Modeling the Piezoelectric Cantilever Resonator with Different Width Layers.

The piezoelectric cantilever resonator is used widely in many fields because of its perfect design, easy-to-control process, easy integration with the integrated circuit. The tip displacement and resonance frequency are two important characters of the piezoelectric cantilever resonator and many models are used to characterize them. However, these models are only suitable for the piezoelectric cantilever with the same width layers. To accurately characterize the piezoelectric cantilever resonators with different width layers, a novel model is proposed for predicting the tip displacement and resonance frequency. The results show that the model is in good agreement with the finite element method (FEM) simulation and experiment measurements, the tip displacement error is no more than 6%, the errors of the first, second, and third-order resonance frequency between theoretical values and measured results are 1.63%, 1.18%, and 0.51%, respectively. Finally, a discussion of the tip displacement of the piezoelectric cantilever resonator when the second layer is null, electrode, or silicon oxide (SiO2) is presented, and the utility of the model as a design tool for specifying the tip displacement and resonance frequency is demonstrated. Furthermore, this model can also be extended to characterize the piezoelectric cantilever with n-layer film or piezoelectric doubly clamped beam.

Efficacy and Safety of Renal Sympathetic Denervation on Dogs with Pressure Overload-Induced Heart Failure.

BACKGROUND: In dogs with heart failure (HF) induced by overload pressure, the role of renal sympathetic denervation (RSD) on heart failure and in the renal artery is unclear. Therefore, we investigated the efficacy and safety of RSD in dogs with pressure overload-induced heart failure. METHODS: Twenty mongrel dogs were divided into a sham-operated group, an HF group and an HF + RSD group. In the sham-operated group, the abdominal aorta was located but was not constricted, in the HF group, the abdominal aorta was constricted without RSD, and the HF+RSD group underwent RSD with constriction of the abdominal aorta after 10 weeks. Blood sampling assays, echocardiography, intravascular ultrasound (IVUS) measurement and histopathological examination were performed. RESULTS: Renal sympathetic denervation caused a significant reduction in the levels of noradrenaline (166.62±6.84 vs. 183.48±13.66 pg/ml, P<0.05), plasma renin activity (1.93±0.12 vs. 2.10±0.13 ng/mlh, P<0.05) and B-type natriuretic peptide (71.14±3.86 vs. 83.15±5.73 pg/ml, P<0.05) at eight weeks after RSD in the HF+RSD group. Compared with the HF group at eight weeks, the left ventricular internal dimension at end-diastole and end-systole were lower and the left ventricular ejection fraction was higher (all P<0.05) at eight weeks after RSD in the HF+RSD group. Intravenous ultrasound images showed no changes in the renal artery lumen, and intimal hyperplasia and vascular lumen stenosis were not observed after RSD. CONCLUSIONS: Renal sympathetic denervation could improve cardiac function in dogs with HF induced by pressure overload; RSD had no adverse influence on the renal artery.

Urachus adenocarcinoma mistaken for umbilical incision implant cancer after laparoscopic cholecystectomy: a case report.

Umbilical incision implant cancer after LC is rare. Elective cholecystectomy was planned for a 49 years-old female patient with symptomatic gallstones. The patient underwent transumbilical single-port LC after admission to our hospital. Gallbladder specimens were obtained directly through the umbilical puncture hole, and histopathology suggested chronic cholecystitis. Three months after surgery, the patient experienced painful induration in the umbilicus. We initially considered incision scar hyperplasia complicated with pain, and used drugs to treat it conservatively without taking special treatment measures. Six months after LC, the umbilical induration pain affected her quality of life, and the patient requested surgical resection. Preoperative ultrasonography and abdominal computerized tomography (CT) revealed nodular changes around the umbilicus and no abdominal mass. Local resection of the periumbilical mass was performed, and the pathological confirmation was invasive adenocarcinoma. Subsequently, the patient underwent repeat periumbilical mass enlargement resection. Postoperative pathology showed no cancer at the enlarged resection margin, yet the umbilical center pathology showed invasive adenocarcinoma. The excised pathology was sent to the Sun Yat-sen University Cancer Center for consultation because of the rare nature of the findings associated with the case. After consultation, a diagnosis of umbilical urachus adenocarcinoma was confirmed based on pathological morphology, immunohistochemistry, and the specific anatomical location of the tumor. This case report shown that when there is a persistent mass induration in the navel after LC surgery, the possibility of incision tumor should be considered, rather than simply excluding the possibility of a cancer based on a non-cancer medical history.

Stress-induced interaction between p38 MAPK and HSP70.

p38 MAPK, one of the four MAPK subfamilies in mammalian cells, is activated by environmental stresses and pro-inflammatory cytokines, playing fundamental roles in many biological processes. Despite all that is known on the structure and functions of p38, many questions still exist. The coupling of activation and nuclear translocation represents an important aspect of p38 signaling. In our effort in exploring the potential chaperone for p38 translocation, we performed an endogenous pull-down assay and identified HSP70 as a potential interacting protein of p38. We confirmed the interaction between p38 and HSP70 in vitro and in vivo, and identified their interaction domains. We also showed stress-induced nuclear co-localization of these two proteins. Our preliminary result indicated that HSP70 was related to the phosphorylation of MK2, a specific nuclear downstream target of p38, suggesting HSP70 is a potential chaperone for the nuclear translocation of p38.

Modeling and Parameter Sensitivity Improvement in ΔE-Effect Magnetic Sensor Based on Mode Localization Effect.

A mode-localized ΔE-effect magnetic sensor model is established theoretically and numerically. Based on the designed weakly coupled resonators with multi-layer film structure, it is investigated how the ΔE-effect of the magnetostrictive film under the external magnetic field causes the stiffness perturbation of the coupled resonators to induce the mode localization effect. Using the amplitude ratio (AR) as the output in the mode-localized ΔE-effect magnetic sensor can improve the relative sensitivity by three orders of magnitude compared with the traditional frequency output, which has been verified by simulations based on the finite element method (FEM). In addition, the effects of material properties and geometric dimensions on sensor performance parameters, such as sensitivity, linear range, and static operating point are also analyzed and studied in detail, providing the theoretical basis for the design and optimization of the mode-localized ΔE-effect magnetic sensor in different application scenarios. By reasonably optimizing the key parameters of the weekly coupled resonators, a mode-localized ΔE-effect magnetic sensor with the sensitivity of 18 AR/mT and a linear range of 0.8 mT can be achieved.

Expression of cyclin D1 in small cell lymphoma and its clinical implications.

OBJECTIVE: To observe the expression of cyclin D1 and explore its clinical significance in small cell lymphoma. METHODS: Immunohistochemical method was used to detect the expression of CD20, CD45RO and cyclin D1 in 31 formalin- fixed and paraffin-embedded tissue samples of human small cell lymphomas. RESULTS: Twenty-eight cases were categorized into B cell lymphoma and 3 into T cell lymphoma. Only 5 cases of B cell lymphoma had cyclin D1 expression (17.86%) that did not significantly differ between nodal and extranodal lymphomas (P>0.05), indicating the presence of mantle cell lymphoma. CONCLUSION: The overexpression of cyclin D1 is a highly characteristic and specific indicator that discriminates mantle cell lymphoma from other small cell lymphomas, and this protein may offer critial guidance for therapeutic protocol and prognostic estimation.