Thin Copper Plate Defect Detection Based on Lamb Wave Generated by Pulsed Laser in Combination with Laser Heterodyne Interference Technique.

Thin copper plate is widely used in architecture, transportation, heavy equipment, and integrated circuit substrates due to its unique properties. However, it is challenging to identify surface defects in copper strips arising from various manufacturing stages without direct contact. A laser ultrasonic inspection system was developed based on the Lamb wave (LW) produced by a laser pulse. An all-fiber laser heterodyne interferometer is applied for measuring the ultrasonic signal in combination with an automatic scanning system, which makes the system flexible and compact. A 3-D model simulation of an H62 brass specimen was carried out to determine the LW spatial-temporal wavefield by using the COMSOL Multiphysics software. The characteristics of the ultrasonic wavefield were extracted through continuous wavelet transform analysis. This demonstrates that the A0 mode could be used in defect detection due to its slow speed and vibrational direction. Furthermore, an ultrasonic wave at the center frequency of 370 kHz with maximum energy is suitable for defect detection. In the experiment, the size and location of the defect are determined by the time difference of the transmitted wave and reflected wave, respectively. The relative error of the defect position is 0.14% by averaging six different receiving spots. The width of the defect is linear to the time difference of the transmitted wave. The goodness of fit can reach 0.989, and it is in good agreement with the simulated one. The experimental error is less than 0.395 mm for a 5 mm width of defect. Therefore, this validates that the technique can be potentially utilized in the remote defect detection of thin copper plates.

High-Sensitivity Differential Helmholtz Photoacoustic System Combined with the Herriott Multipass Cell and Its Application in Seed Respiration.

A highly sensitive photoacoustic detection system using a differential Helmholtz resonator (DHR) combined with a Herriott multipass cell is presented, and its implementation to sub-ppm level carbon dioxide (CO2) detection is demonstrated. Through the utilization of erbium-doped optical fiber amplifier (EDFA), the laser power was amplified to 150 mW. Within the multipass cell, a total of 22 reflections occurred, contributing to an impressive 33.6 times improvement in the system sensitivity. The normalized noise equivalent absorption coefficient (NNEA) was 8.64 × 10-11 cm-1·W·Hz-1/2 [signal-to-noise ratio, (SNR) = 1] and according to the Allan variance analysis, a minimum detection limit of 500 ppb could be achieved for CO2 at 1204 s, which demonstrates the long-term stability of the system. The system was applied to detect the respiration of rice and upland rice seeds. It is demonstrated that the system can monitor and distinguish the respiration intensity and respiration rate of different seeds in real time.

A new prognostic model including platelet/lymphocyte ratio and International Prognostic Score 3 for freedom from progression in patients with previously untreated advanced classical Hodgkin lymphoma.

PURPOSE: We aimed to develop a new risk stratification tool to predict freedom from progression (FFP) for newly diagnosed advanced classical Hodgkin lymphoma (cHL). METHODS: We collected data from 386 patients with advanced cHL diagnosed between December 8, 2000 and October 29, 2018, and treated with curative intent with ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine) or an ABVD-equivalent regimen. Cases were randomly divided into training and validation cohorts at a ratio of 7:3. The new model was constructed based on the results of Cox proportional hazards model in the training cohort. Comparisons of discrimination between the new model and other models in the training and validation cohorts for FFP prediction were measured by time-dependent area under curve (tAUC) and Harrell's C-index. Calibration plots were constructed to compare the consistency between the predicted and observed estimates of survival probability for the new model in the training and validation cohorts. RESULTS: The new model (IPSPLR) composed of International Prognostic Score (IPS)-3 and platelet/lymphocyte ratio (PLR) provided four distinct risk groups. The IPSPLR showed better discriminative ability when compared with IPS-3 and IPS-7. The AUC of IPSPLR was consistently higher than that of IPS-3 and IPS-7 between 12 and 120 months. The C-index of the IPSPLR was higher than that of IPS-7 and IPS-3. The calibration plots showed an excellent agreement between the IPSPLR-predicted and observed estimates of 5-year FFP. CONCLUSION: The IPSPLR is an easily used tool for FFP prediction for newly diagnosed advanced cHL. Validation of this tool in other large datasets is needed.

Palm-Sized Laser Spectrometer with High Robustness and Sensitivity for Trace Gas Detection Using a Novel Double-Layer Toroidal Cell.

