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CD8+ T cells play an important role in the elimination of tumors. However, the underlying mechanisms involved in eliciting and maintaining effector responses in CD8+ T cells remain to be elucidated. Pellino1 (Peli1) is a receptor signal-responsive ubiquitin E3 ligase, which acts as a critical mediator for innate immunity. Here, we found that the risk of developing tumors was dependent on Peli1 expression. Peli1 was upregulated in CD8+ T cells among tumor-infiltrating lymphocytes (TIL). In contrast, a deficit of Peli1 enhanced the maintenance and effector function of CD8+ TILs. The development of Peli1-deficient CD8+ TILs prevented T-cell exhaustion and retained the hyperactivated states of T cells to eliminate tumors. We also found that Peli1 directly interacted with protein kinase C-theta (PKCθ), a central kinase in T-cell receptor downstream signal transduction, but whose role in tumor immunology remains unknown. Peli1 inhibited the PKCθ pathway by lysine 48–mediated ubiquitination degradation in CD8+ TILs. In summary, the Peli1–PKCθ signaling axis is a common inhibitory mechanism that prevents antitumor CD8+ T-cell function, and thus targeting Peli1 may be a useful therapeutic strategy for improving cytotoxic T-cell activity.

Supplementary Data from The Pellino1–PKCθ Signaling Axis Is an Essential Target for Improving Antitumor CD8+ T-lymphocyte Function

Supplementary Figure from The Pellino1–PKCθ Signaling Axis Is an Essential Target for Improving Antitumor CD8+ T-lymphocyte Function

CD8+ T cells play an important role in the elimination of tumors. However, the underlying mechanisms involved in eliciting and maintaining effector responses in CD8+ T cells remain to be elucidated. Pellino1 (Peli1) is a receptor signal-responsive ubiquitin E3 ligase, which acts as a critical mediator for innate immunity. Here, we found that the risk of developing tumors was dependent on Peli1 expression. Peli1 was upregulated in CD8+ T cells among tumor-infiltrating lymphocytes (TIL). In contrast, a deficit of Peli1 enhanced the maintenance and effector function of CD8+ TILs. The development of Peli1-deficient CD8+ TILs prevented T-cell exhaustion and retained the hyperactivated states of T cells to eliminate tumors. We also found that Peli1 directly interacted with protein kinase C-theta (PKCθ), a central kinase in T-cell receptor downstream signal transduction, but whose role in tumor immunology remains unknown. Peli1 inhibited the PKCθ pathway by lysine 48–mediated ubiquitination degradation in CD8+ TILs. In summary, the Peli1–PKCθ signaling axis is a common inhibitory mechanism that prevents antitumor CD8+ T-cell function, and thus targeting Peli1 may be a useful therapeutic strategy for improving cytotoxic T-cell activity.

The homeostatic balance between effector T cells and regulatory T cells (Tregs) is crucial for adaptive immunity; however, epigenetic programs that inhibit phosphorylation to regulate Treg development, peripheral expression, and suppressive activity are elusive. Here, we found that the Ssu72 phosphatase is activated by various T-cell receptor signaling pathways, including the T-cell receptor and IL-2R pathways, and localizes at the cell membrane. Deletion of Ssu72 in T cells disrupts CD4(+) T-cell differentiation into Tregs in the periphery via the production of high levels of the effector cytokines IL-2 and IFNγ, which induce CD4(+) T-cell activation and differentiation into effector cell lineages. We also found a close correlation between downregulation of Ssu72 and severe defects in mucosal tolerance in patients. Interestingly, Ssu72 forms a complex with PLCγ1, which is an essential effector molecule for T-cell receptor signaling as well as Treg development and function. Ssu72 deficiency impairs PLCγ1 downstream signaling and results in failure of Foxp3 induction. Thus, our studies show that the Ssu72-mediated cytokine response coordinates the differentiation and function of Treg cells in the periphery.

