: The outpatients or hospitalized patients who underwent LSM and fat quantification using FS and FT were enrolled. The differences in success rate and detecting parameters between FS and FT were analyzed, as well as the correlation between FS and FT values. The t-test was used for comparison of normally distributed continuous data between groups, and a one-way analysis of variance or the Kruskal-Wallis test was used for comparison between multiple groups. The Mann-Whitney U test was used for comparison of non-normally distributed continuous data between groups. Results: A total of 1621 patients were enrolled. The success rates of FT and FS were 100% and 94.96%, respectively, and the success rate of FS was influenced by sex, age, body mass index, and biochemical markers of liver function. FT has a significantly shorter duration of single detection and a significantly lower number of times of single detection than FS(duration of single detection: 190.21±38.78 s vs 220.89±68.36 s, P < 0.01; number of single detection times: 10.31±1.32 vs 11.81±3.76, P < 0.01), as well as a significantly lower ratio of interquartile range to median of fat quantification in the same patient(5.39%±4.81% vs 17.18%±14.07%, P < 0.01). The LSM and fat quantification of FS were significantly correlated with those of FT(r = 0.645 and 0.620, both Based on the duration and number of times of single detection, success rate, and stability of fat quantification, FT seems to have a better detection efficiency than FS. The detection values of FT and FS can be calculated with regression equations < 0.01). The equations of linear regression were LSM(FT)= 4.435+0.477×LSM(FS); CAP(FT)= 134.71+0.456×CAP(FS). Conclusion: Based on the duration and number of times of single detection, success rate, and stability of fat quantification, FT seems to have a better detection efficiency than FS. The detection values of FT and FS can be calculated with regression equations.

Ultra-fast Hygrometer based on U-shaped Optical Microfiber with Nanoporous Polyelectrolyte Coating

Real-time measurement of the relative humidity of air has applications ranging from process control to safety. By using a microfiber form-factor, we demonstrate a miniature and fast-response hygrometer with the shortest-ever response time (3 ms). The sensor head consists of an optical microfiber of 10 µm diameter and 2 mm length configured to form a compact U-shaped probe, and functionalized with a polyelectrolyte multilayer coating of 1.0 bilayer. The sensing mechanism is primarily water-absorption-based optical loss. We have measured a response time of 3 ms and a recovery time of 36 ms. The sensitivity is as high as 0.4%/%RH, and the detection limit is as low as 1.6%RH. The maximum relative humidity is 99%RH, before reaching a recoverable dew-point.

Self-corrected chip-based dual-comb spectrometer

We present a dual-comb spectrometer based on two passively mode-locked waveguide lasers integrated in a single Er-doped ZBLAN chip. This original design yields two free-running frequency combs having a high level of mutual stability. We developed in parallel a self-correction algorithm that compensates residual relative fluctuations and yields mode-resolved spectra without the help of any reference laser or control system. Fluctuations are extracted directly from the interferograms using the concept of ambiguity function, which leads to a significant simplification of the instrument that will greatly ease its widespread adoption and commercial deployment. Comparison with a correction algorithm relying on a single-frequency laser indicates discrepancies of only 50 attoseconds on optical timings. The capacities of this instrument are finally demonstrated with the acquisition of a high-resolution molecular spectrum covering 20 nm. This new chip-based multi-laser platform is ideal for the development of high-repetition-rate, compact and fieldable comb spectrometers in the near- and mid-infrared.