A palm-sized laser spectrometer has been developed for detecting trace gases based on tunable diode laser absorption spectroscopy in combination with a novel double-layer toroidal cell. With the benefit of a homemade electronic system and compact optical design, the physical dimensions of the sensor are minimized to 24 × 15× 16 cm3. A toroidal absorption cell, with 84 reflections in 2 layers for an effective optical path length of 8.35 m, was used to enhance the absorption signals of gaseous species. A homemade electronic system was designed for implementing a distributed feedback (DFB) diode laser controller, an analog lock-in amplifier, data acquisition, and communication. Calibration-free scanned wavelength modulation spectroscopy was employed to determine the concentration of the gas and reduce the random fluctuations from electronical noise and mechanical vibration. The measurement of CH4 in ambient air was demonstrated using a DFB laser at 1.653 µm. The rise time and fall time for renewing the gas mixture are approximately 16 and 14 s, respectively. Vibration and temperature tests have been carried out for verifying the performance of the spectrometer, and standard deviations of 0.38 ppm and 0.11 ppm for 20 ppm CH4 at different vibration frequencies and temperatures, respectively, have been determined. According to the Allan deviation analysis, the minimum detection limit for CH4 can reach 22 ppb at an integration time of 57.8 s. The continuous measurement of atmospheric CH4 for 2 days validated the feasibility and robustness of our laser spectrometer, providing a promising laser spectral sensor for deploying in unmanned aerial vehicles or mobile robots.

Implementation of the toroidal absorption cell with multi-layer patterns by a single ring surface.

We developed a type of toroidal multi-pass cell with multi-layer patterns based on the off-axis model. The effective path length of the original toroidal multi-pass cell is extended several roundtrips in comparison with the single-layer pattern, since the inner surface of the toroidal multi-pass cell is more efficiently utilized. The light pattern has been achieved by using the simple ring surface, which is easy to fabricate. The exact analytical equations for the design of the toroidal multi-pass cell were derived based on analytical vector calculations. A series of numerical ray tracing simulations is presented, and the maximum theoretical optical path length that can be reached is 30 m with a setup of 5 cm column radius. Furthermore, two practical spot patterns are demonstrated with a path length of 8.3 m for a two-layer pattern and 10 m for a three-layer pattern, with respective effective volumes of 63 mL and 94 mL. Furthermore, the fringe effect is substantially reduced to less than 0.5% by the usage of our designed mask.

Controllable Synthesis of Flower-Like MoS2 and Its Quick Photodegradation of Methylene Blue Under Visible Irradiation.

Molybdenum disulfide (MoS2) was synthesized via hydrothermal process under the assistance of citric acid, which exhibited high photocatalytic property in the application of methylene blue (MB) degradation. The flower ball microstructure of MoS2 changed with different amounts of citric acid. X-ray diffraction (XRD), Scanning electron microscope (SEM), UV-Vis diffuse reflectance spectra have been employed to characterize the samples. It improved the photocatalytic efficiency nearly 19.77% compared to MoS2 without citric acid. When H2O2 was added, the synergistic effect of MoS2 and hydrogen peroxide (H2O2) was observed in photocatalytic reaction system, which degraded MB completely within 40 min under visible light irradiation.

Halbach array assisted assembly of orderly aligned nickel nanowire networks as transparent conductive films.

The aspect ratio and arrangement of nanowires play an important role in achieving excellent optoelectronic performance for metal nanowire-based transparent conductive films (TCFs). However, limited to the technology and material properties, studies are always focused on only one of the issues. Here, a novel strategy for manipulating the relative aspect ratio and arrangement of nickel nanowires (NiNWs) at nanoscale by Halbach array assisted assembly technology is introduced. Head-to-tail nickel nanowire chains as large as hundreds of micrometers are formed as a result of the dipole-dipole interactions of wire-wire. The arrangement of nickel nanowires can be preciously controlled by layer-by-layer deposition. Notably, the alignment create a significant improvement on the optoelectronic performance of nickel nanowire TCFs. The optimized orderly aligned NiNWs TCFs demonstrate super optoelectronic performance (90 Ω sq-1, 86%) than disordered NiNW TCFs (200 Ω sq-1, 80%). Moreover, NiNW-based TCFs exhibit outstanding long-term oxidation stability at 80 °C over 30 d as well as high-temperature oxidization stability even up to 300 °C, that is the most stable metal nanowire-based TCFs in air as far as we know. The low-cost, good optoelectronic performance and excellent oxidation resistance of aligned NiNWs will make them as attractive alternatives to silver nanowires for TCFs application.

Quantum state-to-state study for (H-(D-),HD) collisions on two potential energy surfaces.

