Chemical Etching of Silicon Assisted by Graphene Oxide in an HF–HNO₃ Solution and Its Catalytic Mechanism

Chemical etching of silicon assisted by various types of carbon materials is drawing much attention for the fabrication of silicon micro/nanostructures. We developed a method of chemical etching of silicon that utilizes graphene oxide (GO) sheets to promote the etching reaction in a hydrofluoric acid–nitric acid (HF–HNO₃) etchant. By using an optimized composition of the HF–HNO₃ etchant, the etching rate under the GO sheets was 100 times faster than that of our HF–H₂O₂ system used in a previous report. Kinetic analyses showed that the activation energy of the etching reaction was almost the same at both the bare silicon and GO-covered areas. We propose that adsorption sites for the reactant in the GO sheets enhance the reaction frequency, leading to a deeper etching in the GO areas than the bare areas. Furthermore, GO sheets with more defects were found to have higher catalytic activities. This suggests that defects in the GO sheets function as adsorption sites for the reactant, thereby enhancing the etching rate under the sheets

Formation of submicron-sized silica patterns on flexible polymer substrates based on vacuum ultraviolet photooxidation

Formation of precise and high-resolution silica micropatterns on polymer substrates is of importance in surface structuring for flexible device fabrication of optics, microelectronic, and biotechnology. To achieve that, substrates modified with affinity-patterns serve as a strategy for site-selective deposition. In the present paper, vacuum ultraviolet (VUV) treatment is utilized to achieve spatially-controlled surface functionalization on a cyclo-olefin polymer (COP) substrate. An organosilane, 2, 4, 6, 8-tetramethylcyclotetrasiloxane (TMCTS), preferentially deposits on the functionalized regions. Well-defined patterns of TMCTS are formed with a minimum feature of ∼500 nm. The secondary VUV/(O)-treatment converts TMCTS into SiOx, meanwhile etches the bare COP surface, forming patterned SiOx/COP microstructures with an average height of ∼150 nm. The resulting SiOx patterns retain a good copy of TMCTS patterns, which are also consistent with the patterns of photomask used in polymer affinity-patterning. The high quality SiOx patterns are of interests in microdevice fabrication, and the hydrophilicity contrast and adjustable heights reveal their potential application as a “stamp” for microcontact printing (μCP) techniques

Fundamental and higher eigenmodes of qPlus sensors with a long probe for vertical-lateral bimodal atomic force microscopy

The detection of vertical and lateral forces at the nanoscale by atomic force microscopy (AFM) reveals various mechanical properties on surfaces. The qPlus sensor is a widely used force sensor, which is built from a quartz tuning fork (QTF) and a sharpened metal probe, capable of high-resolution imaging in viscous liquids such as lubricant oils. Although a simultaneous detection technique of vertical and lateral forces by using a qPlus sensor is required in the field of nanotribology, it has still been difficult because the torsional oscillations of QTFs cannot be detected. In this paper, we propose a method to simultaneously detect vertical and lateral force components by using a qPlus sensor with a long probe. The first three eigenmodes of the qPlus sensor with a long probe are theoretically studied by solving a set of equations of motion for the QTF prong and probe. The calculation results were in good agreement with the experimental results. It was found that the tip oscillates laterally in the second and third modes. Finally, we performed friction anisotropy measurements on a polymer film by using a bimodal AFM utilizing the qPlus sensor with a long probe to confirm the lateral force detection

Prospective randomized study for optimal insulin therapy in type 2 diabetic patients with secondary failure