[A serum lipidomic study of patients with non-alcoholic fatty liver disease]

Objective: To investigate the serum lipidomic profile in patients with nonalcoholic fatty liver disease (NAFLD), and to analyze the lipid metabolism characteristics of NAFLD. Methods: The subjects were divided into control group (23 patients) and pathologically confirmed NAFLD group (42 patients), and ultra-high-performance liquid chromatography-tandem mass spectrometry was used to measure serum lipidomic metabolites. The partial least squares-discriminant analysis (PLS-DA) model was established to analyze the differences in lipid metabolism with reference to the univariate analysis. The t-test and Mann-Whitney U test were used for data analysis. Results: A total of 239 lipids were identified and qualitative and quantitative analyses were performed. The PLS-DA model (R2 = 0.753, Q2 = 0.456) and the univariate analysis showed that 77 lipids were metabolized differentially between the NAFLD group and the control group (VIP > 1, P < 0.05), including free fatty acid, phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, lysophosphatidylcholine, lysophosphatidylinositol (LPI), choline plasmalogen (PlsCho), ethanolamine plasmalogen (PlsEtn), ceramide (Cer), sphingomyelin, and triglyceride (TG). Compared with the control group, the NAFLD group had significant increases in monounsaturated fatty acids (increased by 39%, t = -3.954, P < 0.05) and TGs (increased by 36%, Z = -2.662, P < 0.05), mainly TGs with low numbers of carbon atoms and unsaturated bonds, while there were reductions in TGs with high numbers of carbon atoms and unsaturated bonds. In addition, compared with the control group, the NAFLD group had significant increases in the levels of LPI (increased by 223%, t = -3.858, P < 0.05) and Cer (increased by 21%, t = -2.481, P < 0.05) and significant reductions in PlsCho (reduced by 18%, t = 3.184, P < 0.05) and PlsEtn (reduced by 20%, t = 2.363, P < 0.05). Conclusion: There is a significant difference in lipid metabolism profile between NAFLD patients and healthy people, and a serum lipidomic analysis of NAFLD helps to further clarify the characteristics of lipid metabolism in patients with NAFLD.

[A clinical study of the association between hepatic controlled attenuation parameter and metabolic syndrome]

Objective: To investigate the association between hepatic controlled attenuation parameter (CAP) and metabolic syndrome (MetS) and the correlation of CAP and its changes with the incidence of MetS. Methods: A total of 2461 subjects who underwent physical examination from July 2013 to September 2015 were enrolled. Spearman correlation analysis was used to investigate the correlation of CAP with the number of MetS components and each MetS component, and the chi-square test was used to investigate the prevalence rates of MetS and each component under different CAP levels. Logistic regression analysis was used to analyze the odds ratio (95% confidence interval (CI)) of MetS under different CAP levels. A total of 230 subjects without baseline MetS were selected; in a prospective cohort study, these subjects were divided into groups according to the baseline CAP, change in CAP, and percent change in CAP, and the chi-square test was performed to compare the incidence of MetS. The Cox regression analysis was used to analyze the values of baseline CAP, change in CAP, and percent change in CAP in predicting MetS. Results: CAP was positively correlated with the number of MetS components (r = 0.309, P < 0.01) and significantly correlated with all components. There were significant differences in the prevalence rates of MetS and its components under different CAP levels (< 238 dB/m, 238-258 dB/m, 259-291 dB/m, and ≥292 dB/m) (P < 0.05). After the adjustment for sex and age, with < 238 dB/m as a reference, the odds ratios (95% CI) of MetS in patients with CAP levels of 238-258 dB/m, 259-291 dB/m, and ≥292 dB/m were 1.784 (1.369-2.325), 2.936 (2.292-3.760), and 4.363 (3.435-5.543), respectively (all P < 0.05). Follow-up data showed that 28 patients (12.2%) developed MetS. After the adjustment for related factors, the hazard ratios (95% CI) of MetS in patients with baseline CAP > 238 dB/m, change in CAP > 30 dB/m, and percent change in CAP > 25.0% were 3.337 (1.163-9.569), 7.732 (2.453-24.366), and 11.656 (3.329-40.813), respectively (all P < 0.05). Conclusion: CAP is closely associated with MetS and its components. CAP and its change can be used to predict the risk of MetS.

