2.4 ng/√Hz low-noise fiber-optic MEMS seismic accelerometer.

This paper introduces a fiber-optic microelectromechanical system (MEMS) seismic-grade accelerometer that is fabricated by bulk silicon processing using photoresist/silicon dioxide composite masking technology. The proposed sensor is a silicon flexure accelerometer whose displacement transduction system employs a light intensity detection method based on Fabry-Perot interference (FPI). The FPI cavity is formed between the end surface of the cleaved optical fiber and the gold-surfaced sidewall of the proof mass. The proposed MEMS accelerometer is fabricated by one-step silicon deep reactive ion etching with different depths using the composite mask, among which photoresist is used as the etching-defining mask for patterning the etching area while silicon dioxide is used as the depth-defining mask. Noise evaluation experiment results reveal that the overall noise floor of the fiber-optic MEMS accelerometer is 2.4 ng/H z at 10 Hz with a sensitivity of 3165 V/g, which is lower than that of most reported micromachined optical accelerometers, and the displacement noise floor of the optical displacement transduction system is 208 fm/H z at 10 Hz. Therefore, the proposed MEMS accelerometer is promising for use in high-performance seismic exploration applications.

High-Speed Interrogation for Large-Scale Fiber Bragg Grating Sensing.

A high-speed interrogation scheme for large-scale fiber Bragg grating (FBG) sensing arrays is presented. This technique employs parallel computing and pipeline control to modulate incident light and demodulate the reflected sensing signal. One Electro-optic modulator (EOM) and one semiconductor optical amplifier (SOA) were used to generate a phase delay to filter reflected spectrum form multiple candidate FBGs with the same optical path difference (OPD). Experimental results showed that the fastest interrogation delay time for the proposed method was only about 27.2 us for a single FBG interrogation, and the system scanning period was only limited by the optical transmission delay in the sensing fiber owing to the multiple simultaneous central wavelength calculations. Furthermore, the proposed FPGA-based technique had a verified FBG wavelength demodulation stability of ±1 pm without average processing.

Study on Misalignment Angle Compensation during Scale Factor Matching for Two Pairs of Accelerometers in a Gravity Gradient Instrument.

A method for automatic compensation of misalignment angles during matching the scale factors of two pairs of the accelerometers in developing the rotating accelerometer gravity gradient instrument (GGI) is proposed and demonstrated in this paper. The purpose of automatic scale factor matching of the four accelerometers in GGI is to suppress the common mode acceleration of the moving-based platforms. However, taking the full model equation of the accelerometer into consideration, the other two orthogonal axes which is the pendulous axis and the output axis, will also sense the common mode acceleration and reduce the suppression performance. The coefficients from the two axes to the output are δO and δP respectively, called the misalignment angles. The angle δO, coupling with the acceleration along the pendulous axis perpendicular to the rotational plane, will not be modulated by the rotation and gives little contribution to the scale factors matching. On the other hand, because of coupling with the acceleration along the centripetal direction in the rotating plane, the angle δP would produce a component with 90 degrees phase delay relative to the scale factor component. Hence, the δP component coincides exactly with the sensitive direction of the orthogonal accelerometers. To improve the common mode acceleration rejection, the misalignment angle δP is compensated by injecting a trimming current, which is proportional to the output of an orthogonal accelerometer, into the torque coil of the accelerometer during the scale factor matching. The experimental results show that the common linear acceleration suppression achieved three orders after the scale factors balance and five orders after the misalignment angles compensation, which is almost down to the noise level of the used accelerometers of 1~2 × 10−7 g/√Hz (1 g ≈ 9.8 m/s²).

Scale Factor Calibration for a Rotating Accelerometer Gravity Gradiometer.

Rotating Accelerometer Gravity Gradiometers (RAGGs) play a significant role in applications such as resource exploration and gravity aided navigation. Scale factor calibration is an essential procedure for RAGG instruments before being used. In this paper, we propose a calibration system for a gravity gradiometer to obtain the scale factor effectively, even when there are mass disturbance surroundings. In this system, four metal spring-based accelerometers with a good consistency are orthogonally assembled onto a rotary table to measure the spatial variation of the gravity gradient. By changing the approaching pattern of the reference gravity gradient excitation object, the calibration results are generated. Experimental results show that the proposed method can efficiently and repetitively detect a gravity gradient excitation mass weighing 260 kg within a range of 1.6 m and the scale factor of RAGG can be obtained as (5.4 ± 0.2) E/µV, which is consistent with the theoretical simulation. Error analyses reveal that the performance of the proposed calibration scheme is mainly limited by positioning error of the excitation and can be improved by applying higher accuracy position rails. Furthermore, the RAGG is expected to perform more efficiently and reliably in field tests in the future.