Psoriasis is one of the most common immune-mediated chronic inflammatory skin diseases. However, little is known about the molecular mechanism underlying the immunological circuits that maintain innate and adaptive immune responses in established psoriasis. In this study, we found that the Pellino1 (Peli1) ubiquitin E3 ligase is activated by innate pattern-recognition receptors (PRRs), such as Toll-like receptors (TLRs), and is highly upregulated in human psoriatic skin lesions and murine psoriasis-like models. Increased Peli1 expression is strongly correlated with the immunopathogenesis of psoriasis by activating hyperproliferation of keratinocytes in the S and G2/M phases of the cell cycle and promoting chronic skin inflammation. Furthermore, Peli1-induced psoriasis-like lesions showed significant changes in the expression levels of several T helper 17 (Th17)-related cytokines, such as IL-17a, IL-21, IL-22, IL-23, and IL-24, indicating that overexpression of Peli1 resulted in the sequential engagement of the Th17 cell response. However, the overexpression of Peli1 in T cells was insufficient to trigger psoriasis, while T cells were indispensable for disease manifestation. In summary, our findings demonstrate that Peli1 is a critical cell cycle activator of innate immunity, which subsequently links Th17 cell immune responses to the psoriatic microenvironment., Psoriasis: Regulatory protein linked to chronic inflammation An immune-regulating protein that mediates chronic inflammation in the skin offers a new therapeutic target for the autoimmune disorder psoriasis. A research team from South Korea led by Chang-Woo Lee from Sungkyunkwan University School of Medicine in Suwon and Heounjeong Go from the University of Ulsan College of Medicine in Seoul have discovered that Pellino1, a protein known to modulate immune responses to pathogens, is also found in abundance in the skin lesions of people with psoriasis. Using mouse models, the researchers showed how Pellino1 induces the proliferation of certain skin cells and triggers an inflammatory state through the activation of small proteins and immune cells normally involved in defense against infection. Targeting strategy that inactivate Pellino1 could help blunt the inflammatory signaling in the skin that drives the development of psoriatic lesions.

Small enterprises in the root industry are currently experiencing difficulties in fulfilling their deadlines due to the recent increase in the minimum wage, shortened working hours, and low productivity. Therefore, it is very important to establish a Manufacturing Execution System (MES) that can increase production and process efficiency with minimum manpower.

Growing evidence suggests a mechanistic link between steatohepatitis and hepatocellular carcinoma (HCC). However, the lack of representative animal models hampers efforts to understand pathophysiological mechanisms underlying steatohepatitis-related HCC. We found that liver-specific deletion of Ssu72 phosphatase in mice, leads to a high incidence of nonalcoholic fatty liver disease and nonalcoholic steatohepatitis, but not HCC. However, loss of Ssu72 drastically increased the probability of HCC developing, as well as the population of hepatic progenitors, in various chemical and metabolic syndrome-induced HCC models. Importantly, hepatic Ssu72 loss resulted in the induction of mature hepatocyte-to-progenitor cell conversion, by dedifferentiation orchestrated by Ssu72-mediated hypo-phosphorylation of hepatocyte nuclear factor 4α (HNF4α), a master regulator of hepatocyte function. Our findings suggest that Ssu72-mediated HNF4α transcription contributes to the progression of steatohepatitis-associated HCC by regulating the dedifferentiation potential of hepatocytes. Thus, targeting the Ssu72-mediated HNF4α signaling that underlies the pathogenesis of steatohepatitis-associated HCC development could be a novel therapeutic intervention for steatohepatitis-associated HCC.

The brain-expressed X-linked 4 (BEX4) gene has been recently identified as a mediator of microtubule hyperacetylation through sirtuin 2 inhibition and is highly overexpressed in human cancers. However, the gain-of-function molecular mechanism of the BEX4 gene in human cancers still needs to be elucidated. This study shows that BEX4 colocalizes and interacts with Polo-like kinase 1 (PLK1) at centrosomes, spindle poles, and midbodies, particularly during mitosis. Interestingly, PLK1-mediated phosphorylation upregulates the stability of BEX4 protein, and the PLK1–BEX4 interaction allows abnormal mitotic cells to adapt to aneuploidy rather than undergo apoptotic cell death. In summary, these results suggest that the oncogenicity of BEX4 is conferred by PLK1-mediated phosphorylation, and thus, the BEX4–PLK1 interaction is a novel oncogenic signal that enables the acquisition of chromosomal aneuploidy., Cancer: an enabler for defective division Tumors exploit a signaling mechanism that allows them to survive disruptions in cell division that would normally prove lethal. When normal cell division goes awry, it produces cells containing abnormal numbers of chromosomes, which exhibit numerous developmental defects. Researchers led by Geun-Hyoung Ha and Chang-Woo Lee, Sungkyunkwan University School of Medicine, South Korea, have learned how a safeguard that prevents this breaks down in cancer cells. They found that cancer cells produce elevated levels of a protein called BEX4 due to a chemical modification that renders this protein more stable. Cells that experience disrupted chromosomal sorting during cell division normally self-destruct through a process called apoptosis. Excessive BEX4 prevents apoptosis, however, allowing such damaged cells to proliferate. This fuels cancer growth but also creates opportunities for treatment with drugs that inhibit BEX4 stabilization.