Photodetector based on Vernier-Enhanced Fabry-Perot Interferometers with a Photo-Thermal Coating

We present a new type of fiber-coupled photodetector with a thermal-based optical sensor head, which enables it to operate even in the presence of strong electro-magnetic interference and in electrically sensitive environments. The optical sensor head consists of three cascaded Fabry-Perot interferometers. The end-face surface is coated with copper-oxide micro-particles embedded in hydrogel, which is a new photo-thermal coating that can be readily coated on many different surfaces. Under irradiation, photons are absorbed by the photo-thermal coating, and are converted into heat, changing the optical path length of the probing light and induces a resonant wavelength shift. For white-light irradiation, the photodetector exhibits a power sensitivity of 760 pm/mW, a power detection limit of 16.4 μW (i.e. specific detectivity of 2.2 × 10⁵ cm.√Hz/W), and an optical damage threshold of ~100 mW or ~800 mW/cm². The response and recovery times are 3.0 s (~90% of change within 100 ms) and 16.0 s respectively.

Detection of microscopic defects in optical fiber coatings using angle-resolved skew rays

Microscopic defects in optical fiber coatings can be an impending catastrophe for high-power fiber laser and telecommunications systems and are difficult to detect with conventional methods. We demonstrate a highly sensitive interrogation technique that can readily identify faults such as microscopic nicks, scrapes, low-quality recoatings, and internal defects in fibers and their coatings, based on skew ray excitation and angle-resolved analysis.

Substrate-Independent, Transparent Oil-Repellent Coatings with Self-Healing and Persistent Easy-Sliding Oil Repellency

Herein we report a simple and substrate-independent approach to fabricate transparent oil-repellent coatings, which involves alternate deposition of poly(diallyldimethylammonium) (PDDA) and poly(styrenesulfonate) (PSS) onto substrates, followed by incubation of the coated objects into perfluorooctanoate (PFO) aqueous solutions for 2 min. Various low-surface-tension liquids can easily slide down the coating surfaces on flat substrates at a sliding angle lower than 12° for 10 μL droplets. The coatings are applicable to different substrates including Si, glass, plastic, steel, and wood, and those with complex shapes and large surface areas. They are also applicable to rough substrates with roughness at both micro/nanoscale and macroscopic scales to realize the easy-sliding oil repellency. Incubation of the PDDA/PSS polyelectrolyte multilayers (PEMs) into PFO solutions induces an effective but nondestructive substitution of PFO anions for PSS in the PEMs, which results in a composite coating with PFO anions homogeneously interspersed in both the coating surface and the bulk. Thanks to the as-described "repeating-layer" composition/structure of the coatings, their easy-sliding oil repellency can be self-healed after surface decomposition or well maintained after physical damages, due to the replenishing surface. Therefore, the advantageous characteristics of the as-developed oil-repellent coatings and the simplicity of the preparation protocol make the coatings highly practical for real-world applications. It is believed that the coatings can perform as antismudge coatings that shield against oil-borne contaminants, chemical-shield coatings that protect coated plastics from dissolution by organic solvents, and nonstick coatings (of oil tankers or pipelines) that enable loss-free oil transportation.

Cleaning of Oil Fouling with Water Enabled by Zwitterionic Polyelectrolyte Coatings: Overcoming the Imperative Challenge of Oil-Water Separation Membranes