Quantum time-dependent wave-packet calculations have been carried out to explore the state-to-state dynamics of the ion-molecule (H-(D-),HD) collisions on two accurate ab initio potential energy surfaces in the collision energy range 0.2-1.2 eV. Total and final state-resolved integral and differential cross sections are elaborated in detail. The differential cross sections vary substantially with the collision energy, turning from predominantly backward-scattering at low collision energies to forward and sideways scattering bias at relatively high collision energies. The rebound, stripping and time-delayed mechanisms are found to be possible in (H-(D-),HD) collisions. A set of quasi-classical trajectory calculations were performed, and the results indicate that the backward-scattering peak is caused by the low impact parameter trajectories, while the trajectories of high impact parameter are responsible for the forward scattering. A set of representative state-to-state differential cross sections at collision energies 0.6 and 1.2 eV are also presented. Different reaction mechanisms are dominant in (H-(D-),HD) collisions at different collision energies, resulting in different product rovibrational state distributions. The differences between the dynamics results based on the two potential energy surfaces are also discussed.

High-Efficiency Microiterative Optimization in QM/MM Simulations of Large Flexible Systems.

We present here a double-optimizations-of-buffer-region (DOBR) microiterative scheme for high-efficiency energy minimizations of large, flexible systems in combined quantum-mechanical/molecular-mechanical (QM/MM) calculations. In the DOBR scheme, an entire system is divided into three regions: the core, buffer, and outer regions. The core region includes QM atoms and the MM atoms within a cutoff distance R1 to the QM atoms (denoted by MM1 atoms), and the buffer region consists of MM atoms within another cutoff distance R2 to MM1 atoms. Each DOBR microcycle involves two steps: First, QM atoms are assigned electrostatic-potential (ESP) charges, and the buffer and outer regions are optimized at the MM level with the core region kept frozen. Second, the core and buffer regions are optimized at the QM/MM level using the electrostatic embedding with the outer region kept frozen. The two steps are repeated until two optimizations converge at one structure. The DOBR scheme was tested in the optimizations of nucleobases solvated in water spheres of 30 Å radius, where the initial geometries were extracted from the trajectories of classical molecular dynamics simulations, and the cutoff distances R1 and R2 were set to 5.0 and 4.0 Å, respectively. For comparisons, the optimizations were also carried out by a "standard" scheme without microiteration and by the two-region microiterative (TRM) method. We found that the averaged number of QM calculations for the DOBR scheme is only ∼1% of that of the standard scheme and ∼6% of the TRM approach. The promising results indicate that the DOBR scheme could significantly increase the efficiency of geometry optimizations for large, flexible systems in QM/MM calculations.

State-resolved differential and integral cross sections for the Ne + H2 (+) (v = 0-2, j = 0) → NeH(+) + H reaction.

State-to-state quantum dynamic calculations for the proton transfer reaction Ne + H2 (+) (v = 0-2, j = 0) are performed on the most accurate LZHH potential energy surface, with the product Jacobi coordinate based time-dependent wave packet method including the Coriolis coupling. The J = 0 reaction probabilities for the title reaction agree well with previous results in a wide range of collision energy of 0.2-1.2 eV. Total integral cross sections are in reasonable agreement with the available experiment data. Vibrational excitation of the reactant is much more efficient in enhancing the reaction cross sections than translational and rotational excitation. Total differential cross sections are found to be forward-backward peaked with strong oscillations, which is the indication of the complex-forming mechanism. As the collision energy increases, state-resolved differential cross section changes from forward-backward symmetric peaked to forward scattering biased. This forward bias can be attributed to the larger J partial waves, which makes the reaction like an abstraction process. Differential cross sections summed over two different sets of J partial waves for the v = 0 reaction at the collision energy of 1.2 eV are plotted to illustrate the importance of large J partial waves in the forward bias of the differential cross sections.

Potential Energy Surfaces for the First Two Lowest-Lying Electronic States of the LiH2(+) System, and Dynamics of the H(+) + LiH ⇌ H2(+) + Li + Reactions.

Two new potential energy surfaces are established for the ground and first excited electronic states of the LiH2(+) system, which are important for the astrophysics-related H(+) + LiH(+) and H(+) + LiH reactions. The ab initio energy points are calculated using the complete active space self-consistent field and multireference configuration interaction method with aug-cc-pVQZ basis set. At each state, more than 40000 energy points are calculated. The spectroscopic constants of the diatoms and the topographical characters of the new surfaces are examined in detail, showing good agreement with the available literature results. The reaction probabilities, integral and differential cross sections, and rate constants for the H(+) + LiH ⇌ H2(+) + Li reactions are obtained by performing quantum dynamics calculations, and compared with the previous literature results. The reaction mechanisms are discussed in detail. It is shown that the new surfaces can be recommended for the dynamics study of the H(+) + LiH(+) and H(+) + LiH(+) reactions and other research including LiH2(+) based rovibrational spectra and cluster dynamics.