<p>Abstract</p> <p>Background</p> <p>The large clinical trials proved that Basal-Bolus (BB) insulin therapy was effective in the prevention of diabetic complications and their progression. However, BB therapy needs multiple insulin injections per a day. In this regard, a biphasic insulin analogue needs only twice-daily injections, and is able to correct postprandial hyperglycemia. Therefore it may achieve the blood glucose control as same as that of BB therapy and prevent the diabetic complications including macroangiopathy.</p> <p>Methods</p> <p>In PROBE (Prospective, Randomized, Open, Blinded-Endpoint) design, forty-two type 2 diabetic patients (male: 73.8%, median(inter quartile range) age: 64.5(56.8~71.0)years) with secondary failure of sulfonylurea (SU) were randomly assigned to BB therapy with a thrice-daily insulin aspart and once-daily basal insulin (BB group) or to conventional therapy with a twice-daily biphasic insulin analogue (30 Mix group), and were followed up for 6 months to compare changes in HbA1c, daily glycemic profile, intima-media thickness (IMT) of carotid artery, adiponectin levels, amounts of insulin used, and QOL between the two groups.</p> <p>Results</p> <p>After 6 months, HbA1c was significantly reduced in both groups compared to baseline (30 Mix; 9.3(8.1~11.3) → 7.4(6.9~8.7)%, p < 0.01, vs BB;8.9(7.7~10.0) → 6.9(6.2~7.3)%, p < 0.01), with no significant difference between the groups in percentage change in HbA1c (30 Mix; -14.7(-32.5~-7.5)% vs BB -17.8(-30.1~-11.1)%, p = 0.32). There was a significant decrease in daily glycemic profile at all points except dinner time in both groups compared to baseline. There was a significant increase in the amount of insulin used in the 30 Mix group after treatment compared to baseline (30 Mix;0.30(0.17~0.44) → 0.39(0.31~0.42) IU/kg, p = 0.01). There was no significant difference in IMT, BMI, QOL or adiponectin levels in either group compared to baseline.</p> <p>Conclusion</p> <p>Both BB and 30 mix group produced comparable reductions in HbA1c in type 2 diabetic patients with secondary failure. There was no significant change in IMT as an indicator of early atherosclerotic changes between the two groups. The basal-bolus insulin therapy may not be necessarily needed if the type 2 diabetic patients have become secondary failure.</p> <p>Trial registration</p> <p>Current Controlled Trials number, NCT00348231</p

CCL2 as a potential therapeutic target for clear cell renal cell carcinoma

We previously reported that the pVHL-atypical PKC-JunB pathway contributed to promotion of cell invasiveness and angiogenesis in clear cell renal cell carcinoma (ccRCC), and we detected chemokine (C-C motif) ligand-2 (CCL2) as one of downstream effectors of JunB. CCL2 plays a critical role in tumorigenesis in other types of cancer, but its role in ccRCC remains unclear. In this study, we investigated the roles and therapeutic potential of CCL2 in ccRCC. Immunohistochemical analysis of CCL2 expression for ccRCC specimens showed that upregulation of CCL2 expression correlated with clinical stage, overall survival, and macrophage infiltration. For functional analysis of CCL2 in ccRCC cells, we generated subclones of WT8 cells that overexpressed CCL2 and subclones 786-O cells in which CCL2 expression was knocked down. Although CCL2 expression did not affect cell proliferation in vitro, CCL2 overexpression enhanced and CCL2 knockdown suppressed tumor growth, angiogenesis, and macrophage infiltration in vivo. We then depleted macrophages from tumor xenografts by administration of clodronate liposomes to confirm the role of macrophages in ccRCC. Depletion of macrophages suppressed tumor growth and angiogenesis. To examine the effect of inhibiting CCL2 activity in ccRCC, we administered CCL2 neutralizing antibody to primary RCC xenografts established from patient surgical specimens. Inhibition of CCL2 activity resulted in significant suppression of tumor growth, angiogenesis, and macrophage infiltration. These results suggest that CCL2 is involved in angiogenesis and macrophage infiltration in ccRCC, and that CCL2 could be a potential therapeutic target for ccRCC

