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Background Rapidly proliferating stomach stem cells have been predicted to be located at the isthmus of both corpus and antrum. We recently identified such stem cells by using 270 bp Runx1 enhancer element, eR1 (Gastroenterol, 2017). In addition, eR1 also marked small number of fully differentiated chief cells in the corpus. We investigated whether chief cells have stem cell activity and can be an origin of gastric cancer, particularly because there are disagreements among the researchers. Methods We generated knock-in mice of pepsinogen C-CreERT2 and crossed them with Rosa26-EYFP mice or pepsinogen A-CreERT2 and crossed them with Rosa26-tdTomato mice for lineage tracing. PGC-CreERT2 mice were also crossed with K-rasG12D/+, Trp53flox/flox and Apcflox/floxmice for carcinogenesis model. Those mice were injected with Tamoxifen 2 mg alternate days for 6 timesto activate Cre recombinase in the chief cells. Results By activating Cre recombinase, we showed that relatively small number of chief cells was retro-differentiated into neck, parietal, pit and enteroendocrinecells suggesting that chief cells underwent differentiation in exact reverse order to make a complete gland unit. When K-rasG12Dwas activated by pepsinogen C-CreERT2, induction of metaplasia was observed. Addition of p53 knockout with K-rasG12Dinto chief cells showed increasing number of glands with metaplasia. Furthermore, addition of APC knockout combination with K-rasG12Dand p53f/fshowed invasive intestinal type gastric cancer in the corpus. These results suggest that at least small subfraction of chief cell have stem cell activity and potential to give rise to gastric cancer. Recently, new entity of gastric adenocarcinoma has been proposed which called Gastric adenocarcinoma of fundic gland type (chief cell predominant type). We might have showed those type of gastric carcinogenesis. Conclusions Chief cell in stomach have stem cell activity and potential to develop gastric cancer. Legal entity responsible for the study The authors. Funding Singapore Gastric Cancer Consortium. Disclosure All authors have declared no conflicts of interest.

It is well known that site effects often contribute to earthquake damage. The first time that site effects during an earthquake were pointed out in India was by MacMurdo (1823) for the 1819 Mw 7.8 earthquake (Figure 1). He wrote in his report, “At Anjar, half of the town, which is situated on low rocky ridges, suffered comparatively nothing; whilst the other half, upon a slope to a plain of springs and swamps, into which the town is drained, was entirely overturned.” Site effects at Anjar city were noticed again during the 1956 Mw 6.0 Anjar earthquake and also during the 2001 Mw 7.6 earthquake (Figure 1). At the time of the 1956 event, Tandon (1959) noted, “At Anjar, it has already been mentioned earlier that both in 1819 and also in the present earthquake, the eastern portions of the town built on soft ground suffered extensive damage while the western portions built on trap rock foundations escaped with only minor damage.” Recently, EERI 2002 reported for the 2001 Bhuj earthquake: ...damage was primarily restricted to the five wards (3, 4, 5, 9, and 10) of the old Anjar town. Wards 3, 4, and 10 in old Anjar sustained near total collapse of all buildings. These wards were also damaged during the 1956 Anjar earthquake. Ward 10 is apparently reclaimed from a 300–400 years old pond. Wards 5 and 9 sustained lower level of damages in both this earthquake and the 1956 event... as shown in Figure 2. In this article, we use high-resolution satellite imagery (GSDMA 2008) to categorize Anjar city into three types of scenarios: severely damaged, less damaged, and undamaged (Figure 3) as a result of the 2001 earthquake. The severely damaged area is clearly shown in the eastern part of old Anjar city (Figure 3 …

X-ray diffuse scattering for single crystals of KTa1-xNbxO3 (x = 0, 0.007 and 0.011) has been measured. For the sample of x = 0.011, peculiar x-ray diffuse scattering is observed above the phonon-frozen-in temperature (30 K). By an analysis of the diffuse scattering intensities, the average radius of the ferroelectric microregions is found to grow up to around 4 nm with decreasing temperature from 100 K down to 30 K. Anisotropic distributions of the diffuse scattering indicate off-centred shift of Nb and Ta ions to the 111-direction. Moreover, lattice constants for x = 0.011 below 30 K exhibit negative expansion, which is found neither in pure KTaO3 nor in KTa1-xNbxO3 (x = 0.007) at low temperatures. These results are successfully explained by introducing the effective classical potential (ECP) method for the anharmonic oscillators. The quantum contribution to mean square displacement of Nb and Ta ions from an average position is also calculated by the ECP method.

