A GHz Silicon-Based Width Extensional Mode MEMS Resonator with Q over 10,000.

This work presents a silicon-based capacitively transduced width extensional mode (WEM) MEMS rectangular plate resonator with quality factor (Q) of over 10,000 at a frequency of greater than 1 GHz. The Q value, determined by various loss mechanisms, was analyzed and quantified via numerical calculation and simulation. The energy loss of high order WEMs is dominated by anchor loss and phonon-phonon interaction dissipation (PPID). High-order resonators possess high effective stiffness, resulting in large motional impedance. To suppress anchor loss and reduce motional impedance, a novel combined tether was designed and comprehensively optimized. The resonators were batch fabricated based on a reliable and simple silicon-on-insulator (SOI)-based fabrication process. The combined tether experimentally contributes to low anchor loss and motional impedance. Especially in the 4th WEM, the resonator with a resonance frequency of 1.1 GHz and a Q of 10,920 was demonstrated, corresponding to the promising f × Q product of 1.2 × 1013. By using combined tether, the motional impedance decreases by 33% and 20% in 3rd and 4th modes, respectively. The WEM resonator proposed in this work has potential application for high-frequency wireless communication systems.

High Quality-Factor and Spectrum-Clean AlN Lamb-Wave Resonators with Optimized Lateral Reflection Boundary Conditions and Transducer Design.

This paper presents a high quality-factor (Q) and spectrum-clean AlN Lamb-wave resonator (LWR). The width of its lateral reflection boundary was optimized to weaken the transverse modes' coupling and wave guiding, and then to improve the LWR's Q value and spectral purity, which was verified by finite element analysis and experimental characterization. In addition, the series resonance quality factor (Qs) value of the interdigitated (IDT)-Ground LWR is similar to that of the IDT-Floating LWR, but its parallel resonance quality factor (Qp) is nearly doubled, due to the reduction of the electrical loss induced by its static capacitance (C0). The measured results show that the designed LWR with optimized boundary reflection conditions and IDT-Ground structure exhibit Qs and Qp values as high as 4019.8 and 839.5 at 401.2 MHz and 402.9 MHz, respectively, meanwhile, it has good spectral purity. Moreover, the influence of the metal ratio and material of the LWR's IDT electrodes on the device's performance was also studied by theoretical analysis and experimental verification.

Batch Fabrication of Wear-Resistant and Conductive Probe with PtSi Tip.

This paper presents a simple and reliable routine for batch fabrication of wear-resistant and conductive probe with a PtSi tip. The fabrication process is based on inductively coupled plasma (ICP) etching, metal evaporation, and annealing. Si tips with curvature radii less than 10 nm were produced with good wafer-level uniformity using isotropic etching and thermal oxygen sharpening. The surface roughness of the etched tip post was reduced by optimized isotropic etching. The dependence of the platinum silicide morphology on annealing conditions were also systematically investigated, and conductive and wear-resistant probes with PtSi tips of curvature radii less than 30 nm were batch fabricated and applied for scanning piezoelectric samples.

Dominant Loss Mechanisms of Whispering Gallery Mode RF-MEMS Resonators with Wide Frequency Coverage.

This work investigates the dominant energy dissipations of the multi-frequency whispering gallery mode (WGM) resonators to provide an insight into the loss mechanisms of the devices. An extensive theory for each loss source was established and experimentally testified. The squeezed film damping (SFD) is a major loss for all the WGMs at atmosphere, which is distinguished from traditional bulk acoustic wave (BAW) resonators where the high-order modes suffer less from the air damping. In vacuum, the SFD is negligible, and the frequency-dependent Akhiezer damping (AKE) has significant effects on different order modes. For low-order WGMs, the AKE is limited, and the anchor loss behaves as the dominant loss. For high-order modes with an extended nodal region, the anchor loss is reduced, and the AKE determines the Q values. Substantial Q enhancements over four times and an excellent f × Q product up to 6.36 × 1013 at 7 K were achieved.

