Process improvement of high aspect ratio nano-gratings based on synchrotron x-ray.

To achieve better structural accuracy and aspect ratio, nano-gratings with a vertical angle close to 90° and a depth-to-width ratio of about 8 were prepared by synchrotron radiation. The optimal exposure dose and development time were determined to be 0.006 (A·h) and 6 min, respectively, by observing the surface loss and roughness of the gratings with slit widths of 150 nm and 250 nm under different conditions. To obtain the desired rectangular grating structure, the experimental conditions were optimized with the help of controlled variables experimental method. With the mask-to-photoresist pitch and the development and drying temperatures of 20µm and 23 °C, the optimized depth-to-width ratio of the nano-gratings with a slit width of 250 nm can reach 8.28. The cone angle can reach 88.4°. The aspect ratio of the nano-gratings with a slit width of 150 nm is 7.18, and its cone angle is 87.1°.

Design, Manufacture and Test of Piezoelectric Cantilever-Beam Energy Harvesters with Hollow Structures.

This article presents a single-crystal piezoelectric energy harvester (PEH) with a trapezoidal hollow hole that can obtain high energy density at low frequency. Harvesters with a hollow structure were fabricated through a series of manufacturing processes such as thermocompression bonding, screen printing and laser cutting. Finite element analysis (FEA) and experimental results showed that using low modulus brass instead of stainless steel as the PEH substrate enhances the voltage output of the device, and the hollow design greatly increases the overall stress level and power density. In addition, the developed PEH with a trapezoidal hole obtained the best output performance; when the acceleration, resonance frequency and matched load resistance were 0.5 g, 56.3 Hz and 114 kΩ, respectively, the peak voltage was 17 V and the power density was 2.52 mW/cm3. Meanwhile, compared with the unhollowed device, the peak voltage and maximum power density of the proposed PEH were increased by 30.7% and 24.4%, respectively, and the resonance frequency was reduced by 7%. This study verified the feasibility of the optimized design through simulation and experimental comparison.

Biomechanical comparison of bionic, screw and Endobutton fixation in the treatment of tibiofibular syndesmosis injuries.

BACKGROUND: The two prevalent fixation methods in the treatment of syndesmosis injuries, the rigid screw fixation and flexible Endobutton fixation, are not without issues; thus, we have designed a novel bionic fixation method which combines the features of both rigid and flexible fixations. The aim of this study was to compare the biomechanical properties of the bionic fixation to the screw and Endobutton fixations. METHODS: Six normal fresh-frozen legs from amputation surgery were used. After initial tests of intact syndesmosis, screw, bionic and Endobutton fixations were performed sequentially for each specimen. Axial loading as well as rotation torque were applied, in five different ankle positions: neutral position, dorsiflexion, plantar flexion, varus, and valgus. The displacement of the syndesmosis and the tibial strain were analysed using a biomechanical testing system. RESULTS: Whether receiving axial loading or rotation torque, in most situations (neutral position, dorsiflexion, varus, plantar flexion with low loading, valgus with high loading, internal and external rotation), the bionic group and Endobutton group had comparable displacements, and there was no significant difference among the intact, bionic, and Endobutton groups; whereas the displacements of the screw group were smaller than any of the other three groups. Results of the tibial strain were similar with that of the displacement. CONCLUSIONS: The bionic fixation at least equals the performance of Endobutton fixation; it also allows more physiologic movement of the syndesmosis when compared to the screw fixation and may serve as a viable option for the fixation of the tibiofibular syndesmosis.

[The effect of TFF3 on the proliferation and migration of papillary thyroid carcinoma K1 cell].