Herein we report a self-cleaning coating derived from zwitterionic poly(2-methacryloyloxylethyl phosphorylcholine) (PMPC) brushes grafted on a solid substrate. The PMPC surface not only exhibits complete oil repellency in a water-wetted state (i.e., underwater superoleophobicity), but also allows effective cleaning of oil fouled on dry surfaces by water alone. The PMPC surface was compared with typical underwater superoleophobic surfaces realized with the aid of surface roughening by applying hydrophilic nanostructures and those realized by applying smooth hydrophilic polyelectrolyte multilayers. We show that underwater superoleophobicity of a surface is not sufficient to enable water to clean up oil fouling on a dry surface, because the latter circumstance demands the surface to be able to strongly bond water not only in its pristine state but also in an oil-wetted state. The PMPC surface is unique with its described self-cleaning performance because the zwitterionic phosphorylcholine groups exhibit exceptional binding affinity to water even when they are already wetted by oil. Further, we show that applying this PMPC coating onto steel meshes produces oil-water separation membranes that are resilient to oil contamination with simply water rinsing. Consequently, we provide an effective solution to the oil contamination issue on the oil-water separation membranes, which is an imperative challenge in this field. Thanks to the self-cleaning effect of the PMPC surface, PMPC-coated steel meshes can not only separate oil from oil-water mixtures in a water-wetted state, but also can lift oil out from oil-water mixtures even in a dry state, which is a very promising technology for practical oil-spill remediation. In contrast, we show that oil contamination on conventional hydrophilic oil-water separation membranes would permanently induce the loss of oil-water separation function, and thus they have to be always used in a completely water-wetted state, which significantly restricts their application in practice.

Effect of zinc-bearing zeolite clinoptilolite on growth performance, zinc accumulation, and gene expression of zinc transporters in broilers

This study investigated Zn-bearing zeolite clinoptilolite (Zn-ZCP) as a Zn supplement on performance, organ or tissue development, Zn accumulation in tissues, and gene expression of Zn transporters in the duodenum of broilers. A total of 300 1-d-old Arbor Acres chickens were randomly allocated to 5 dietary treatments with 6 replicate cages of 10 birds per treatment for a 21-d feeding period. The treatments comprised a basal corn–soybean meal diet without supplemental Zn (the control) or similar diets supplemented with 80 mg/kg Zn from ZnSO4 or 20, 40, or 80 mg/kg Zn from Zn- ZCP, respectively. Supplementation of Zn-ZCP had a positive effect on G:F (linear, P < 0.05) and had tendency difference on ADG (linear, P < 0.1) of broilers during 1 to 21 d. Incremental Zn-ZCP inclusion in the diet increased the fresh weight of the pancreas (linear, P < 0.05) and tibia (linear, P < 0.05) in broilers on d 14. The same trend to the fresh weight of the tibia (linear, P < 0.05) and pancreas (linear, P < 0.05) was observed on d 21. Increasing Zn-ZCP level showed a linear response on Zn concentration in the liver (linear, P < 0.001), pancreas (linear, P < 0.05), and tibia (linear, P < 0.05) on d 14. The same trend of Zn concentrations in pancreas (linear, P < 0.05) and tibia (linear, P < 0.001) was observed on d 21. The mRNA levels of Zn transporter 2 (ZnT-2) and Zn transporter 5 (ZnT-5) in the duodenum of chicks fed the diet with 80 mg/kg Zn from Zn-ZCP did not differ from those of chicks fed the control diet, but both were lower (P < 0.05) than those of chicks fed ZnSO4 diet. Metallothionein (MT) mRNA levels of broilers fed the diet supplemented with 80 mg/kg Zn from Zn-ZCP or ZnSO4 was higher (P < 0.05) than that in the control group. Dietary treatments did not affect the mRNA expression of Zn transporter 1 (ZnT-1) or metal response element-binding transcription factor-1 (MTF-1). In conclusion, as a Zn supplement, Zn-ZCP was comparable to ZnSO4 for enhancing Zn accumulation and growth performance of broilers during 1 to 21 d. Broilers fed the diet with 80 mg/kg Zn from Zn-ZCP had different expressions of ZnT-2 and ZnT-5 in the duodenum compared with those fed the ZnSO4 diet.