Ultra-Weak Fiber Bragg Grating Sensing Network Coated with Sensitive Material for Multi-Parameter Measurements.

A multi-parameter measurement system based on ultra-weak fiber Bragg grating (UFBG) array with sensitive material was proposed and experimentally demonstrated. The UFBG array interrogation principle is time division multiplex technology with two semiconductor optical amplifiers as timing units. Experimental results showed that the performance of the proposed UFBG system is almost equal to that of traditional FBG, while the UFBG array system has obvious superiority with potential multiplexing ability for multi-point and multi-parameter measurement. The system experimented on a 144 UFBG array with the reflectivity of UFBG ~0.04% for the four target parameters: hydrogen, humidity, temperature and salinity. Moreover, a uniform solution was customized to divide the cross-sensitivity between temperature and other target parameters. It is expected that this scheme will be capable of handling thousands of multi-parameter sensors in a single fiber.

Multi-Task Joint Learning Model for Chinese Word Segmentation and Syndrome Differentiation in Traditional Chinese Medicine.

Evidence-based treatment is the basis of traditional Chinese medicine (TCM), and the accurate differentiation of syndromes is important for treatment in this context. The automatic differentiation of syndromes of unstructured medical records requires two important steps: Chinese word segmentation and text classification. Due to the ambiguity of the Chinese language and the peculiarities of syndrome differentiation, these tasks pose a daunting challenge. We use text classification to model syndrome differentiation for TCM, and use multi-task learning (MTL) and deep learning to accomplish the two challenging tasks of Chinese word segmentation and syndrome differentiation. Two classic deep neural networks­bidirectional long short-term memory (Bi-LSTM) and text-based convolutional neural networks (TextCNN)­are fused into MTL to simultaneously carry out these two tasks. We used our proposed method to conduct a large number of comparative experiments. The experimental comparisons showed that it was superior to other methods on both tasks. Our model yielded values of accuracy, specificity, and sensitivity of 0.93, 0.94, and 0.90, and 0.80, 0.82, and 0.78 on the Chinese word segmentation task and the syndrome differentiation task, respectively. Moreover, statistical analyses showed that the accuracies of the non-joint and joint models were both within the 95% confidence interval, with pvalue < 0.05. The experimental comparison showed that our method is superior to prevalent methods on both tasks. The work here can help modernize TCM through intelligent differentiation.

Sulfonated polydivinylbenzene bamboo-like nanotube stabilized Pickering emulsion for effective oxidation of olefins to 1,2-diol.

Sulfonated polydivinylbenzene bamboo-like nanotube (SPDVB) with effective olefins oxidation activity is prepared by combining cationic polymerization and sulfonation. By merely adjusting sulfonation time, SPDVB with different sulfonic acid group (-SO3H) contents is achieved. SPDVB is used as both a solid emulsifier and catalyst to fabricate Pickering emulsion interface catalytic system for oxidizing olefins with 30% H2O2 acting as oxidant/water phase and olefins acting as reactants/oil phase. It is shown that Pickering emulsion interface catalytic system stabilized by SPDVB exhibits enhanced olefins oxidation efficiency than the conventional ones. At the optimum catalyst and reaction condition, the conversion of olefins by Pickering emulsion interface catalytic system stabilized by SPDVB for cyclohexene, 1-methylcyclohexene, cyclooctene, 2,3-dimethyl-2-butene oxidation is higher than 90.00% and the corresponding 1,2-diol selectivity exceeds 93.00% except the selectivity to 1-methyl-1,2-cyclohexanediol. The catalytic system also exhibits excellent cycling performance (>95.00% olefins conversion and >89.00% 1,2-diol selectivity for cyclohexene/2,3-dimethyl-2-butene oxidation after four cycles). A possible mechanism for oxidation of olefins to 1,2-diol by SPDVB stabilized Pickering emulsion is proposed: the high catalytic interface area between sulfonic acid group and H2O2 in water phase enhances the sulfonic acid group of SPDVB to convert into peroxysulfonic acid (catalytic activity centre) firstly; then the formed peroxysulfonic acid attacks the double bond of olefins to form epoxide intermediates, which will be hydrolyzed to 1,2-diol.

Modeling and Analysis of the Noise Performance of the Capacitive Sensing Circuit with a Differential Transformer.