Batch Fabrication of Silicon Nanometer Tip Using Isotropic Inductively Coupled Plasma Etching.

This work reports a batch fabrication process for silicon nanometer tip based on isotropic inductively coupled plasma (ICP) etching technology. The silicon tips with nanometer apex and small surface roughness are produced at wafer-level with good etching homogeneity and repeatability. An ICP etching routine is developed to make silicon tips with apex radius less than 5 nm, aspect ratio greater than 5 at a tip height of 200 nm, and tip height more than 10 µm, and high fabrication yield is achieved by mask compensation and precisely controlling lateral etch depth, which is significant for large-scale manufacturing.

Enhanced Binding Efficiency of Microcantilever Biosensor for the Detection of Yersinia.

A novel microcantilever sensor was batch fabricated for Yersinia detection. The microcantilever surface modification method was optimized by introducing a secondary antibody to increase the number of binding sites. A novel microfluidic platform was designed and fabricated successfully. A 30 µL solution could fully react with the microcantilever surface. Those routines enhanced the binding efficiency between the target and receptor on the microcantilever. With this novel designed microfluidic platform, the specific adsorption of 107 Yersinia on the beam surface with modified F1 antibody was significantly enhanced.

Triptolide sensitizes cisplatin-resistant human epithelial ovarian cancer by inhibiting the phosphorylation of AKT.

Advanced and chemotherapy-resistant ovarian cancer causes high mortality of ovarian cancer, and it is important to find safe and effective drugs to reduce the chemotherapeutic resistance of ovarian cancer. In our study, we attempted to clarify the resistance mechanisms of SKOV3/DDP cells in vitro and evaluated the sensitization to triptolide (TPL) in vivo. Our results indicated that the overexpression of AKT and p-AKT greatly enhanced the cisplatin (DDP) tolerance of SKOV3/DDP, and the combination of DDP+TPL had a significant tumour inhibition effect compared to DDP treatment (p<0.05), via reducing the expressions of p-PI3K, p-Akt, Survivin, VEGF and MMP-2, and the increase of Caspase-3. Collectively, these results suggest that the synergistic anticancer effect of TPL and DDP warrants their potential clinical applications in further.

A high accuracy cantilever array sensor for early liver cancer diagnosis.

Early liver cancer diagnosis has clinical significance in treating cancer. Joint detection of multiple biomarkers has been considered as an effective and reliable method for early cancer diagnosis. In this work, a novel biosensor based on microcantilever array was batch-fabricated for multiple liver cancer biomarkers detection with high sensitivity, high accuracy, high throughput, and high specification. A micro-cavity was designed in the free end of the cantilever for local reaction between antibody and antigen, which can dramatically reduce the effect of adsorption-induced stiffness coefficient k variation. Furthermore,the pillar arrays in the micro-cavity were designed for increasing detection upper limit. A linear relationship between the relative frequency shift and the antigen concentration was observed for three liver cancer biomarkers, alpha-fetoprotein (AFP), γ-glutamyltranspeptidase II (GGT-2), and hepatocyte growth factor (HGF). Slight cross-reaction response to different antigens ensures high specificity of the sensor. These features will promote clinical application of the cantilever sensors in early cancer diagnosis.

[Analysis of carbapenems by hydrophilic interaction chromatography and its application].

A hydrophilic interaction chromatographic (HILIC) method has been developed for the determination of the four carbapenems in human urine and tap water. The parameters including acetonitrile amount, buffer concentration and pH on the retention behavior of the four carbapenem antibiotics on an XAmide column were explored and the possible HILIC retention mechanism was proposed. Good linearities were obtained over the mass concentration ranges of 0.1-250 mg/L for biapenem, doripenem and ertapenem with correlation coefficients (R2) = 0.999 9 and while it was 0.5-250 mg/L with R2 = 0.999 8 for meropenem. The limits of quantification (LOQs) of all carbapenems were 0.1-0.5 mg/L. The spiked recoveries were within 100.4%-111.9% (RSD < 1%) for urine samples and 79.6%-107.4% (RSD < 5%) for tap water samples all at the spiked levels of 5 mg/L and 25 mg/L. The proposed method is accurate, sensitive, simple and suitable for the determination of the four carbapenems in human urine samples and tap water samples.