The pattern transfer of SiO2 hard masks into polytetrafluoroethylene, parylene-N, and poly(arylene ether) (PAE-2) has been characterized in an inductively coupled plasma source. Selected results obtained with blanket parylene-AF4 films are included in this work. These dielectrics offer a relatively low dielectric constant (k∼2–3) and are candidate materials for use as intra- and interlayer dielectrics for the next generations of high-speed electronic devices. Successful patterning conditions were identified for Ar/O2 and N2/O2 gas mixtures. It was found that the formation of straight sidewalls in Ar/O2 discharges relies on the redeposition of oxygen-deficient etch products on the feature sidewall. Furthermore, the etch rates of parylene-N, parylene-F, and PAE-2 for blanket and patterned films could be captured by a semiempirical surface coverage model, which balances the adsorption rate of oxygen and the ion-induced desorption rate of oxygenated etch products.

The etch rate of silicon nitride (Si3N4) in the afterglow of fluorine-containing plasmas is strongly enhanced when both nitrogen and oxygen are added to the remote discharge. This effect is attributed to the formation of nitric oxide (NO), which we identify as a highly reactive precursor for the etching of Si3N4. The Si3N4 etch rate, surface oxidation, and the depletion of the surface of N atoms show a linear dependence on the NO density. In order to determine the products of the NO reaction at the Si3N4 surface, mass spectrometry was performed in immediate proximity to the surface with a specially designed movable sampling orifice. Both SiF4 and N2 are identified as primary etch products, but a smaller amount of N2O was also detected. Based on our results, we suggest that NO enhances the removal of N from the Si3N4 surface by the formation of gaseous N2, and leaving behind an O atom, while the overall surface oxidation remains very low, and the reactive layers are very thin. This modified surface reacts ...

Cryptosporidium parvum infection and the pattern of oocyst shedding were observed in calves. A total of 480 fecal samples were collected from 30 calves (age, < or =30 days) over a period of 10 months from June 1998 to March 1999. A sucrose centrifugal flotation technique revealed 28/30 (93%) calves were passing Cryptosporidium oocysts. Oocyst shedding was first detected on the sixth day after birth, with 8% of the calves testing positive. This rate increased day by day and reached approximately 80% by day 15. Oocyst shedding varied from 1 to 13 days, with a mean of 7 days. Calves infected with C. parvum had a significantly higher rate of diarrhea (33%) than non-infected calves (8%) (P

This article describes results obtained using various plasma and surface diagnostics in a study of inductively coupled fluorocarbon plasmas in which the amount of capacitive coupling was systematically varied. It is found that the plasma density decreases while the electron temperature increases as the amount of capacitive coupling is increased at a constant source power level. The rate at which the dielectric coupling window is eroded is found to scale with both the peak-to-peak rf voltage and the ion current density, and the dielectric window erosion is found to influence the resulting plasma gas-phase chemistry. The changes in plasma electrical and chemical characteristics have a large impact on the surface processes occurring in inductively coupled fluorocarbon plasmas such as fluorocarbon deposition, fluorocarbon etching, SiO2 etching and Si etching. Further, we show how the selective SiO2-to-Si etch process changes with varying capacitive coupling.

A highly selective dry etching process for the removal of silicon nitride (Si3N4) layers from silicon and silicon dioxide (SiO2) is described and its mechanism examined. This new process employs a remote O2/N2 discharge with much smaller flows of CF4 or NF3 as a fluorine source as compared to conventional Si3N4 removal processes. Etch rates of Si3N4 of more than 30 nm/min were achieved for CF4 as a source of fluorine, while simultaneously the etch rate ratio of Si3N4 to polycrystalline silicon was as high as 40, and SiO2 was not etched at all. For NF3 as a fluorine source, Si3N4 etch rates of 50 nm/min were achieved, while the etch rate ratios to polycrystalline silicon and SiO2 were approximately 100 and 70, respectively. In situ ellipsometry shows the formation of an approximately 10-nm-thick reactive layer on top of the polycrystalline silicon. This oxidized reactive layer suppresses etching reactions of the reactive gas phase species with the silicon.