Capacitive sensing is a key technique to measure the test mass movement with a high resolution for space-borne gravitational wave detectors, such as Laser Interferometer Space Antenna (LISA) and TianQin. The capacitance resolution requirement of TianQin is higher than that of LISA, as the arm length of TianQin is about 15 times shorter. In this paper, the transfer function and capacitance measurement noise of the circuit are modeled and analyzed. Figure-of-merits, including the product of the inductance L and the quality factor Q of the transformer, are proposed to optimize the transformer and the capacitance measurement resolution of the circuit. The LQ product improvement and the resonant frequency augmentation are the key factors to enhance the capacitance measurement resolution. We fabricated a transformer with a high LQ product over a wide frequency band. The evaluation showed that the transformer can generate a capacitance resolution of 0.11 aF/Hz1/2 at a resonant frequency of 200 kHz, and the amplitude of the injection wave would be 0.6 V. This result supports the potential application of the proposed transformer in space-borne gravitational wave detection and demonstrates that it could relieve the stringent requirements for other parameters in the TianQin mission.

A MEMS Micro-g Capacitive Accelerometer Based on Through-Silicon-Wafer-Etching Process.

This paper presents a micromachined micro-g capacitive accelerometer with a silicon-based spring-mass sensing element. The displacement changes of the proof mass are sensed by an area-variation-based capacitive displacement transducer that is formed by the matching electrodes on both the movable proof mass die and the glass cover plate through the flip-chip packaging. In order to implement a high-performance accelerometer, several technologies are applied: the through-silicon-wafer-etching process is used to increase the weight of proof mass for lower thermal noise, connection beams are used to reduce the cross-sensitivity, and the periodic array area-variation capacitive displacement transducer is applied to increase the displacement-to-capacitance gain. The accelerometer prototype is fabricated and characterized, demonstrating a scale factor of 510 mV/g, a noise floor of 2 µg/Hz1/2 at 100 Hz, and a bias instability of 4 µg at an averaging time of 1 s. Experimental results suggest that the proposed MEMS capacitive accelerometer is promising to be used for inertial navigation, structural health monitoring, and tilt measurement applications.

A high-sensitivity MEMS gravimeter with a large dynamic range.

Precise measurement of variations in the local gravitational acceleration is valuable for natural hazard forecasting, prospecting, and geophysical studies. Common issues of the present gravimetry technologies include their high cost, high mass, and large volume, which can potentially be solved by micro-electromechanical-system (MEMS) technology. However, the reported MEMS gravimeter does not have a high sensitivity and a large dynamic range comparable with those of the present commercial gravimeters, lowering its practicability and ruling out worldwide deployment. In this paper, we introduce a more practical MEMS gravimeter that has a higher sensitivity of 8 µGal/√Hz and a larger dynamic range of 8000 mGal by using an advanced suspension design and a customized optical displacement transducer. The proposed MEMS gravimeter has performed the co-site earth tides measurement with a commercial superconducting gravimeter GWR iGrav with the results showing a correlation coefficient of 0.91.

[Prognostic Significance of CD45dimCD117+ Cells in Patients with Acute Myeloid Leukemia after Complete Remission].

OBJECTIVE: To investigate the predictive value of CD45dimCD117+ phenotype-abnormal cells (hereinafter referred to as "abnormal cells") for relapse and prognosis in adult patients with acute myeloid leukemia (AML) within 2 weeks after the first complete remission (CR1). METHODS: The clinical data of patients with newly diagnosed AML (non-acute promyelocytic leukemia) admitted in our department from July 1, 2014 to June 30, 2017 were analyzed retrospectively, and the relationship between clinical features at the initial diagnosis and the abnormal phenotype cells of CD45dimCD117+ within 2 weeks after CR1 with the prognosis were analyzed. RESULTS: A total of 91 patients with CD45dimCD117+ abnormal cells were detected. The median age was 51 years old, the median WBC count was 11.60×109/L, and the median ratio of bone marrow blast cells was 0.35 at initial diagnosis. According to the FAB classification, 1 (1.1%), 7 (7.7%), 38 (41.7%), 20 (22.0%), 21 (23.1%) and 4 (4.4%) patients were classifice as M0, M1, M2, M4, M5, and M6, respectively. According to the NCCN risk stratification, 30 (33.0%), 51 (56.0%), and 10 (11.0%) patients were determined as good, moderate, and poor prognosis, respectively. The median ratio of abnormal cells within 2 weeks after CR1 was 1.8500 (0.0236-8.0000)%. The median time from initiation of induction therapy to the acquisition of CR was 46 days, median recurrence-free survival time was 319 days, and median overall survival time was 352 days. A total of 45 patients relapsed, of which 14 died; 46 patients did not relapse, of which 3 died. The cutoff of abnormal cells by receiver operating characteristic curve (ROC) analysis was 2.055% (Se=0.733，Sp=0.761). The abnormal cell ratio was＞2.055% in 44 patients, the median ratio of abnormal cells was 3.075%, among which 33 patients relapsed and 12 patients died; the abnormal cell ratio was ＜2.055% in 47 patients, the median ratio of abnormal cells was 1.150%, 12 patients relapsed and 5 patients died. Regression analysis showed that WBC count＞50×109/L and abnormal cell ratio＞2.055% were independent risk factors for recurrence. The abnormal cell ratio＞2.055% group had a 2-year RFS rate of 54.3% and a 2-year OS rate of 52.8%. The abnormal cell ratio＜2.055% group had a 2-year RFS rate of 86.6% (P=0.018), and a 2-year OS rate of 85.3% (P＜0.05). CONCLUSION: For adult AML patients, CD45dimCD117+ phenotypical abnormal cells ratio＞2.055% within 2 weeks after CR1 is an independent risk factor for recurrence, which also is an dverse factor for RFS and OS.