DNA double-strand break (DSB) signaling and repair are critical for genome integrity. They rely on highly coordinated processes including posttranslational modifications of proteins. Here we show that Pellino1 (Peli1) is a DSB-responsive ubiquitin ligase required for the accumulation of DNA damage response proteins and efficient homologous recombination (HR) repair. Peli1 is activated by ATM-mediated phosphorylation. It is recruited to DSB sites in ATM- and γH2AX-dependent manners. Interaction of Peli1 with phosphorylated histone H2AX enables it to bind to and mediate the formation of K63-linked ubiquitination of NBS1, which subsequently results in feedback activation of ATM and promotes HR repair. Collectively, these results provide a DSB-responsive factor underlying the connection between ATM kinase and DSB-induced ubiquitination., Occurrence of DNA double-strand break (DSB) repair is important for genome integrity. Here, the authors reveal that Pellino1 is a DSB-responsive ubiquitin ligase required for promoting the accumulation of ATM and MRN complex at DSB sites via NBS1 ubiquitination.

Signal transducer and activator of transcription 3 (STAT3) orchestrates the differentiation of several cell types, including interleukin-17 (IL-17)-releasing Th17 cells. Dysregulation of Th17 cells results in chronic inflammatory responses. Ssu72 is a C-terminal domain phosphatase required for transcriptional regulation. However, the mechanism by which Ssu72 affects STAT3 activation and Th17 cell differentiation is unclear. Here, we found that Ssu72 overexpression suppresses STAT3 activation and Th17 cell responses in vitro. A systemic infusion of Ssu72 attenuates experimental autoimmune arthritis by reducing STAT3 activity and the differentiation of Th17 cells. It also reduces joint destruction, serum immunoglobulin concentrations and osteoclastogenesis but increases the number of marginal zone B cells and B10 cells. These effects are associated with reduced p-STAT3 levels and the suppression of Th17 cell formation in vivo. Based on these data, Ssu72 is related to STAT3 activation and the inflammatory response; and Ssu72 overexpression in T-cell-mediated immunity has potential utility for the treatment of autoimmune arthritis.

Hepatocyte chromosome polyploidization is an important feature of liver development and seems to be required for response to liver stress and injury signals. However, the question of how polyploidization can be tightly regulated in liver growth remains to be answered. Using a conditional knockout mouse model, liver-specific depletion of Ssu72 protein phosphatase was found to result in impairment in regulation of polyploidization. Interestingly, the aberrant polyploidization in Ssu72-depleted mice was associated with impaired liver damage response and increased markers of liver injury and seemed to mimic the phenotypic features of liver diseases such as fibrosis, steatosis, and steatohepatitis. In addition, depletion of Ssu72 caused deregulation of cell cycle progression by overriding the restriction point of the cell cycle and aberrantly promoting DNA endoreplication through G2/M arrest. Conclusion: Ssu72 plays a substantial role in the maintenance of hepatic chromosome homeostasis and would allow monitoring of liver function. (Hepatology 2016;63:247–259)

This paper presents a design for four band patch antenna by CPW feeding for the in-building mobile communication. Especially, a parasitic element is considered for beam direction control. In order to satisfy for the mobile communication service such as LTE (890 MHz band), PCS (1.8 GHz band), W-CDMA (2.0 GHz band) and Wi-Fi (2.43 GHz band), a CPW feeding structure and a circular patch with slit for broad bandwidth are designed. The simulated results were shown a good agreement with the measured ones of a proposed antenna.