The etching of silicon in remote microwave discharges fed with NF3/O2 has been investigated. In situ ellipsometry and x-ray photoelectron spectroscopy (XPS) were used to monitor surface effects, while mass spectrometry was used to monitor the gas phase dynamics. Varying the microwave power from 600 to 1400 W has little effect, due to the near complete dissociation of the NF3, even at lower powers. For discharges containing pure NF3, the poly-Si etch rate increases linearly with NF3 flow. When a low proportion of O2 (O2/NF3=0.1) is added to the discharge, the etch rate increases quickly to its maximum of ∼700 nm/min. With further O2 addition, this etch rate decreases below that observed for pure NF3 processing. The fluorine concentration in the processing region decreases for all O2 additions by a dilution effect. For pure NF3 discharges, XPS measurements reveal 1–2 nm thick, highly fluorinated reaction layers with a gradual loss of fluorine content as the NF3 flow is increased. Specimens processed with bo...

Successful pattern transfer of 0.36–0.62 μm features into fluorinated silicon dioxide, hydrogen silsesquioxane (HSQ), and methyl silsesquioxane (MSQ) has been demonstrated in a transformer coupled plasma (TCP) source using fluorocarbon feedgas chemistries. These films have a lower dielectric constant than conventional SiO2. It is this property that makes them attractive for implementation in future integrated circuit technology. The etching of these novel dielectrics was compared to conventional SiO2. We have observed that the different chemical makeup of these SiO2-like dielectrics does not affect the etching when weakly polymerizing gases are used, such as CF4. In this case, the etch rate is primarily dependent on the ion energy. For more polymerizing chemistries, like CHF3 or C3F6/H2 gas mixtures, x-ray photoelectron spectroscopy analysis showed that an increasing steady state fluorocarbon film thickness limits the ion and neutral flux at the interface of the various dielectrics. It is suggested that, ...

The etching of silicon nitride (Si3N4) and silicon dioxide (SiO2) in the afterglow of NF3 and NF3/O2 microwave discharges has been characterized. The etch rates of both materials increase approximately linearly with the flow of NF3 due to the increased availability of F atoms. The etch rate of Si3N4 is enhanced significantly upon O2 injection into the NF3 discharge for O2/NF3 ratios of 0.3 and higher, whereas the SiO2 etch rate is less influenced for the same flow ratios. X-ray photoelectron spectroscopy of processed Si3N4 samples shows that the fluorine content of the reactive layer, which forms on the Si3N4 surface during etching, decreases with the flow of O2, and instead oxidation and nitrogen depletion of the surface occur. The oxidation of the reactive layer follows the same dependence on the flow of O2 as the etch rate. Argon actinometry and quadrupole mass spectrometry are used to identify reactive species in the etching of both materials. The atomic fluorine density decreases due to dilution as O...

In metallic sodium, a characteristic waiting time, which is the incubation time until phase transition starts, appears above M s at a fixed temperature. Small-angle neutron scattering from clusters of the low-temperature phase is observed, which shows good agreement with the aggregation-of-spheres model, whose radius distribution is a Maxwell distribution function. Using the aggregation-of-spheres model, the average radius, r 0 , of clusters of the low-temperature phase was found to be 57.2 A. Moreover, abnormal small-angle neutron scattering from local fluctuations is seen during the waiting time, where this waiting time is related to the nucleation process in the martensitic phase transition.

The remote plasma chemical dry etching of polycrystalline silicon was investigated using various CF4/O2/N2 gas compositions. The effects of O2 and N2 addition on the etch rate and surface chemistry were established. Admixing O2 to CF4 increases the gas phase fluorine density and increases the etch rate by roughly sevenfold to a maximum at an O2/CF4 ratio of 0.15. The addition of small amounts of N2 (N2/CF4=0.05) can again double this etch rate maximum. Strong changes in surface chemistry were also seen as a result of N2 addition to CF4/O2. Real-time ellipsometry and atomic force micro-roughness measurements reveal that nitrogen addition at low O2/CF4 ratios leads to the smoothing of surfaces, but to increased oxidation at high O2/CF4 ratios. Based on etch rate data and gas phase species analysis, we propose that NO plays an important role in the overall etching reaction. Variable tube lengths separated the reaction chamber from the discharge. These tubes were lined with either quartz or Teflon liners. In ...