[Effect of compound qizhu granule on cellular immunity of chronic hepatitis B patients].

OBJECTIVE: To explore the effect of compound qizhu granule (CQG) on cellular immunity of chronic hepatitis B (CHB) patients. METHODS: Totally 103 CHB patients treated with lamivudin (LAM) for 6 months, who had partial virological response (HBeAg positive) were randomly assigned to two groups, 50 in the treatment group and 53 in the control group. All patients took LAM 100 mg (once a day) plus ADV 10 mg (once a day). Patients in the treatment group additionally took CQG, one dose per day. After one-year treatment hepatitis B virus (HBV) DNA negative rates, HBeAg seroconversion, levels of HBV specific cytotoxic T lymphocyte (CTL), non-specific CTL and natural killing (NK) cells were compared between the two groups. RESULTS: After 1-year treatment, HBV DNA negative rate of the treatment group was 88: 0% in 44 cases, slightly higher than that of the control group (41 cases, 77.4%), but with no statistical difference (P >0.05). HBeAg seroconversion of the treatment group was 32.0% in 16 cases, higher than that of the control group (8 cases, 15.1%), with statistical difference (P <0.05). Levels of HBV specific CTL (0.79%±0. 07%), non-specific CTL (19.4%±1.8%) and NK cells (14. 1%± 1.5%) of the treatment group were higher than those of the control group (0.58% ± 0.08%, 17.5% ± 1.7%, and 11.1%±1.5%, respectively; allP <0.01). CONCLUSION: Treating CHB patients with partial virological response by ADV plus CQG could improve specific and non-specific cellular immunity, thereby elevating HBeAg seroconversion rate.

[Influence of non-sodium restricted diet with diuretics on plasma rennin, renal blood flow and in patients with cirrhotic ascites].

OBJECTIVE: To explore influence of sodium restricted diet and non-sodium restricted diet on plasma rennin (PRA), angiotensin II (All), ALD, renal blood flow (RBF) and subside of ascites in patients with cirrhotic ascites. METHODS: Eighty cases of hepatitis B with cirrhotic ascites were randomly divided into sodium restricted diet group and non-sodium restricted diet group. 39 cases were in non-sodium restricted diet group, taking sodium chloride 6500-8000 mg daily; 41 cases were in sodium restricted diet group, taking sodium chloride 5000 mg daily. Both groups received diuretics furosemide and spironolactone. Blood sodium, urine sodium, PRA, AII, ALD, RBF ascites subsiding were compared after treatment. RESULTS: In non-sodium restricted diet group, blood sodium and urine sodium increased 10 days after treatment compared with those before treatment, and compared with those of sodium restricted diet group 10 days after treatment, P <0. 01. RBF increased compared with that before treatment, and compared with that of sodium restricted diet group 10 days after treatment, P < 0. 01. Renal damage induced by low blood sodium after treatment was less in non-sodium restricted diet group than that in sodium restricted diet group, P <0. 05. Ascites disappearance upon discharge was more in sodium restricted diet group than that in non-sodium restricted diet group, P <0. 01. Time of ascites disappearance was shorter in non-sodium restricted diet group than that in sodium restricted diet group, P < 0. 01. CONCLUSION: Compared with sodium restricted diet, while using diuretics of both groups, non-sodium restricted diet can increase level of blood sodium, thus increasing excretion of urine sodium and diuretic effect. It can also decrease levels of PRA, AII and ALD, increase renal blood flow and prevent renal damage induced by low blood sodium and facilitate subsiding of ascites.

[Relationship between effect of lamivudine in the treatment of cirrhotic patients with uncompensated hepatitis B with HBV genotypes and cytotoxic T lymphocyte].