The angular distribution (AD) of particles sputtered from a Si substrate in a CHF3 plasma at bias voltages between −200 and −400V was investigated using a specially designed experimental setup for controlling the angle of incident ions on the substrate. Particles were sputtered from a primary target substrate, which was placed in a Faraday cage and on the horizontal cathode plane of a plasma etcher, by bombardment with ions incident in a direction normal to the substrate. The sputtered particles were redeposited on the surfaces of SiO2 secondary targets, which were fixed in small pieces at different positions on the convave surface of a circular sample holder, which was positioned above the primary target. A line connecting the primary and secondary targets defined the sputtering angle of the etch products. The redeposition rate was estimated from the difference in the thickness of the secondary target in two independent experiments, with and without the primary target. The redeposition rate was plotted as a function of sputtering angle and, the AD was then obtained from the plot. X-ray photoelectron spectroscopy analysis of a Si primary target subjected to etching indicated that a steady-state CFx film with a thickness of about 50A was formed on the Si at a bias voltage of −400V. This film was thicker than the ion-energy transfer depth (30A), and, as a result, it can be concluded that particles redeposited on the secondary target were sputtered from a steady-state CFx film that had been formed on the Si primary target. The AD of particles sputtered from the Si primary target showed an over-cosine dependence on the sputtering angle (θ), corresponding to cos3–4θ, and the power of the over-cosine dependence increased with bias voltage. The characteristic changes in the AD support the view that particles contributing to the redeposition were generated largely by physical sputtering rather than by ion-enhanced chemical etching.

Surgical release of the elbow was performed in 27 patients with post-traumatic stiffness at a mean of 14.5 months after the initial injury. The outcome was related to whether there had been heterotopic ossification, which had occurred in 18 elbows and to whether, if there had been a fracture, it had involved the articular surface, which had occurred in 13 elbows. The final range of movement and the ratio of desired gain in each group were compared at a mean follow-up period of 22.5 months (12 to 43). The arc of movement of the elbow improved in all patients after the operation. The mean final arc was 110° in those with heterotopic ossification and 86° in those without (p = 0.001). The ratios of desired gain were significantly higher in patients with heterotopic ossification (88.2% vs 54.9%; p < 0.001). There was no significant difference in relation to involvement of the articular surface. Careful assessment of the cause of stiffness is important in order to achieve a satisfactory result from surgery for post-traumatic stiffness of the elbow.

We present a simple yet robust method for fabricating angled, hierarchically patterned high-aspect-ratio polymer nanohairs to generate directionally sensitive dry adhesives. The slanted polymeric nanostructures were molded from an etched polySi substrate containing slanted nanoholes. An angled etching technique was developed to fabricate slanted nanoholes with flat tips by inserting an etch-stop layer of silicon dioxide. This unique etching method was equipped with a Faraday cage system to control the ion-incident angles in the conventional plasma etching system. The polymeric nanohairs were fabricated with tailored leaning angles, sizes, tip shapes, and hierarchical structures. As a result of controlled leaning angle and bulged flat top of the nanohairs, the replicated, slanted nanohairs showed excellent directional adhesion, exhibiting strong shear attachment (≈26 N/cm 2 in maximum) in the angled direction and easy detachment (≈2.2 N/cm 2 ) in the opposite direction, with a hysteresis value of ≈10. In addition to single scale nanohairs, monolithic, micro-nanoscale combined hierarchical hairs were also fabricated by using a 2-step UV-assisted molding technique. These hierarchical nanoscale patterns maintained their adhesive force even on a rough surface (roughness 2 , second-generation TFT-LCD glass), which could replace the current electrostatic transport/holding system with further optimization.

A patterned TaN substrate, which is candidate for a mask absorber in extreme ultra-violet lithography (EUVL), was etched to have inclined sidewalls by using a Faraday cage system under the condition of a 2-step process that allowed the high etch selectivity of TaN over the resist. The sidewall angle (SWA) of the patterned substrate, which was in the shape of a parallelogram after etching, could be controlled by changing the slope of a substrate holder that was placed in the Faraday cage. The performance of an EUV mask, which contained the TaN absorber of an oblique pattern over the molybdenum/silicon multi-layer, was simulated for different cases of SWA. The results indicated that the optical properties, such as the critical dimension (CD), an offset in the CD bias between horizontal and vertical patterns (H-V bias), and a shift in the image position on the wafer, could be controlled by changing the SWA of the absorber stack. The simulation result showed that the effect of the SWA on the optical properties became more significant at larger thicknesses of the absorber and smaller sizes of the target CD. Nevertheless, the contrast of the aerial images was not significantly decreased because the shadow effect caused by either sidewall of the patterned substrate cancelled with each other.