Synopsis Objective The objective of this study was to clarify the effects of different body washing methods on skin texture. Methods Subjects were nine healthy women in their 20s. Skin on the inside of the forearms was washed every day for 4 weeks with protective washing (right forearm) and with non-protective washing (left forearm). We performed comparison of the right forearm and the left forearm. For the evaluation of skin texture, the interval of the sulcus cutis, and the mean and variance of the thickness of the sulcus cutis on digitized images were measured. Moreover, the numbers of equilateral triangles consisting of sulcus cutis were counted to evaluate skin texture. Results From the first week, the interval of sulcus cutis was significantly narrower with protective washing than with non-protective washing. The numbers of equilateral triangles increased significantly more with protective washing than with non-protective washing in weeks 1, 2 and 4. Although this study found no significant difference in mean of the thickness of the sulcus cutis, the interval of sulcus cutis and the number of triangles differed significantly with protective washing. The narrower intervals between sulcus cutis mean finer-textured skin and sulcus cutis are formed by triangles or quadrilaterals, and the more uniform these shapes are, the finer and more regular the texture Therefore, skin texture may have become finer as a result of protective washing. Conclusion These findings suggest that protective washing produces an even skin texture. They also suggest that number of equilateral triangles, as used in this study, may be useful as an index of skin texture. Resume Objectif L'objectif de cette etude etait de clarifier les effets des differentes methodes de lavage du corps sur la texture de la peau. Methodes Les sujets etaient 9 femmes en bonne sante entre 20 et 30 ans d’âge. La peau sur la face interne des avant-bras a ete lavee tous les jours pendant 4 semaines avec le lavage de protection (de l’ avant-bras droit) et lavee avec de non-protection (avant-bras gauche). Nous avons effectue la comparaison de l’ avant-bras droit et l'avant-bras gauche. Pour l’evaluation de la texture de la peau, l'intervalle des sulci cutis, et la moyenne et la variance de l’epaisseur du sulcus cutis ont ete mesurees sur des images numerisees. En outre, le nombre de triangles equilateraux composes de sulci cutis ont ete comptes pour evaluer la texture de la peau. Resultats Des la premiere semaine, l'intervalle des sulci cutis etait significativement plus etroit avec le lavage de protection qu'avec le lavage non-protection. Le nombre de triangles equilateraux a augmente significativement avec le lavage protecteur qu'avec le lavage non-protecteur au cours des semaines 1, 2 et 4. Bien que cette etude n'ait trouve aucune difference significative dans la moyenne de l’epaisseur des sulci cutis, l'intervalle des sulci cutis et le nombre de triangles differaient significativement avec lave- protection. Les intervalles etroits entre les sulci cutis signifie que la peau a une plus fine texture; les sulci cutis sont formes par des triangles ou en quadrilateres, et plus ces formes sont uniformes, plus la texture est fine. En consequence, la texture de la peau peut avoir ete rendue plus fine a la suite de lavage de protection. Conclusion Ces resultats suggerent que le lavage de protection produit une texture lisse de la peau. Ils suggerent egalement que le nombre de triangles equilateraux, tel qu'il est utilise dans cette etude, peut etre utile comme indice de la texture de la peau.

The chemical dry etching of silicon nitride (Si3N4)and silicon nitride (SiO2) in a downstream plasma reactor using CF4, O2, and N2 has been investigated. A comparison of the Si3N4 and SiO2 etch rates with that of polycrystalline silicon shows that the etch rates of Si3N4 and SiO2 are not limited by the amount of fluorine arriving on the surface only. Adding N2 in small amounts to a CF4/O2 microwave discharge increases the Si3N4 etch rate by a factor of 7, but leaves the SiO2 etch rate unchanged. This enables etch rate ratios of Si3N4 over SiO2 of 10 and greater. The Si3N4 etch rate was investigated with respect to dependence of tube length, tube geometry, and lining materials. Argon actinometry has shown that the production of F atoms in the plasma is not influenced by the addition of N2 to the discharge. Mass spectrometry shows a strong correlation between the Si3N4 etch rate and the NO concentration. X‐ray photoelectron spectra of the silicon nitride samples obtained immediately after the etching proces...