OBJECTIVE: To explore relationship between effect of Lamivudine in the treatment of cirrhotic patients with uncompensated hepatitis B with hepatitis B virus (HBV)genotypes and HBV specific cytotoxic T lymphocytes (CTL). METHODS: 80 cases of uncompensated cirrhotic hepatitis B (40 cases with genotype B and 40 with genotype C), HBV DNA positive, HBeAg positive and human leukocyte antigen (HLA)-A2 positive,were treated with Lamivudine 100 mg/d, one year later, its effect and relationship with HBV genotypes and HBV specific CTL were observed. RESULTS: HBV DNA turned negative:40 cases with genotype B turned negative (100%). In the 9th and 10th month of treatment, there was one case with genotype C had YMDD variation respectively and Adefovir dipivoxil was used for treatment, of the rest 38 cases, HBV DNA of 26 cases (68.42%) turned negative,HBV DNA negative rate of patients with genotype is lower than that of patients with genotype B, chi2 = 14.91, P < 0.01. HBeAg turned negative: 18 cases with genotype B (45%) turned negative, more than that of patients with genotype C (7 cases, 18.42%), chi2 = 6.32, P < 0.05. Peripheral blood HBV specific CTL level: before treatment, it was (0.33 +/- 0.03)% of patients with genotype B,higher than that of patients with genotype C [(0.11 +/- 0.02)%], t = 8.12, P < 0.001. 1 year after treatment: it was (0.44 +/- 0.04)% of patients with genotype B, higher than that before treatment, t = 4.01, P < 0.001, it was also higher than that of patients with genotype C 1 year after treatment [(0.23 +/- 0.03)%], t = 5.63, P < 0.01, alanine amino-transferase (ALT) returned to normal: 38 cases with genotype B (95%) returned to normal, more than that of patients with genotype C (28 cases, 73.68%), X2 = 6.79, P < 0.01. CONCLUSION: Effect of Lamivudinein the treatment of cirrhotic patients with uncompensated hepatitis B is better in patients with genotype B than patients with genotype C, its mechanism may be related to lower level of HBV specific CTL in patients with genotype C than patients with genotype B.

[Relationship between serum HBV DNA level and follicular helper T lymphocyte in patients with chronic hepatitis B and its significance].

OBJECTIVE: To explore relationship between HBV DNA level and peripheral blood follicular helper T lymphocyte (Tfh) in patients with chronic hepatitis B (CHB) and its significance. METHODS: HBV DNA levels of 179 cases of CHB patients with positive HBV DNA, positive HBeAg and positive human leukocyte antigen(HLA)-A2 were tested with real time fluorescent quantitative PCR. Tfh and HBV specific CTL were tested with flow cytometry. IL-21 was also tested. 179 cases of CHB patients were divided into group A and group B based on HBV DNA levels, 86 cases in group A, HBV DNA levels were 10(4)-10(5) copies/ml, 93 cases in group B, HBV DNA levels were 10(6)-10(7) copies/ml. Above testing indexes of the two groups were compared. RESULTS: HBV DNA levels of group A were (4.85 +/- 0.37) log10 copies/ml, HBV DNA levels of group B were (6.83 +/- 0.31 ) log10 copies/ml, t = 27.31, P < 0. 001; Tfh of group A was (5.96 +/- 1.59)%, higher than that of group B (3.71 +/- 2.15)%, t = 4.92, P < 0.01; IL-21 of group A was (42.61 +/- 15.11)ng/L, higher than that of group B (14.91 +/- 3.15) ng/L, t = 8.62, P < 0.01; HBV specific CTL of group A was (0.36 +/- 0.08)%, higher than that of group B (0.18 +/- 0.06)%, t = 19.99, P < 0.001. CONCLUSION: Serum HBV DNA level of CHB patients is related to the level of peripheral blood Tfh level: patients with low HBV DNA level have high Tfh level, high IL-21 level and high HBV specific CTL level. Patients with high HBV DNA level have low Tfh level, low IL-21 level and low HBV specific CTL level. The mechanism of baseline HBV DNA level affecting anti-viral therapy may be related to Tfh level.