Inflammatory fibroid polyp occurs very rarely in the jejunum and gastrointestinal bleeding as an initial manifestation of inflammatory fibroid polyp has not been reported. We report a case of a jejunal inflammatory fibroid polyp presenting with melena for 10 days. Upper gastrointestinal endoscopic examination was negative for any active bleeding lesions and abdominal angiography failed to localize the bleeding site as well. In contrast, computed tomography of the abdomen demonstrated a segmental wall thickening of the jejunum with a tumor-like mass lesion associated with dense contrast enhancement. Consistent with this, technetium 99m red blood cells scintigraphy exhibited red cell pooling at the right upper quadrant. On exploratory laparotomy, there was an active bleeding from the site of the jejunal tumor and a segmental resection was performed. Histologically, the tumor lesion of the jejunum was consistent with inflammatory fibroid polyp. Thus, we conclude that the tumor lesion was a cause of the gastrointestinal bleeding.

The mitotic checkpoint plays a critical role in preventing chromosome missegregation and the adaptation of aneuploid cells. BubR1 kinase is a member of the mitotic checkpoint machinery. To understand the function of BubR1-mediated mitotic checkpoint, we have screened a novel BubR1-interating protein, BEX, by performing yeast two-hybrid systems. Here, we show that overexpression of BEX protein with sustained spindle poison results in a production of aneuploid cells and less apoptotic cell death. Inhibition of BubR1 expression increases aneuploid cell populations, whereas knockdown of both BEX and BubR1 avoid polyploidy by undergoing apoptosis in BubR1-depleted aneuploid cells. In addition, forced BEX expression significantly induces the colony forming potential and accelerates the proliferation rate. Interestingly, BEX is localized on X chromosome, and seems to be selectively expressed at cancer cells and tissues. These results indicate that BEX expression leads to mitotic dysfunction, and contributes to unstable chromosome aneuploid cells to be preneoplastically adapted. Citation Format: Jin-Kwan Lee, Geun-Hyoung Ha, Janet Lee, Chang-Woo Lee. BEX protein attenuates the mitotic checkpoint and induces preneoplastic aneuploidy. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5086. doi:10.1158/1538-7445.AM2014-5086

The angular dependences of SiO2 etch rates for C4F6/O2/Ar and C4F6/CH2F2/O2/Ar plasmas were investigated using a Faraday cage system. In the absence of CH2F2, the steady-state fluorocarbon film that formed on the SiO2 surface was thin enough (

We present analysis of adhesion properties of angled polymer nanohairs with a wide range of leaning angles from 0° to 45° and ultraviolet (UV)-curable polyurethane acrylate (PUA) materials of two different elastic moduli (19.8 and 320 MPa). It is demonstrated that shear adhesion and adhesion hysteresis can be greatly enhanced by increasing the leaning angle of nanohairs both for soft and hard materials due to increased contact area and reduced structural stiffness.

A method for controlling the direction of Si etch profiles was developed using a Faraday cage system and a conventional gas-chopping process. The gas-chopping process consisted of sequentially alternating etching and deposition steps using SF 6 and C 4 F 8 plasmas, respectively. The single-directional oblique etching was achieved using a Faraday cage having a top horizontal grid plane, inside of which a tilted substrate holder was placed. The double-directional etching was also obtained using a cage having two slanted grid planes. The double-directional etch profiles were either symmetrically or asymmetrically oblique according to the angle of the sample holder. During the oblique-directional etching, the shadowing effect by the bombardment of tilt-angled ions was found to affect etch profiles. Due to the shadowing effect, the top width of the pattern and the etch depth decreased as the ion-incident angle increased, and a fluorocarbon film accumulated in the shadow area. By regulating the process conditions to allow a higher mask selectivity, an oblique Si etch profile with a high aspect ratio (etch depth = 5700 nm and aspect ratio = 9.5) was obtained.