The reactive gas cluster injection process is an etching method that uses a neutral cluster beam without plasma. ClF3‐Ar neutral cluster was generated and the Si etching characteristics with this beam were investigated. ClF3 is very high reactive gas. Adiabatic expansion of a high‐pressure gas through a conical nozzle is utilized for the formation of cluster beams. The source gas was a mixture of ClF3 (6%) with Ar (94%). The etching rate increased with source gas pressure nonlinearly, and the etching rate achieved more than 30 μm/min at 0.85 MPa. Although the irradiation energy was very low (

Gas cluster ion presents various irradiation effects such as high sputtering yields. It is important to study the optimum condition of incident cluster ion beam for applications in surface modification technology. In this study, the effects of incident energy and chamber pressure on the sputtering yield with gas cluster ion bombardment were investigated. The incident mean cluster size was 2000 atoms/ion and incident energy was 10–80 keV. The number of collisions with residual gas during transportation was in the range 1–20. The sputtering yield with gas cluster ion beam increased nonlinearly with increasing incident cluster energy. However, cluster ion beam easily lose their energy by collision with residual gas, and the sputtering yield decreased rapidly. For using gas cluster ion beam efficiently, the collision frequency along transportation should be kept less than a few times.

Seabed resources like sea-floor hydrothermal deposits and methane hydrate have lately become a subject of special interest as potential alternative resources for the future. It is, however, difficult to estimate accurate abundance of those resources. One of the reasons is considered that effective methods for such exploration have not been well established. On the other hand, undersea technology and exploration technique on land have recently achieved remarkable development. Thus appropriate exploration near the sea floor must advance great development of the seabed resources. From this point of view, we started a project to develop new deep-sea exploration tools for the seabed resources by electrical and magnetic methods with financial support of the Ministry of Education, Culture, Sports, Science & Technology (MEXT). In this project, we are working on research and development regarding measurement of the magnetic field with high resolution and high sampling rate, electrical exploration with accurately controlled source signals, electrical exploration tools for shallow and deep targets, versatile instruments of electrical and magnetic explorations with multi-platforms (deep-tow system, ROV (Remotely Operated Vehicle), and AUV (Autonomous Underwater Vehicle)), comprehensive analyses of electrical, magnetic, acoustic and thermal data, and so on. We finished basic designs of the magnetic and electrical observation systems last year, and we are now manufacturing each instrument. So far, the first test of the magnetic exploration system was carried out in the Kumano Basin during the R/V Yokosuka cruise in July, 2009. We will present the outline and the current state of the project in this presentation.

Smoothing high-temperature superconductor (HTS) surfaces, especially HTS thin-film surfaces, is crucial for HTS thin-film device processing. In this letter, we describe a method to planarize the surface of a YBa2Cu3O7−δ HTS film down to a smoothness with a standard deviation of 1 nm or better. The method includes first smoothing the HTS surface by ion cluster beam bombardment, followed by annealing in oxygen ambient to regrow the damaged surface layer. Additional YBCO layers can be grown epitaxially on the treated surface, even without removing the top surface layer, which contained some residual damage after annealing. This method can be integrated into HTS circuit fabrication as a key step of planarization.

By comparing the etching characteristics of silicon and silicon nitride in CF4/O2/N2 microwave downstream plasmas we demonstrate clearly how low concentrations of energetic species can play a dominant role in remote plasma processing: Injection of 5% N2 to a CF4/O2 plasma increases the silicon nitride etch rate by a factor of 7, while not significantly affecting the bulk composition of the discharge. Downstream injection of N2 is ineffective. Using surface spectroscopies we directly show a dramatic enhancement of the reactivity of fluorine and oxygen atoms with silicon and silicon–nitride surfaces upon N2 injection to the discharge. Our results can be explained by the production of energetic metastable species in the discharge region which transport energy to the gas‐surface interface.