[Study on effects of kurarinol combined with glycyrrhizic acid on cellular immunity of patients with chronic hepatitis B].

OBJECTIVE: To explore effects of kurarinol combined with Diammonium Glycyrrhizinate on specific cellular immunity of patients with chronic hepatitis B (CHB). METHODS: Sixty-three CHB patients were randomly divided into two groups, 32 cases in group of kurarinol combined with Diammonium Glycyrrhizinate group (combined therapy group) were treated with 600 mg kurarinol glucose injection intravenously, once a day for one month, then 200 mg kurarinol capsule was used orally, three times a day for two months. 150 mg Diammonium Glycyrrhizinate for Injection was added to 250 ml 10% glucose injection for intravenous drip, once a day for one month, then 150 mg Diammonium Glycyrrhizinate capsule was used orally, three times a day for two months; 31 case in kurarinol group (single drug group) only used kurarinol, methods and dosage were the same as those of treatment group. HBV specific CTL, T cell subgroups, change of Th1 and Th2 level, HBV-DNA and HBeAg negative rate of the two groups were compared. RESULTS: Three months after treatment, HBV specific CTL, CD4 + and Th1 of combined therapy group were higher than those before treatment, and higher than those of single drug group after treatment (P < 0.01). CONCLUSION: HBV-DNA and HBeAg negative rate between the two groups had no statistic significance (P > 0.05). CONCLUSION: Kurarinol combined with Diammonium Glycyrrhizinate can further increase HBV specific CTL, CD4+ and Th1 level of CHB patients.

Effect of oxymatrine on specific cytotoxic T lymphocyte surface programmed death receptor-1 expression in patients with chronic hepatitis B.

BACKGROUND: Oxymatrine has certain antiviral effects in the treatment of chronic hepatitis B (CHB), but its exact mechanism is unclear. The objective of the present study was to explore oxymatrine's antiviral mechanism by studying its effect on the hepatitis B virus (HBV) specific cytotoxic T lymphocyte (CTL) surface programmed death receptor-1 (PD-1) expression in CHB patients. METHODS: Sixty-five CHB patients who had HBV DNA(3)10(4) copies/ml, positive HBeAg, positive human leukocyte antigen (HLA)-A2, alanine aminotransferase (ALT) > 2 x upper limit of normal value (ULN) were randomly divided into two groups: treatment group (n = 33), treated with an intravenous infusion of 600 mg oxymatrine in glucose solution once a day for a month, then with a 200 mg oxymatrine oral capsule three times a day, and a 200 mg silibin meglumine tablet three times a day; control group (n = 32) patients were treated only with silibin meglumine tablet, method and dosage were the same as those of treatment group. Three months later, peripheral blood HBV-specific CTL surface PD-1 expression, HBV-specific CTL level, HBV DNA, HBeAg, and results of liver function tests were analyzed and compared. RESULTS: Three months post-treatment, in the treatment group, peripheral blood HBV-specific CTL surface PD-1 expression ((19.42 ± 15.94)%) decreased significantly compared to the pretreatment level ((31.30 ± 24.06)%; P < 0.05), and decreased significantly compared to that of control group three months after treatment ((29.45 ± 21.62)%; P < 0.05). HBV-specific CTL level ((0.42 ± 0.07)%) significantly increased compared with the pretreatment ((0.29 ± 0.15)%; P < 0.01), and the control group posttreatment level was (0.31 ± 0.15)% (P < 0.05). HBV DNA level in 11 cases became negative (HBV DNA < 500 copies/ml, 33.33%), which was higher than that of the control group after treatment (two cases, 6.25%; χ(2) = 7.45, P < 0.01), HBeAg of nine cases turned negative (27.27%), which was higher than that of the control group after treatment (one case, 3.13%; χ(2) = 7.27, P < 0.01). CONCLUSION: Oxymatrine could downregulate peripheral blood HBV-specific CTL surface PD-1 expression in CHB patients, increase HBV-specific CTL level, which may be one of the possible mechanisms by which oxymatrine clears or inhibits HBV in CHB patients.