High aspect ratio SiO 2 contact holes were etched using a cyclic process, which consisted of alternating etching and deposition steps using C 4 F 6 /CH 2 F 2 /O 2 /Ar and C 4 F 6 /CH 2 F 2 /Ar plasmas, respectively, to minimize the sidewall bowing of the hole. A CF x -film deposition step was added to recover the eroded slope of the mask and to deposit an additional passivation film on the sidewall. The introduction of the deposition step also improved the etch selectivity of SiO 2 toward the amorphous carbon layer mask and the open ratio of the contact hole, which was defined as the ratio of the hole diameter at the bottom to that at the top of the hole. By regulating the durations of the deposition and etching steps in the cyclic process, the degree of bowing, which was 9 nm when using a continuous-etching process, was reduced to 1 nm during the etching of a 2.3 μm deep SiO 2 contact hole with a diameter of 118 nm.

The etching characteristics of tantalum nitride (TaN), a mask absorber in extreme UV lithography, was investigated by observing the angular dependence of its normalized etch yield in CF 4 /Ar and CHF 3 /Ar inductively coupled plasmas (ICPs). The direction of plasma ions incident on the substrate surface was controlled in a specially designed etcher that contained a Faraday cage and substrate holders of different slope angles. Experiments performed at different ICP powers, combined with analyses of the sample surface by X-ray photoelectron spectroscopy and plasma gases by optical emission spectroscopy, showed that as the ICP power increased, the mechanism involved in the etching of the TaN substrate changed from physical sputtering to chemical sputtering in a CF 4 plasma while the mechanism changed from chemical sputtering to physical sputtering in a CHF 3 plasma. A tantalum native oxide film formed on the substrate surface decreased the etch rates by suppressing the transfer of ionic momentum to TaN. However, hydrogen atoms present in a CHF 3 plasma reduced the thickness of the oxide layer and consequently enhanced the etch rates of the substrate.

Background: Thyroid nodules are a common disease in clinical practice. The prevalence of thyroid nodules has recently been increased by according to the development of thyroid ultrasonography. Thyroid nodules are more commonly found in women, but the potential for malignant nodules is much higher in men. So, we aimed to focus on the prevalence of thyroid nodules in the adult male population. Methods: We studied men over the age of 30 who visited our health care center for routine health check-ups from January, 2005 to December, 2005. After excluding the patients with previous thyroid disorders, 1081 men were selected to undergo thyroid ultrasonography for detecting the presence of thyroid nodules. If nodules were found, then their size and numbers were recorded. These data were then correlated with the age of the patients. If needed, ultrasound-guided fine needle aspiration was performed. Results: Among the 1,081 subjects, thyroid nodules were detected in 152 (14.1%) with its prevalence increasing with the increasing age of the patients (age 30 to 49: 12.3%, over 50: 17.2%, P = 0.026). Among these study subjects, nodules larger than 5 mm in size were detected in 99 patients and fine needle aspirations were performed on 53 of these patients. Six patients were diagnosed with papillary carcinoma. Conclusion: The prevalence of thyroid nodules in the male population was 14.1%, with an increasing prevalence in the over 50 age group. (J Kor Endocrine Soc 22:112~117, 2007)

The dependence of Si3N4 etch rates and the etch selectivity of SiO2 to Si3N4 on ion-incident angles was studied for different bias voltages in a high-density C4F8 plasma. A Faraday cage and specially designed substrate holders were used to accurately control the angles of incident ions on the substrate surface. The normalized etch yield (NEY), defined as the etch yield obtained at a given ion-incident angle normalized to that obtained on a horizontal surface, was unaffected by the bias voltage in Si3N4 etching, but it increased with the bias voltage in SiO2 etching in the range of −100to−300V. The NEY changed showing a maximum with an increase in the ion-incident angle in the etching of both substrates. In the Si3N4 etching, a maximum NEY of 1.7 was obtained at 70° in the above bias voltage range. However, an increase in the NEY at high ion-incident angles was smaller for SiO2 than for Si3N4 and, consequently, the etch selectivity of SiO2 to Si3N4 decreased with an increase in the ion-incident angle. The ...