[Effect of Stably Down-regulating FMI Expression of K562 Cells on Sensitivity of K562 cells to Imatinib Mesylate].

OBJECTIVE: To investigate the effect of stably down-regulating the FMI expression of K562 cells on the sensitivity of K562 cells to Imatinib (IM) and its possible mechanism. METHODS: Western-blot was used to detect the expression of FMI protein in K562 cells and peripheral blood mononuclear cells from the patients with chronic myelogenous leukemia, chronic myeloid blast crisis and healthy volunteers. The specific interference sequences targeting at the human FMI gene were designed and ligated into the lentiviral vector LV3; the three plasmid system-packaged lentivirus particles were used to transfect K562 cells to screen K562 cells that stably down-regulated FMI. CCK-8 assay and flow cytometry were used to determine effect of IM on cell proliferation and apoptosis. The transcription level of FMI and Fz8 in leukemia cells was detected by fluorescent quantitative PCR. The protein expression levels of FMI, Fz8, NFAT1, BCR-ABL and ß-catenin in leukemia cells were detected by Western-blot. RESULTS: The expression of FMI protein could be detected in peripheral blood mononuclear cells of the patients with CML-BC and K562 cells, the FMI expression could not be detected in all the patients with CML-CP and healthy volunteers. The recombinant lentiviral vector LV3/FMI had been successfully constructed the lentivirus was packaged, and the K562 cells stably down-regulating the FMI protein were screened. After stable down-regulation of FMI expression in K562 cells, the proliferation rate of leukemia cells decreased and the apoptosis rate was increased under the same drug concentration. Both the transcription and protein expression levels of Fz8 decreased. The NFAT1 total protein level increased, as well as the nuclear translocation of protein was enhanced. There was no significant change in the expression level of BCR-ABL fusion protein. The expression level of ß-catenin protein decreased. CONCLUSION: After the stable down-regulation of FMI expression, the sensitivity of K562 cells to IM and apoptosis of cells increase, which are performed possibly by inhibiting the FMI-Fz8 signaling pathway and activating the Ca2+-NFAT and Wnt/ß-catenin signaling pathway.

[Multivariate Analysis of Factors Influencing Recovery from Hemorrhagic Cystitis after Allo-HSCT].

OBJECTIVE: To analyze the incidence of hemorrhagic cystitis (HC) after allogeneic hematopoietic stem cell transplantation and the factors affecting HC, so as to provide clinical evidence for further treatment of HC. METHODS: The HC of 113 patients after allogeneic hematopoietic stem cell transplantation in Affiliated Hospital of Xuzhou Medical University between the years 2014-2016 was analyzed respectively. All cases of HC were divided into HC group and non-HC(control) group. The follow-up time: from preeonditionig day to 180 d after transplantation. The 10 clinical parameters were selected for univariate analysis with COX regression analysis: sex, age (＜25 years and 25 years), primary disease, conditioning regimen with anti-thymoglobulin(ATG), sex-mismatch in recipients, haploidential HSCT, cytomegalovirus (CMV) viremia, EB viremia, graft-versus-host disease (GVHD), and primary disease relapse, the factors significant at the 0.1 level in univariate analysis should be further evaluated by multivariate analysis using a COX regression analysis. The difference was significant at P＜0.05 in multivariate analysis. RESULTS: The HC occured in 31 of 113 patients (27.4%), with 5 cases of grade I (5.5%), 19 of grade II (16.8%), 5 of grade III (4.4%), and 2 of grade IV (1.8%). The median time of HC onset was 37 days (26-70 d) after transplantation. The median duration of HC was 14 days (5-55d). Univariate analysis showed that conditioning with anti-thymoglobulin (ATG) (RR=6.170, 95%CI: 1.875-20.306, P＜0.01), CMV viremia (RR=7.633, 95%CI：2.318-25.133) (P＜0.01), haploidentical HSCT (RR=0.307, 95%CI：0.137-0.686, P＜0.01), GVHD (RR=1.891, 95%CI：0.918-3.898, P＞0.05) were the risk factors for recovery from HC. The multivatiate analysis of above-mentioned risk factors with statistical significance showed that only CMV viremia (RR=4.770, 95%CI: 1.394-16.326, P＜0.05) was the indentified risk factor affecting the recovery from HC. CONCLUSION: Monitoring CMV viremia and antivirotic treatment are effective measurs to prevent the occurrence of HC and promote the recovery from HC.