Effects of high thoracic epidural anesthesia on ischemic cardiomyopathy cardiac function and autonomic neural function

We aimed at observing the effects of high thoracic epidural anesthesia (HTEA) on cardiac structure and function, heart rate variability (HRV), and QT interval variation (QTV) in ischemic cardiomyopathy (ICM) patients with chronic heart failure. We divided 30 ICM patients into HTEA (N = 16) and control (N = 14) groups.The control group was treated with medication, and the HTEA group was treated with HTEA and medication for 4 weeks. We measured the changes in the left-ventricular end-diastolic diameter (LVEDd) and left-ventricular ejection fraction (LVEF) before and after treatment by using echocardiography and examined changes in HRV and QTV using ambulatory electrocardiogram. HTEA significantly narrowed the LVEDd, improved LVEF, significantly increased the HRV, and significantly reduced the QTV in the ICM group compared to the control group. HTEA significantly narrowed the ventricular chamber diameter size of ICM patients, enhanced myocardial contractility, increased myocardial electrical stability, and improved the cardiac structure and function.

Enhanced responsivity with skew ray excitation of reflection- and transmission-type refractometric sensors

The responsivity of optical fibers to refractive index can be enhanced using high-order skew rays compared with using meridional rays. Skew rays can have a much higher number of reflections with increased interaction length along the core-cladding interface, which gives rise to stronger interactions with the external medium. Reflection/transmission-type refractometric sensors based on twin-coupled-core and multimode fibers showed one/two orders of magnitude increase in responsivity with skew ray excitation. The responsivity and sensitivity for the two types are ~2000%/RIU, ~1400%/RIU, and 4.9×10⁻⁵  RIU, 7.0×10⁻⁵  RIU, respectively.

Compact acoustic sensor based on air-backed mandrel coiled with optical microfiber

We propose and demonstrate a compact acoustic sensor comprising a 2 μm diam, 35 mm length optical microfiber coiled around a 3 mm diam air-backed mandrel. Acoustic waves induce local pressure variations that change the mandrel diameter and thus the optical path length of the mode propagating in the microfiber. The phase modulation is detected via a single-fiber polarimetric interferometer. The low stiffness and minimum bend radii of microfibers gives rise to extremely small package sizes without compromising acoustic responsivity.

Intensive insulin therapy in severe acute pancreatitis: a meta-analysis and systematic review

OBJECTIVE

To assess the effect of intensive insulin therapy on outcomes of patients with severe acute pancreatitis.

METHODS

Relevant literatures cited in these electronic databases: Medline, Chinese Biomedical Literature Database, China National Knowledge Infrastructure (CNK1) database, and Excerpta Medical database (Embase) were systematically searched for randomized controlled trials (RCTs) in which intensive insulin therapy was used in severe acute pancreatitis. Length of hospitalization, acute physiology and chronic health evaluation II (APACHE II) score, incidence of complications, and adverse effects were recorded for statistical analysis. The methodological quality of the eligible studies was assessed by Jadad scale. The results were analysed by Revman 4.3 software.

RESULTS

Three studies, which included a total of 118 cases, were finally reviewed. The methodological quality of the trials varied substantially In patients with severe acute pancreatitis, intensive insulin therapy was associated with shorter length of hospitalization (weighted mean difference (WMD) = -12.13, 95% confidence interval (CI) [-15.48, 8.78], p > 0.00001) and lower APACHE II score after 72 hours treatment (WMD = -3.80, 95% CI [-4.88,2. 72], p > 0.00001). One study reported insulin-related adverse event.

CONCLUSION

In patients with severe acute pancreatitis, intensive insulin therapy could relieve the patient's condition earlier and shorten the length of hospitalization without serious adverse effect.

Compact optical microfiber phase modulator

A compact optical microfiber phase modulator with MHz bandwidth is presented. A micrometer-diameter microfiber is wound on a millimeter-diameter piezoelectric ceramic rod with two electrodes. When a voltage is applied to the piezoelectric ceramic, the rod is strained, leading to a phase change along the microfiber; because of the small size, the optical microfiber phase modulator can have as high as a few MHz bandwidth response.