The dependence of SiO2 etch rate on sidewall angle, as affected by different bottom materials, in an inductively coupled CHF3 plasma was investigated. The bottom materials were SiO2, Si, and fluorocarbon polymer, and the bias voltage of the plasma was varied from −50to−400V. Differences in the angular dependency of the etch rate were observed for the different bottom materials at sidewall surface angles higher than 75°, in which case the amounts of bottom-emitted particles impinging on the sidewall surface were relatively large and the transfer of ion energy to the SiO2 substrate was relatively small due to the formation of a fluorocarbon passivation film. The extent that the bottom materials affected the dependence of etch rate on sidewall angle changed, depending on the bias voltage range. When the bias voltage was in the range between −50 and −200V, the effect of a SiO2 bottom was the smallest and those of Si and fluorocarbon polymer were essentially the same. However, at −400V, the effect was substant...

Relationships between sidewall and bottom etch rates during SiO2 etching in a CHF3 plasma were studied using a Faraday cage system, which permitted the sidewall angle to be controlled with respect to ions incident on the surface and the sidewall and bottom surfaces to be examined on a scale larger than in actual microfeatures. The etch rates for the sidewall were significantly decreased at sidewall angles near 75° and the resulting angular dependence of the etch rates decreased monotonously following an “inversely S-shaped” curve. On the other hand, the degree of sidewall effect (DSE), which represents changes in the bottom etch rates due to the presence of the sidewall, showed a characteristic “W-shaped” curve with respect to sidewall angle, due to a decrease in the bottom etch rates at sidewall angles near 75°. The relationship between the sidewall etch rate and the DSE was affected by a thick, rough steady-state fluorocarbon film formed on the sidewall surface. The thickness, roughness, and F∕C ratio o...

Factors that affect microtrench formation during the etching of SiO2 in a CF4 plasma were investigated using an experimental set-up, which comprised a Faraday cage and step-shaped substrates consisting of a SiO2 bottom and slanted sidewalls of different materials. This set-up permitted the etched micropattern to be observed on a magnified scale under conditions that are similar to actual processes. SiO2 and fluorocarbon polymer were used as sidewall surface materials to investigate the effect of sidewall properties on the microtrench. The depth of the microtrench characteristically changed with the sidewall angle, reaching a maximum at 70° under the condition used in this study. This can be explained by the effect of two competitive factors: secondary etching of the bottom by ions reflected from the sidewall, which contributes to the bottom etch rate, and the shadowing effect of the sidewall, which decreases the etch rate. Secondary etching, as estimated from the difference in the bottom etch rates between two cases of an ordinary sidewall and a sidewall with an extremely rough surface, showed a maximum at a sidewall angle of 80°–82.5°, while the shadowing effect was increased monotonously with sidewall angle. The rates of secondary etching were higher for the polymer sidewall than for the SiO2 sidewall for sidewall angles lower than 70°, but opposite relative magnitudes were observed for angles higher than 70°. The result obtained at angles lower than 70° can be explained based on a model in which a fluorocarbon film formed on the sidewall, which was particularly thick for a polymer sidewall, acted as a source of etchant radicals, thus contributing to bottom etching. The opposite trend observed at angles higher than 70° can be attributed to the roughness of the sidewall surface, which was higher for the polymer sidewall, which affected the reflection of ions on the surface and, eventually, secondary etching.

A silicon substrate, masked with oxide lines with a spacing of 1μm, was etched using a gas-chopping process designed to enhance mask selectivity and produce a highly anisotropic etch profile with ripple-free sidewalls. The gas-chopping process employed a high bias voltage of −200V and a Faraday cage in the etching step. The use of a high bias voltage relieved the curvature of sidewall ripples that are generated during etch cycles due to the bombardment of energetic ions on the convex portions of the ripples, thus flattening the sidewall surface. The use of a Faraday cage served to suppress the erosion of the mask, thus leading to a high mask selectivity. This can be attributed to an increase in the intrinsic etch selectivity of the Si substrate to the mask due to an increase in the ratio of neutral to ion fluxes on the substrate, and by the suppression of mask faceting due to a reduction in the etch yields of the oxide mask and a CFx film formed on the surface of the mask.

The dependences of etch rates on the angle of ions incident on the substrate surface in four plasma/substrate systems that constitute the advanced Bosch process were investigated using a Faraday cage designed for the accurate control of the ion-incident angle. The four systems, established by combining discharge gases and substrates, were a SF6/poly-Si, a SF6/fluorocarbon polymer, an O2/fluorocarbon polymer, and a C4F8/Si. In the case of SF6/poly-Si, the normalized etch rates (NERs), defined as the etch rates normalized by the rate on the horizontal surface, were higher at all angles than values predicted from the cosine of the ion-incident angle. This characteristic curve shape was independent of changes in process variables including the source power and bias voltage. Contrary to the earlier case, the NERs for the O2/polymer decreased and eventually reached much lower values than the cosine values at angles between 30° and 70° when the source power was increased and the bias voltage was decreased. On th...