Directional plasma etching of vias and trenches in low dielectric constant insulators during the production of multilevel interconnection schemes presents a rich spectrum of challenges. This is due to the multitude of low dielectric constant materials that are being considered for these applications, and their widely varying properties. We review generic patterning issues for inorganic, organic, and mixed organic/inorganic low dielectric constant materials by presenting a description of process development for several prototypical cases. Fluorocarbon-based etching processes for fluorine-doped SiO2 layers, hydrogen silsequioxane (HSQ), and methyl silsequioxane (MSQ) are discussed and compared with SiO2. More recently, interest in nanoporous silica films has developed since these materials are characterized by a significantly lower dielectric constant than the above SiO2-related materials. The plasma-etching characteristics of the nanoporous silica materials reflect the fact that more polymerization can take place on such surfaces than on conventional SiO2. The differences in behavior depend sensitively on pore size and pore connectivity. For organic dielectrics we describe directional-etching approaches for hydrocarbon- and fluorocarbon-based materials. Oxygen is the primary etching gas for organic materials. Control of the feature profiles is the principal difficulty and can be strongly influenced by the admixing of different gases to O2. Plasma etching of benzocylobutene (BCB) is described as an example of a hybrid material. The chapter concludes with a description of the issues connected with surface-cleaning processes of plasma-exposed metal and/or barrier layers, considerations that are essential to preserving the integrity of the low dielectric constant material during the cleaning step, and a discussion of the issues connected with the extension of cleaning processes to high aspect ratio features.

Below the sub-0.25-/spl mu/m technology range, surface-channel (SC) PMOSFETs employing p+ poly-Si gates are widely used instead of buried-channel (BC) PMOSFETs employing n+ poly-Si gates. However, there are still many advantages of using an n+ poly-Si gate such as the absence of the undesirable Vth shift due to boron penetration through the gate oxide, no gate-dopant cross-diffusion, and process simplicity. The critical issues for extending the use of buried-channel PMOSFETs below the sub-0.25-/spl mu/m technology range, that is, the 4-Gbit DRAM era and beyond, are low Vth and also the suppression of short-channel effects (SCE), which can be achieved by an extremely shallow counter-doped layer with a high impurity concentration. Here, for the first time, we use decaborane (B/sub 10/H/sub 14/) ion implantation to fabricate a 20-nm-thick counter-doped layer and demonstrate an SCE-free high performance O.18-/spl mu/m BC-PMOSFET.

Results of the surface smoothing of a CVD-diamond membrane by gas cluster ion beams are presented. An as-deposited diamond membrane with a surface roughness of 400 A Ra was irradiated by Ar cluster ions with a energy of 20 keV. A very smooth surface of 30 A Ra was obtained at a dose of 3×1017 ions/cm2. This result can be clarified by computer simulation which shows that the surface smoothing of the diamond membrane was improved by a lateral sputtering of the cluster ions. However, a thin graphite layer was formed on the surface by contamination of monomer ions in the cluster beam, which decreased the transparency of the diamond membrane. A subsequent irradiation with O2 cluster ions removed these graphite layers.

Two types of applications in ultra low-energy boron implantation with decaborane (B10H14) molecules for highly miniaturized devices are presented. One is the formation of a 7-nm-deep junction. This ultra shallow junction was applied to a pMOSFET with a gate length of around 50 nm. The other application of this technique is the formation of ultra shallow channels in buried-channel pMOSFETs. We successfully fabricated this type of device, achieving a low threshold voltage and a steep subthreshold.

The development of ultra-high quality (UHQ) films is in progress under the NEDO projects. This project is a collaboration between several companies, national laboratories and universities. A Multi-Beam Gas-Cluster Ion Beam System has been developed for fabricating indium tin oxide (ITO) films. The concept of a multi-beam deposition technique, the description of the Multi-Beam Gas Cluster Ion Beam System as well as our current progress on this project are presented.