[Effect of kurarinol on peripheral blood CTL surface PD-1 expression of patients with chronic hepatitis B].

OBJECTIVE: To explore the anti-viral mechanism of kurarinol through studying its influence on cytotoxic T lymphocyte (CTL) surface program death receptor-1 (PD-1) expression of patients with chronic hepatitis B (CHB). METHODS: 69 cases of CHB, HBV DNA > or = 10(4) copies/ml, HBeAg positive, human leukocyte antigen (HLA)-A2 positive, alanine aminotransferase (ALT) > 2 x upper limit of normal value(ULN).69 cases were randomly divided into two groups:34 cases in treatment group,600 mg of kurarinol glucose injection was used for intravenous dripping, once a day, one month later, 200 mg of kurarinol capsule was used orally,three times a day and 200 mg of silybin meglumine tablet was used orally, three times a day. 35 cases in control group, only silibin meglumine tablet was used, method and dosage were the same as those of treatment group. Three months later, their peripheral blood HBV specific CTL surface PD-1 expression, non-specific CTL surface PD-1 expression and level of HBV specific CTL,HBV DNA and HBeAg negative rate and liver functions were analyzed and compared. RESULTS: 3 months after treatment, peripheral blood HBV specific CTL surface PD-1 expression of the treatment group decreased compared with that before treatment (t = 2.39, P < 0.05), it also decreased compared with that of the control group 3 months after treatment (t = 2.26, P < 0.05), HBV specific CTL increased compared with that before treatment( t = 3.01, P < 0.01), it also increased compared with that of the control group after treatment (t = 2.65, P < 0.05). There was no significant difference of non-specific CTL surface PD-1 expression compared with that before treatment (P > 0.05), and there was no significant difference compared with that of the control group after treatment (P > 0.05). HBV DNA of 11 cases (32.5%) turned negative ( HBV DNA < 500 copies/ ml), higher than that of the control group after treatment (2 cases, 5.71%) chi2 = 7.99, P < 0.01, HBeAg of 9 cases (26.47%) turned negative, higher than that of the control group after treatment (1 case, 2.86%), chi2 = 7.75, P < 0.01. CONCLUSION: Kurarinol can increase level of HBV specific CTL by down-regulating peripheral blood HBV specific CTL surface PD-1 expression of CHB patients, which may be one of the possible mechanisms that kurarinol can remove or inhibit HBV of CHB patients.

[Influence of Kurarinol on specific and non-specific cell immunity in patients with chronic hepatitis B].

OBJECTIVE: To explore influence of Kurarinol on specific and non-specific cell immunity in patients with chronic hepatitis B. METHODS: 74 cases of CHB were randomly divided into two groups, 36 cases in treatment group, treated with 600 mg Kurarinol glucose injection, IV, once a day. After one month, Kurarinol capsule was used orally, three times a day for 2 months, 200 mg Silybin Meglumine Tablets orally, three times a day for 3 months. 38 cases in control group, only Silybin Meglumine Tablets was used, method and dosage were the same as treatment group. Compare HBV specific CTL, non-specific CTL, sub-group of T cells, changes of Th1 and Th2, negative conversion rate of HBV DNA and HBeAg of the two groups. RESULTS: In treatment group, 3 months after treatment with Kurarinol, HBV specific CTL is higher than that before treatment (P < 0.01), it is also higher than that of control after treatment, P < 0.05) . Non-specific CTL is higher than that before treatment (P < 0.05), it is also higher than that of control after treatment (P < 0.01). CD4 is higher than that before treatment (P <0.05), it is also higher than that of control after treatment (P < 0.01), Thl is higher than that before treatment (P < 0.05), it is also higher than that of control after treatment (P < 0.01) . Negative conversion of HBV DNA and HBeAg is higher than that of control (P < 0.01). CONCLUSION: Kurarinol can improve specific and non-specific cell immunity in patients with CHB. It is one of the mechanisms that Kurarinol can clear or inhibit HBV of patients with CHB.