Quantum State-to-State Dynamics of the H + LiH → H2 + Li Reaction.

State-to-state quantum dynamics calculations for the H + LiH (v = 0-1, j = 0) → H2 + Li reactions are performed based on an ab initio ground electronic state potential energy surface (PES). Total and product state-resolved integral and differential cross sections and rate constants are calculated. The present total integral cross sections and rate constants for the H + LiH (v = 0, j = 0) reaction are found to be in agreement with previous literature results. Product state-resolved integral cross sections and rate constants reveal that the H2 products are preferred to be formed in their rovibrational excited states. The differential cross sections show that the intensity of forward scattering for the H2 products in their rovibrational excited states is stronger than other states. The mechanisms for the v = 0 and v = 1 reactions are found to be highly consistent with each other. Further, the influence of the stripping mechanism on the H + LiH reaction is studied. It is found that the stripping mechanism could be responsible for the decrease of the reactivity, the product state distribution, and scattering direction of the H2 products. It is related to the "attractive" feature of the underlying PES.

Endoscopic-Assisted Intraoral Three-Dimensional Reduction Mandibuloplasty.

BACKGROUND: Oriental people have a square face with a prominent mandibular angle, which means masculine and coarse and is considered to be an unappealing feature. Reduction mandibuloplasty has become popular in the orient in the past 2 decades, and the operation was frequently performed through the intraoral approach. But an invisible mandibular angle forces the surgeon to perform blind ostectomy which leads to difficulty in performing an accurate ostectomy as planned, leaving unnatural mandibular contours and severe complications. METHODS: From January 2010 to January 2013, a total of 112 patients with prominent mandibular angles underwent one-stage long-curved ostectomy combined with splitting corticectomy through an intraoral approach with endoscopic assistance for reduction of the lower face. A retractor with an adjustable endoscope provides a clear operative field; the ostectomy line was marked. The one-stage long-curved ostectomy and corticectomy were performed following the marked ostectomy line using an oscillating saw with angles of various degrees and length under direct vision. RESULTS: Mandibular contouring was 3-dimensionally refined; the width of the lower face was reduced in the frontal view and the mandibular angle appeared natural and inconspicuous in the lateral view. The majority of patients were satisfied with both their frontal and lateral appearances. The gonial angle and the mandibular plane angle were increased effectively. No major complications such as fracture or facial nerve injury occurred. CONCLUSIONS: Intraoral approach of long-curved ostectomy combined with splitting corticectomy with endoscopic assistance allows surgeons to perform accurate, safe, and reproducible ostectomies and to recontour mandible 3-dimensionally, which can make the face look thinner from the frontal view and, in the lateral view, keeps it more natural looking with smooth ostectomized borders.

Upregulation of hyaluronan-mediated motility receptor in hepatocellular carcinoma predicts poor survival.

Hepatocellular carcinoma (HCC) is one of the most common types of cancer across the world. Hyaluronic acid (HA) has been reported to serve an important role in tumor extension, progression, migration and invasion. In addition, the receptor for HA-mediated motility (RHAMM) has been demonstrated to be overexpressed in different types of cancer. However, whether the upregulation of RHAMM contributes to hepatocarcinogenesis of HCC remains unclear. The present study examined the RHAMM expression in 187 HCC patients by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry (IHC). RHAMM expression was significantly upregulated in liver cancer tissues compared with that observed in adjacent normal liver tissues. The IHC analysis demonstrated that RHAMM was overexpressed in 18 (72.0%) of the 25 HCC tissues. Furthermore, overexpression of RHAMM was associated with tumor-node-metastasis (TNM), the presence of vascular invasion and recurrence. Notably, the present study indicated that the overexpression of RHAMM was closely associated with the shorter disease-free and overall survival, so it may be a potential independent predictor for disease-free and overall survival of HCC patients. In conclusion, the upregulation of RHAMM is associated with HCC progression and prognosis; and it may be a potential independent predictor of disease-free and overall survival of HCC following surgical resection.

[Association of HLA-DM gene with childhood systemic lupus erythematosus].