OBJECTIVE: To explore the effect on proliferation and invasion of human papillary thyroid carcinoma K1 cells by application of small hairpin RNA (shRNA) silencing TFF3 gene expression. METHOD: Using liposome transfection method, TFF3-shRNA targeting of TFF3 gene will be transient transfected to papillary thyroid carcinama K1 cells, inducing the corresponding gene silencing. The experiment set up blank control group (Con group), negative control group (ConNC group) and interference group (TFF3-shRNA group). The TFF3 protein and mRNA expression were evaluated by RT-PCR, Real time-PCR, immunocytochemistry and Western blot in K1 cells after TFF3-shRNA transfected. CCK-8 method and Scratch test were used to detect the change of proliferation ability and invasion ability respectively. RESULT: (1) The recombinant plasmid Ca # HSH018037-4-HIVmU6 carrying TFF3-shRNA transfected K1 cells successfully. (2) RT-PCR and Real time-PCR detected the expression of TFF3 mRNA, which was 0.38 ± 0.11 times as many as the blank control group (P < 0.01) after TFF3 gene silenced. But the negative control group was 1.082 times of blank control group (P > 0.05). (3) Western blot show that after TFF3 gene silence induced TFF3 protein expression levels have decreased 59.5% (P < 0.01), The difference was statistically significant compared with the blank control group. (4) Cell scratch detects K1 cell invasion ability. The invasion ability of K1 cells in interference group (TFF3-shRNA group) reduced. The scratch width significantly decreased 57.1% than blank control group (P < 0.01). (5) CCK-8 kit detect cell proliferation ability. K1 cells grow significantly slower in the interference group (TFF3-shRNA group) than the blank control group through the analysis of the growth curve (P < 0.01). In the interference group (TFF3-shRNA group) proliferation inhibition rate of K1 cells at 6 h, 12 h, 24 h and 36 h, 48 h are 16.6%, 26.6%, 33.6%, 33.8%, 35.0% respectively. Compared with negative control group, proliferation ability of K1 cell decreased significantly. CONCLUSION: Silenced TFF3 gene can cause the degradation of mRNA, reduce the protein translation , and inhibit the invasion and proliferation ability of K1 cell.

Gray level entropy matrix is a superior predictor than multiplex ELISA in the detection of reactive stroma and metastatic potential of high-grade prostatic adenocarcinoma.

Recent reports have indicated that not only the primary glandular tissue but also the surrounding stromal tissue plays an active role in the progression of carcinoma. Such is true for cancer tissues arising in the prostate. However, the precise role of stromal tissue in benign prostatic hyperplasia (BPH) and prostate adenocarcinoma is not well described. We undertook this current investigation to examine the changes in orientation of the extracellular matrix and correlate with prostatic cancer progression. We used a novel form of image analysis called gray level entropy matrix (GLEM) texture analysis to evaluate morphometric changes in stromal tissues. We used normal prostatic tissue obtained from cadaveric specimen and compared with BPH, prostatic intraepithelium neoplastic, hormone responsive prostatic adenocarcinoma and castration-resistant prostatic adenocarcinoma tissues. GLEM showed higher entropy in disease-resistant prostatic tissues, compared with benign forms of all spectra of pathologically diagnosed prostatic tissues (P < 0.05, ANOVA, between groups). Higher entropy is reflective of the disorganized morphological organization of the stroma, possibly reflecting the reactive matrix. In contrast, ELISA revealed that although individually correlated with the progressive stages of benign and carcinomatous prostatic tissues and trend correlation between groups, intergroup comparisons failed to arrive at statistical significance of comparisons between markers of neovasculogenesis, vascular endothelial growth factor, epithelial-mesenchymal transition (beta1-integrin, E-cadherin, MMP3) and osteogenic metastasis (RANKL and osteoprotegerin). The results of our study demonstrate the potential of GLEM entropy of gray level pixel in providing quasiquantitative estimate of a reactive stroma in advance stages of prostatic adenocarcinoma and thus can be routinely used in clinical decision making.

A novel technology: percutaneous injection of fibrin glue as a treatment for frontal sinus cerebrospinal fluid rhinorrhea.

In this study, we examined the effectiveness of percutaneous injected fibrin glue as a treatment for frontal sinus cerebrospinal fluid (CSF) rhinorrhea in a series of 4 cases. All 4 patients had fracture in the posterior wall of the frontal sinus. The anterior wall of the frontal sinus was punctured following high-resolution computed tomography imaging. In 3 out of 4 patients with defective skull due to prior frontal craniotomy, direct percutaneous puncture of the frontal sinus was used. Fibrin glue was injected to close the fistula and to seal the rhinorrhea. Surgery procedures lasted for 15-35 minutes (average 27.6 min). Rhinorrhea was stopped in all patients after the surgery, with no recurrence at a 10-month follow-up visit. In 1 case, the glue was expelled by coughing at 2 days after the surgery but was completely stopped with no recurrence after a second attempt. One patient with no recurrence at a 10-month follow-up died of tumor relapse at 12 months. In summary, fibrin glue could be used as a novel treatment for frontal sinus CSF rhinorrhea.

Evaluating glymphatic pathway function utilizing clinically relevant intrathecal infusion of CSF tracer.