Theoretical and experimental demonstrations of a microfiber-based flexural disc accelerometer

The proof-of-concept demonstration of a microfiber-based flexural disc accelerometer is presented. The reduced microfiber size and bending radii give rise to high device compactness and responsivity. A flexural disc accelerometer manufactured from a 10 mm long microfiber showed a performance of ~2.2 rad/g, with the responsivity expected to increase proportionally with the microfiber length.

Top-down heating for low substrate temperature synthesis of carbon nanotubes

A top-down heating method to allow for low-temperature large area synthesis of carbon nanotubes using plasma-enhanced chemical vapour deposition is introduced in this paper. The approach utilizes top-down electromagnetic heating rather than conventional heating from a substrate heater under the electrode. A temperature gradient is created between the Ni catalyst surface and the substrate using a metal thermal control barrier layer, on which carbon nanotubes are grown as a function of the bias voltage, hydrocarbon concentrations and growth conditions. The heat during growth is provided by the plasma or energy coupling to the catalyst via top-down heating, which based on the coupled power density and the cooling of the substrate, in addition to the thermal 'barrier layer' properties will dictate the temperature of the growth surface. This unique approach of top-down heating with suitable cooling schemes, coupled with thermal barriers allows for the low substrate temperature synthesis of carbon nanotubes, scalable to large areas.

Ultraviolet upconversion fluorescence in rare-earth-ion-doped Y2O3 induced by infrared diode laser excitation

Room-temperature ultraviolet emission of Tm(3+) ions at 298 ((1)I(6)-->(3)H(6)), 364 ((1)D(2)-->(3)H(6)), and 391 nm ((1)I(6)-->(3)H(5)) was obtained in Y(2)O(3):Yb(3+)-Tm(3+) by continuous-wave diode laser excitation of 980 nm. Power dependence analysis demonstrates that five- and six-photon upconversion processes populate the (1)D(2) and (1)I(6) states, respectively. We believe that the (1)D(2) population originates from the cross relaxation (1)G(4)+(3)F(4)-->(3)H(4)+(1)D(2) of the Tm(3+) ions, while subsequent energy transfer from Yb(3+) to Tm(3+) excites the (1)D(2) state to the upper (1)I(6) state. High multiphoton-induced ultraviolet emission is also expected for other trivalent rare-earth ions similar to Tm(3+).

Polyurea-Functionalized Multiwalled Carbon Nanotubes: Synthesis, Morphology, and Raman Spectroscopy

An in situ polycondensation approach was applied to functionalize multiwalled carbon nanotubes (MWNTs), resulting in various linear or hyperbranched polycondensed polymers [e.g., polyureas, polyurethanes, and poly(urea-urethane)-bonded carbon nanotubes]. The quantity of the grafted polymer can be easily controlled by the feed ratio of monomers. As a typical example, the polyurea-functionalized MWNTs were measured and characterized in detail. The oxidized MWNTs (MWNT-COOH) were converted into acyl chloride-functionalized MWNTs (MWNT-COCl) by reaction with neat thionyl chloride (SOCl2). MWNT-COCl was reacted with excess 1,6-diaminohexane, affording amino-functionalized MWNTs (MWNT-NH2). In the presence of MWNT-NH2, the polyurea was covalently coated onto the surfaces of the nanotube by in situ polycondensation of diisocyanate [e.g., 4,4'-methylenebis(phenylisocyanate)] and 1,6-diaminohexane, followed by the removal of free polymer via repeated filtering and solvent washing. The coated polyurea content can be controlled to some extent by adjusting the feed ratio of the isocyanato and amino groups. The structure and morphology of the resulting nanocomposites were characterized by FTIR, NMR, Raman, confocal Raman, TEM, EDS, and SEM measurements. The polyurea-coated MWNTs showed interesting self-assembled flat- or flowerlike morphologies in the solid state. The signals corresponding to that of the D and G bands of the carbon nanotubes were strongly attenuated after polyurea was chemically tethered to the MWNT surfaces. Comparative experiments showed that the grafted polymer species and structures have a strong effect on the Raman signals of polymer-functionalized MWNTs.