microRNA デ カガク ホウシャセン リョウホウ ノ コウカ オ ヨソクスル

While global microRNA（miRNA）expression patterns of many embryologic, physiologic, and oncogenic processes have been described, description of the role of miRNAs for preoperative chemoradiotherapy（CRT）in rectal cancer is lacking. Our purpose of this study was to define the expression pattern of miRNAs for prediction of response to chemoradiotherapy in rectal cancer. Rectal cancer patients（n＝22）who underwent preoperative CRT（40Gy radiotherapy combined with S-1）were studied. S-1 is a novel oral fluoropyrimidine inhibitory for dihydropyrimidine dehydrogenase and has potent radiosensitizing property. RNA harvested from biopsy specimens of rectal cancer before preoperative CRT was hybridized to miRNA microarrays（８２１genes）. Response to CRT was determined by histopathologic examination（Japanese Society for Cancer of the Colon and Rectum）of surgically resected specimens and RECIST. Groups were classified as responders（ grade 2 or 3, CR or PR）or nonresponders（grade 0 or 1, SD or PD）, respectively. Response to CRT determined by histopathologic examination of surgically resected specimens and RECIST were as follows : responders（grade 2 or 3, n＝15）,（PR, n＝１４）, nonresponders（grade 0 or 1, n＝7）（, SD, n＝8）. Response rate was６８％（grade 2 or 3）and 63％（PR）. Two miRNAs（miR- 142, 223）with increased expression were identified that correctly differentiated responders from nonresponders of CRT by histopathologic examination. One overexpressed（miR-223）and 4 underexpressed miRNAs（miR-17, 20, 92, 106）differentiated responders from nonresponders of CRT by RECIST. Rectal cancer may have a distinct miRNA expression to predict pathological response to preoperative chemoradiotherapy

Can sufficient preoperative information of intracranial aneurysms be obtained by using 320-row detector CT angiography alone?

Abstract Purpose To determine whether sufficient pre-surgical treatment information of unruptured intracranial aneurysms can be obtained by using 320-row detector CT angiography (CTA) alone. Materials and methods We enrolled 40 consecutive patients with unruptured intracranial aneurysms. All patients were prospectively conducted to perform 320-detector CTA as the only preoperative modality. Two blinded readers independently assessed CTA images. Interobserver agreement and the agreement between CTA and surgical findings were determined by calculating the j coefficient. The referring neurosurgeons judged the usefulness of the information provided by CTA for treatment decisions. Results All patients had surgery without intraarterial digital subtraction angiography. Agreement between CTA and surgical findings was excellent for the aneurysm location (j = 1.0) and good for the shape (j = 0.71), neck (j = 0.74) and its relationship with adjacent branches (j = 0.71). Information obtained with 320-detector CTA was highly useful for surgical treatment in 37 of 40 (93 %) patients, although small perforators deriving from the aneurysm in 2 cases were not fully visualized on CTA images. Conclusion In most patients with unruptured intracranial aneurysms, sufficient pre-surgical treatment information can be obtained by using 320-detector CTA alone

Clinical role of Foxp3+regulatory T cell in Living donor related liver transplantation for prediction of life-threatening complications

Purposes : It is no doubt that regulatory T cells (Foxp3+CD4+CD25+T cells : Treg) play important roles in transplant immunity.We investigated the significance of Treg expression in acute stage of living donorrelated liver transplantation (LDLT) for the possibility of the sensitive marker for immunological state and homeostatic stress after liver transplantation. Methods : Peripheral blood was drawn from 5 recipients of LDLT preoperatively and on post operative 1, 4, 7, and 14 days. The peripheral blood mononuclear cells (PBMCs) were stained with CD4, CD25, Foxp3, and were analyzed with FACScan. This data was compared with clinical output of LDLT. Result : The populations of Treg were significantly decreased in all patients on day 1 after LDLT and significantly increased in patients who had early postoperative complications compared with patients who had no complications. Conclusions : The population of Treg in peripheral blood may reflect the surgical stress such as life-threatening complications after LDLT