BACKGROUND: Neurodegenerative diseases such as Alzheimer's are associated with the aggregation of endogenous peptides and proteins that contribute to neuronal dysfunction and loss. The glymphatic system, a brain-wide perivascular pathway along which cerebrospinal fluid (CSF) and interstitial fluid (ISF) rapidly exchange, has recently been identified as a key contributor to the clearance of interstitial solutes from the brain, including amyloid ß. These findings suggest that measuring changes in glymphatic pathway function may be an important prognostic for evaluating neurodegenerative disease susceptibility or progression. However, no clinically acceptable approach to evaluate glymphatic pathway function in humans has yet been developed. METHODS: Time-sequenced ex vivo fluorescence imaging of coronal rat and mouse brain slices was performed at 30-180 min following intrathecal infusion of CSF tracer (Texas Red- dextran-3, MW 3 kD; FITC- dextran-500, MW 500 kD) into the cisterna magna or lumbar spine. Tracer influx into different brain regions (cortex, white matter, subcortical structures, and hippocampus) in rat was quantified to map the movement of CSF tracer following infusion along both routes, and to determine whether glymphatic pathway function could be evaluated after lumbar intrathecal infusion. RESULTS: Following lumbar intrathecal infusions, small molecular weight TR-d3 entered the brain along perivascular pathways and exchanged broadly with the brain ISF, consistent with the initial characterization of the glymphatic pathway in mice. Large molecular weight FITC-d500 remained confined to the perivascular spaces. Lumbar intrathecal infusions exhibited a reduced and delayed peak parenchymal fluorescence intensity compared to intracisternal infusions. CONCLUSION: Lumbar intrathecal contrast delivery is a clinically useful approach that could be used in conjunction with dynamic contrast enhanced MRI nuclear imaging to assess glymphatic pathway function in humans.

'Hit & Run' model of closed-skull traumatic brain injury (TBI) reveals complex patterns of post-traumatic AQP4 dysregulation.

Cerebral edema is a major contributor to morbidity associated with traumatic brain injury (TBI). The methods involved in most rodent models of TBI, including head fixation, opening of the skull, and prolonged anesthesia, likely alter TBI development and reduce secondary injury. We report the development of a closed-skull model of murine TBI, which minimizes time of anesthesia, allows the monitoring of intracranial pressure (ICP), and can be modulated to produce mild and moderate grade TBI. In this model, we characterized changes in aquaporin-4 (AQP4) expression and localization after mild and moderate TBI. We found that global AQP4 expression after TBI was generally increased; however, analysis of AQP4 localization revealed that the most prominent effect of TBI on AQP4 was the loss of polarized localization at endfoot processes of reactive astrocytes. This AQP4 dysregulation peaked at 7 days after injury and was largely indistinguishable between mild and moderate grade TBI for the first 2 weeks after injury. Within the same model, blood-brain barrieranalysis of variance permeability, cerebral edema, and ICP largely normalized within 7 days after moderate TBI. These findings suggest that changes in AQP4 expression and localization may not contribute to cerebral edema formation, but rather may represent a compensatory mechanism to facilitate its resolution.

[Role of polymorphonuclear neutrophil apoptosis and expression of Fas and caspase-3 in the systemic inflammatory response syndrome].

OBJECTIVE: To study the role of the polymorphonuclear neutrophil (PMN) apoptosis and expression of Fas and caspase-3 in the systemic inflammatory response syndrome (SIRS). METHODS: Eight acute pancreatitis patients with SIRS, 6 healthy control subjects were enrolled to study apoptosis of PMN in peripheral blood samples, expression of Fas/Fas ligand (FasL) and caspase-3 in the PMN, the levels of serum interleukin-6 (IL-6) and IL-8 were observed. RESULTS: Spontaneous apoptosis was significantly delayed in PMN from the SIRS patients with higher serum IL-6 and IL-8 levels compared with controls (both P<0.01). PMN apoptosis rate in peripheral blood of patients with SIRS was lowered than that of controls (P<0.01). The expressions of Fas and caspase-3 in the peripheral circulating PMN were higher in the controls than those in the SIRS patients (both P<0.01). Serum FasL expression was not found by Western blotting 24 hours after culture of PMN in vitro. CONCLUSION: Peripheral circulating PMN from acute pancreatitis patients with SIRS show delayed apoptosis, decreased expressions of Fas and caspase-3, and prolonged PMN survival may contribute to the development of systemic inflammatory injury characteristic of SIRS.