OBJECTIVE: To explore the association of HLA-DM gene with childhood systemic lupus erythematosus (SLE). METHODS: DMA and DMB genes were genotyped by sequence-based typing(SBT)in 79 SLE patients at our hospital from 2003 to 2006 and 57 normal controls. RESULTS: The frequency of DMB*0101/0102 was lower significantly in SLE patients than that in controls (5.1% vs 21.1%). And the frequency of DMB*0102/0102 in SLE patients with renal involvement was higher than that in controls (17.6% vs 1.8%, P < 0.05). The frequency of all alleles and other genotypes had no significance in SLE patients, SLE patients with different organ involvements and controls. CONCLUSION: As a protective gene, DMB*0102/0102 may be a susceptible allele for SLE patients with renal involvement.

[The relationship of leptin and adiponectin with insulin resistance in nonalcoholic fatty liver disease].

OBJECTIVES: To investigate the serum leptin and adiponectin levels in nonalcoholic fatty liver disease (NAFLD) patients, and their relationship with insulin resistance. METHODS: A total of 120 cases were enrolled and divided into two groups: NAFLD group (n = 60) and normal control group (n = 60). The serum levels of leptin and adiponectin were measured by ELISA. The body mass index (BMI), waist-to-hip ratio (WHR), triglyceride (TG), total cholesterol (Tchol), high-density lipoprotein cholesterol (HDL-C) , aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transpeptidase (GGT), fasting blood glucose (FBG) and HOMA-IR (homeostasis model assessment insulin resistance) were detected and analyzed. RESULTS: Compared with control group, the serum leptin level in NAFLD group was Significantly higher [(12.37+/-1.99) microg/L vs (5.20+/-1.03) microg/L, P less than 0.01], while the serum adiponectin level was significantly lower [(12.69+/-2.83) mg/L vs (22.83+/-4.61) mg/L, P less than 0.01]. HOMA-IR was also much higher in NAFLD group than that in control group[(4.86+/-0.63) vs (1.91+/-0.41), P less than 0.01]. Logistic regression analysis showed that leptin was positively correlated with WHR (beta value = 8.175, P less than 0.01), HOMA-IR (beta value = 0.974, P less than 0.01 ), FBG (beta value = 0.564, P less than 0.01 ). In contrast, adiponectin inversely associated with HOMA-IR (beta value = -0.495, P less than 0.01 ) and BMI (beta value = -0.314, P less than 0.01) respectively. CONCLUSION: The increased serum leptin level and decreased serum adiponectin level in NAFLD patients independently associated with HOMA-IR.

[Macrophage activation syndrome in Chinese children with systemic onset juvenile idiopathic arthritis].

OBJECTIVE: To review and analyze the clinical features, treatment, and outcome of macrophage activation syndrome (MAS) in children with systemic onset juvennil rheumatoid arthritis (SOJRA). METHOD: Retrospective review and analysis were performed on cases with MAS from a prospectively collected database of children with SOJRA from the year of 2003 to 2006 in the Hospital. RESULTS: Twenty four patients (21 boys, 3 girls) were diagnosed as having MAS with SOJRA. Mean age of the patients with MAS at diagnosis was 7 years, and the duration prior to diagnosis of MAS was 12 months. No trigger factors were found except in one case whose MAS was triggered by use of methotrexate and in another by parvovirus B19 infection. High grade fever, new onset hepatosplenomegaly and lymphadenopathy, pancytopenia, liver dysfunction were common clinical features in all the 24 cases (100%). Bleeding from skin, mucous membrane and gastrointestinal tract were noted in 9 cases (38%). Twelve (50%) cases had CNS dysfunction (high intracranial pressure, seizure and coma). Six cases (25%) developed ARDS. One patient suffered from renal damage. The laboratory test revealed elevated live enzymes and ferritin, decreased value of ESR, albumin, complete blood count and fibrinogen in all the 24 cases. Bone marrow examination supported the diagnosis of definite hemophagocytosis in the 24 cases. Lymph node biopsy was done for one case and histopathological examination showed that the node was full of activated macrophage. As to treatment, five cases only received high dose steroids (three of them died), 14 cases were treated with high dose steroids plus cyclosporine (one died), two were treated with steroids plus cyclosporine and etoposide (none died). The causes of deaths were ARDS and CNS involvement. In three of the cases who died, treatment was given up by their parents. CONCLUSIONS: MAS is a rare and potentially fatal complication of SOJRA. Most of our patients were male. Bone marrow studies support the diagnosis. CNS involvement and ARDS were poor prognostic signs. Early diagnosis and aggressive therapy are essential.