The patterning of several novel low dielectric constant (K) materials has been studied in a high-density plasma (HDP) tool. Recent results obtained on oxide-like materials, such as fluorinated oxide, hydrogen silsesquioxane (HSQ), and methyl silsesquioxane (MSQ), are reviewed. These materials can be successfully patterned using a fluorocarbon etching chemistry. The etching is in this case controlled by a thin fluorocarbon film at the surface. The patterning of polymer dielectrics can be performed in an oxygen etching chemistry. As an example, the patterning of Parylene-N in an oxygen chemistry is discussed. In this case, the ion and the oxygen radical flux need to be properly controlled to obtain a directional etching process. After the dielectric etch, either in a fluorocarbon or oxygen based chemistry, fluorocarbons and oxygen contamination remain at the exposed metal surfaces. We recently demonstrated how a plasma treatment following the dielectric etch reduces these contaminants. The results of this treatment on copper surfaces and the resulting modification to the dielectric are reviewed.

We have developed the first ever low-energy, high-dosage boron ion implantation technology using a decaborane (B10H14) molecule. Since B10H14 consists of ten boron atoms, they are implanted with about a one-tenth lower effective acceleration energy and a ten times higher effective beam current compared with those of boron. Using this implantation, we show an ultra-shallow 500 eV boron profile, which do not show transient diffusion after rapid thermal annealing.

The cleaning of Al, TiN, and Cu blanket samples was investigated in a high density inductively coupled plasma reactor, and compared with results for silicon. After simulating the dielectric overetch exposure of these substrates to a CHF3 discharge, an in situ O2 plasma clean and subsequent Ar+ premetal sputter clean were performed and evaluated using ellipsometry and x-ray photoelectron spectroscopy. Following the fluorocarbon exposure, significant C and F residues were observed. Exposure to a O2 plasma clean greatly reduced this contamination. Subsequent treatment with an Ar+ sputter further reduced the thickness of the modified surface layer. Comparisons of the cleaning results with silicon suggest an efficient cleaning procedure, especially in the cases of copper and titanium nitride. The response of several blanket, oxide-like low-K dielectrics to the O2 plasma treatment were also studied and compared to SiO2. While a fluorinated SiO2(SiOF) exhibited SiO2-like stability, deep modifications were observ...

From the starfish Acanthaster planci L. (Acanthasteridae) collected in Ehime Prefecture, Japan, the two new steroid oligoglycoside sulfates 4 and “ape-3” together with a known glycoside sulfate, thornasteroside A (5), have been isolated. The structure of 4 was established as the 3β,6α-dihydroxy-5α-pregn-9(11)-en-20-one 6-O-pentaglycoside 3-O-sulfate corresponding to 5, on the basis of chemical and spectral evidence. For the isolation of glycoside sulfates, reverse phase chromatography could be effectively used. Apart from conventional analytical methods field desorption mass (FDMS) spectrometry was successfully used for the determination and confirmation of the structure of the desulfated glycoside. Biologisch aktive Glycoside aus Asteroidea, II Steroid Oligoglycoside aus dem Seestern Acanthaster planci L., 1 -isolierung und Structure von Oligoglycosid-Sulfate Aus dem Seestern Acanthaster planci L. (Acanthasteridae), der in der Provinz Ehime gesammelt worden war, wurden die beiden neuen Steroid-Oligoglycosid-Sulfate 4 und “Ape-3” sowie ein bekanntes Glycosid-Sulfat, Thornasterosid A (5), isoliert. Auf Grund chemischer und spektroskopischer Untersuchungen wurde die Struktur von 4 als das 5 entsprechende 3β,6α-Dehydroxy 5α-pregn-9(11)-en-20-on-6-O-pentaglycosid-3-O-sulfat identifiziert. Die Isolierung der Glycosid-Sulfate gelang mit Hilfe der Reverse-phase-Chromatographie. Neben den konventionellen analytischen Methoden lies sich die Felddesorptions-(FD-)Massenspektrometrie fur die Bestimmung und Absicherung der Struktur der desulfatierten Glycoside erfolgreich einsetzen

The action of pig pancreas α-amylase on various samples of hydroxyethyl starches (HES) has been studied. It has been shown that the hydrolysis rates of both 2-hydroxyethyl starches (2-HES) and 6-hydroxyethyl starches (6-HES) decreased as M. S. or D. S. increased, i. e. the more the unsubstituted anhydroglucose residues the specimen contained, the more rapidly the degradation took place. Further evidences have been obtained indicating that 2-O-hydroxyethylanhydroglucose residues played a more significant role on the resistance to α-amylase action than 6-O-hydroxyethyl-anhydroglucose residues. Thus, each sample of 2-HES has been more resistant to α-amylolytic attack than the corresponding specimen of 6-HES, regardless of the same content of unsubstituted anhydroglucose residues.