The dependences of bottom and sidewall etch rates on the bias voltage and source power in four plasma/substrate systems constituting the advanced Bosch process were investigated using a Faraday cage and a step-shaped substrate specially designed for the accurate observation of lateral and vertical etch rates. The four systems, established by combining discharge gases and substrates, were SF6/poly-Si, SF6/fluorocarbon polymer, O2/fluorocarbon polymer, and C4F8/Si. For etch systems using SF6/poly-Si, SF6/polymer, and O2/polymer, the degree of anisotropy showed a higher dependence on the bias voltage than on the source power. As the bias voltage was increased, the degree of anisotropy obtained in SF6/poly-Si decreased while that for the SF6/polymer and O2/polymer increased. The contribution of spontaneous etching by reactive radicals to the etch rates increased in the order of SF6/polymer

The effects of C∕F ratio in fluorocarbon gases, used in the plasma etching of SiO2, on the properties of sidewalls of etched trenches, as affected particularly by the redeposition of particles emitted from the bottom, were investigated using three different plasma gases, CF4, CHF3, and C4F8. The use of a Faraday cage and step-shaped substrates permitted an effective analysis of the chemical and physical properties of the sidewall surface in a scale larger than that for micro-patterns. The step-shaped substrates consisted of one bottom and two sidewalls: One of the sidewalls was affected by bottom-emitted particles, designated as sidewall (A), and the other was unaffected by the particles, designated as sidewall (B). Comparison of the surface properties of the two sidewalls allowed us to observe the redeposition effect, independently from other complicated phenomena involved in the plasma etching. For all cases of CF4, CHF3, and C4F8, the rate of film deposition on sidewall (A) was larger than that on side...

Although clonorchiasis is one of the most common parasitic infections in Korea, it is unusual that the disease presents peripheral eosinophilia and pulmonary infiltrations.(eosinophilic pneumonia) A case of clonorchiasis manifested as diffuse nodular pulmonary infiltrations was presented. The patient had a mild to moderate pain on the right upper quadrant of the abdomen, cough, dyspnea, and unknown cause of marked eosinophilia (up to 71.4% of total white blood cell count). The causal organism, clonorchis sinensis was found by the identification of parasite ova in the stool We confirmed eosinophilic pneumonia with bronchoalveolar larvage analysis and transbronchial lung biopsy. With corticosteroid and praziquantel treatment, clinical symtoms and pulmonary infiltrations on the chest roentgenograms had rapidly improved. We report a case of eosinophilic pneumonia related to clonorchiasis and review the pertinent literature.

In healthy adults, diagnosis of aspiration of foreign body into tracheobronchial tree is not difficult because various symptoms such as dyspnea, coughing, or cyanosis develop when foreign body is aspirated into tracheobronchial tree. But unless a clear history of an aspiration event can be obtained, diagnosis will be delayed. Early complications of tracheobronchial foreign body aspiration include asphyxia, cardiac arrest, dyspnea, laryngeal edema, and cyanosis. Late complications include pneumonia, lung abscess, bronchiectasis, hemoptysis, bronchial stenosis, and polyp. Treatment is removal of foreign body by operation or bronchoscopy. Currently, flexible bronchoscopy is preferred in adults than rigid bronchoscopy. A 36-year-old male visited to Dongkang hospital due to productive coughing and dyspnea. On auscultation, focal inspiratory wheezing was heard. On chest PA, mild emphysematous change was seen Flexible bronchoscopy was done. Bronchoscopically, mucoid impaction, surrounding inflammation, foreign body lodged in the right lower lobe bronchus, and interbronchial fistula(between right middle and lower lobe bronchus) were seen Foreign body( sized antacid package) was removed by flexible bronchoscopy. Later, history of aspiration of a piece of antacid package was found. We report a case of recurrent bronchitis with interbronchial fistula as a result of occult aspiration of foreign body with review of the literatures.