[Risk Factors and Prognosis of Hepatic cGVHD after Allogeneic Hematopoietic Stem Cell Transplantation].

OBJECTIVE: To analyze the risk factors and prognosis of hepatic chronic GVHD after allogeneic hematopoietic stem cell transplantation (allo-HSCT). METHODS: The clinical data of 147 patients undergoing allo-HSCT from January 2013 to December 2016 were analyzed, the correlation between recipient age and sex, disease state, matched degree of HLA, donor sex, stem cell sources, ATG in GVHD prophylaxis, liver dysfunction during conditioning period, pre-transplant HBsAg, prior aGVHD and hepatic cGVHD were studied, and the correlation between hepatic cGVHD and prognosis were analysed. RESULTS: Thirty-two patients had hepatic cGVHD, cumulative incidence of 26.4%. In univariate analysis, pre-transplant HBsAg+and liver dysfunction during conditioning period were not significantly related with hepatic cGVHD (P>0.05). In multivariate analysis, prior acute GVHD (HR=2.087, P=0.045) was the independent risk factor for hepatic cGVHD, ATG (HR=0.231, P=0.000) was significantly related with a lower incidence of hepatic cGVHD. In univariate analysis, patients with hepatic cGVHD had a lower 2 years relapse rate (P=0.038). CONCLUSION: Prior acute GVHD is the independent risk factor for hepatic cGVHD, the ATG can significantly reduce the incidence of hepatic cGVHD. Hepatic cGVHD has been found to relate with a lower 2 years relapse rate.

[Relationship between BCR-ABLIS and Prognosis and Affecting Factors for Prognosis in CML Patients Treated with TKI for 12 Months].

OBJECTIVE: To evaluate the long-term prognosis of CML patients whose BCR-ABL transcript level was warning and best response at 12 months of treatment with tyrosine kinase inhititor (TKI), and to investigate the factors affecting therapeutic efficacy and prognosis. METHODS: The clinical data of patients with newly diagnosed CML were analyzed retrospectively. According to BCR-ABL transcript level, the 80 patients were divided into group A and group B, the patients with BCR-ABLIS >0.1% and ≤ 1% (warning response) were entolled in group A, and the patients with BCR-ABLIS ≤ 0.1% (best response) were enrolled in group B as control. The ratio of patients with main molecular response (MMR) and deep molecular response (DMR), as well as aquistation rate and cummulative rate of MR4 (DMR) at specified fine points in 2 groups were compared, the independent risk factors affecting the therapeutic efficacy and prognosis were analyzed. RESULTS: The MMR and MR4 of the B group at 15, 18 and 24 months after TKI treatment were significantly higher than those of the A group, and the patients in the B group reached MR4 faster. In the 3 months, 6 months and 12 months after the demarcation point (TKI 12 months), the A group was much less easy to obtain MR4 (P<0.05) than the B group. Through survival analysis, there were more patients in the B group than the A group at different time points to reach MR4, and the difference was statistically significant (P<0.01). The single factor analysis showed that the splenomegaly (below rib edge)> 10cm (P<0.01) and lactate dehydrogenase > 400 U/L (P<0.05) were the long-term warning factors for patients. Multivariate analysis showed that the size of the spleen was an independent factor (P<0.01) to affect the prognosis of the patients who had been warned for 12 months. CONCLUSION: Patients at 12 months warning effect are slower and less easier to get DMR, which has a poor long-term prognosis. The size of the spleen in the patient at warning for 12 months of treatment effect can predict the relatively poor long-term prognosis. For a patient with a 12 months response to the warning, an early replacement therapy is available on the basis of combining other factors..