It was found that salmon calcitonin-I (sCT) inhibited in vitro 45Ca2+-uptake by rat brain hypothalamus blocks in a dose-dependent manner. The minimum effective concentration was estimated to be 10 nM or less. The effect appeared to be specific to the hypothalamus and was not observed with the pons plus medulla oblongata or the cerebral cortex. Two C-terminal fragments of the fish hormone, sCT (10-32) and sCT (22-32), and porcine calcitonin failed to inhibit the ion-uptake though tested in concentrations abolishing 125I-sCT binding to these brain tissues, indicating that the whole structure of sCT is essential for the inhibitory effect but not for the binding. Another finding to be noted was a possible dependency of this effect on the integrity of the cell membrane structure. A crude synaptosomal fraction subsequently prepared from sCT-exposed hypothalamus blocks exhibited a decreased uptake of 45Ca2+, while a corresponding fraction from unexposed tissue did not respond to the hormone. These characteristics of this novel in vitro effect of sCT suggest its possible relevancy to the anorectic effect which also appears to be specific to the fish hormone.

During development of the calcitonin binding assay using rat brain particulate fraction, it was noticed that 125l-salmon calcitonin-l (125-SCT) was partly absorbed by the polypropylene tube surface in an irreversible manner. Absorption was partially prevented by cold SCT and complete prevention was achieved by bacitracin. Triton X-100, Brij 36T, and some Zwittergents in such concentration ranges which appeared not to disrupt the 125l-SCT binding ability of brain tissue. The brain fraction itself exhibited a similar preventive effect. The anti-absorbing effect of Brij 36T was also observed in an opiate receptor binding assay for beta-endorphin. These results led us to recommend that the binding assay for these peptides should be done only in the presence of an appropriate anti-absorbant.

From the starfish Acanthaster planci L. (Acanthasteridae) collected in Ehime Prefecture, Japan, the two new steroid oligoglycoside sulfates 4 and “ape-3” together with a known glycoside sulfate, thornasteroside A (5), have been isolated. The structure of 4 was established as the 3β,6α-dihydroxy-5α-pregn-9(11)-en-20-one 6-O-pentaglycoside 3-O-sulfate corresponding to 5, on the basis of chemical and spectral evidence. For the isolation of glycoside sulfates, reverse phase chromatography could be effectively used. Apart from conventional analytical methods field desorption mass (FDMS) spectrometry was successfully used for the determination and confirmation of the structure of the desulfated glycoside. Biologisch aktive Glycoside aus Asteroidea, II Steroid Oligoglycoside aus dem Seestern Acanthaster planci L., 1 -isolierung und Structure von Oligoglycosid-Sulfate Aus dem Seestern Acanthaster planci L. (Acanthasteridae), der in der Provinz Ehime gesammelt worden war, wurden die beiden neuen Steroid-Oligoglycosid-Sulfate 4 und “Ape-3” sowie ein bekanntes Glycosid-Sulfat, Thornasterosid A (5), isoliert. Auf Grund chemischer und spektroskopischer Untersuchungen wurde die Struktur von 4 als das 5 entsprechende 3β,6α-Dehydroxy 5α-pregn-9(11)-en-20-on-6-O-pentaglycosid-3-O-sulfat identifiziert. Die Isolierung der Glycosid-Sulfate gelang mit Hilfe der Reverse-phase-Chromatographie. Neben den konventionellen analytischen Methoden lies sich die Felddesorptions-(FD-)Massenspektrometrie fur die Bestimmung und Absicherung der Struktur der desulfatierten Glycoside erfolgreich einsetzen