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A study of chemisorption of maleic anhydride on Si(100)-2x1 at room temperature is done using scanning tunneling microscopy (STM). A local rearrangement of unsaturated silicon dimers is induced by chemisorption of the organic molecules.

Photovoltaic power plants usually do not provide reactive power output; hence the application of large photovoltaics in power systems will decrease the voltage stability level of the power system. Capacitor banks can provide reactive power to compensate the photovoltaic plants; therefore, capacitor banks can overcome the reactive power deficiency of photovoltaic plants. However, the effect of capacitor bank installation on the system’s voltage stability is unknown. Therefore, the research aims to investigate whether installing a capacitors bank can restore the level of system voltage stability. The study employs the method of Voltage Stability Margin and transient stability simulation to the IEEE 9 bus system. The IEEE 9 bus system is modified where one generator of the system is replaced with a photovoltaic plant, and a capacitor bank is also installed. The study results show that the modified system voltage stability level is lower than the original system. When the capacity of the capacitor bank is increased to the maximum allowable value, the voltage stability level rises. However, it is still unable to be restored to its original value.

Endoliths are more frequently found in extremely harsh environments, but they can inhabit mesic climate and subterranean habitats as well. Whether they are adapted to life inside rocks or do they seek refuge in this way, remains largely unknown for caves and pits. Consequently, subterranean habitats in limestone areas, were explored: three caves in Serbia (Cerjanska, Petnička and Potpeć) and one pit in Croatia (Keranova Golubinka). Sampling of rock substratum containing endoliths was performed at various distances from the entrance, at sites characterized by a lower level of light intensity. Phototrophs were separated from the rock matrix using 10% hydrochloric acid and analyzed using light microscopy. In general, low diversity of endoliths was observed, but representatives from Cyanobacteria, Chlorophyta and Xanthophyta were found. Cyanobacteria, more precisely coccoid forms (genera Aphanocapsa, Chroococcidiopsis, Gloeocapsa, Gloeocapsopsis, Synechococcus), were dominant. The most interesting cyanobacterial taxon, Leptolyngbya-like taxon, representing a true endolith (euendolith), was found in the Petnička Cave. This taxon and its relation to the substratum, as well as chasmoendolithic community from the Keranova Golubinka Pit, were observed using Scanning electron microscopy (SEM). It was observed that chasmoendoliths inhabit already existing surface rock cracks and fissures, while a true endolith actively bores into the substratum. Non-metric multidimensional scaling (NMDS) was performed to observe the similarity between the sampling sites. Endoliths can grow inside the rocks, making them very successful biodeteriogens, which is not a desirable trait for caves and pits that are characterized by various attractive geomorphological features that need to be preserved. Thus, considering these habitats, more attention should be paid to the endolith community in the future.

In this study, we have tested the hypothesis that the expression and secretion of galectins are driven through mechanisms globally impacted by homeostatic regulation involving the post-translational modification of intracellular proteins with O-linked N-acetylglucosamine (O-GlcNAc). We showed that neutrophilic differentiation of HL-60 cells induced by all-trans retinoic acid (ATRA) and 6-diazo-5-oxo-L-norleucine (DON) was associated with a significant drop of cellular O-GlcNAc levels in serum-contained and serum-free cell culture media. Galectin gene and protein expression profiles in HL-60 cells were specifically modified by ATRA and by inhibitors of O-GlcNAc cycle enzymes, however overall trends for each drug were similar between cells growing in the presence or absence of serum except for LGALS9 and LGALS12. The secretion of four galectins (-1, -3, -9, and -10) by HL-60 cells in a serum-free medium was stimulated by O-GlcNAc-reducing ATRA and DON while O-GlcNAc-elevating thiamet G (O-GlcNAcase inhibitor) failed to change the basal levels of extracellular galectins. Taken together, these results demonstrate that O-GlcNAc homeostasis is essential not only for regulation of galectin expression in cells but also for the secretion of multiple members of this protein family, which can be an important novel aspect of unconventional secretion mechanisms.

Dry powder method is a solid-state processing technique involving constant milling of the initial compounds for later calcination. This technique was used to prepare the compounds presented in this essay, using TiO2 and MgO in diferentes rates. To analyze the resulting compounds' morphology, Scanning electron microscope (SEM) was used. In the images taken from the TiO2 sample, groups of agglomerations and of grains were found. Nevertheless, it maintains a certain round pattern in both groups, in the shape of micrograins of 0.5-1 µm. SEM images from the MgO sample are typically laminar with barely a few microns of width. The comparative studies of their structural and spectral characteristics through X-ray Diffraction (XRD) confirmed the individual structure of each compound and also, new spectral lines are obtained which suggests that titanates were formed during the process. [ABSTRACT FROM AUTHOR]

Objectives: To determine the possible impact of El Niño Southern Oscillation (ENSO) on cutaneous leishmaniasis in Sucre, Venezuela, for the 1994-2003 period. Materials and Methods: Climatic data was obtained using remote systems, and it was classified according to the National Oceanograhic and Atmospheric Administration criteria for El Niño, Neutral, or La Niña periods, using the Southern Oscillation Index (SOI) as a variability indicator. Cutaneous leishmaniasis data was obtained from the Environmental Sanitation Management Office in Sucre. Comparisons of annual variations and deviations from average trends were performed for cutaneous leishmaniasis incidence and climatic variability, and regression models were also used. Results: Between 1994 and 2003, 2212 cases of cutaneous leishmaniasis cases were recorded. Three important El Niño phases were observed: 1994-1995, 1997-1998, and 2001-2003, being the one in 1997-1998 the most relevant one, which was followed by a chilly and rainy season in 1999 (La Niña). During 1999-2000, 360 cutaneous leishmaniasis cases were recorded in Sucre, with an important variability within a year, and a 66,7% increase in cutaneous leishmaniasis cases (F= 10,06, p= 0,0051) associated with the presence of a weak La Niña phenomenon (not too cold and rainy). Models showed that with higher SOI values, there was a reduced incidence of cutaneous leishmaniasis (r²= 0,3308; p= 0,0504). The increase with respect to the average trend in rain was associated with increases in trends for cutaneous leishmaniasis in the period from 1994 to 2003 (p= 0,0358). Conclusions: These data reflect the importance of ENSO upon cutaneous leishmaniasis incidence, opening a new research line, with a possible impact on prediction and monitoring, which is relevant for public health. [ABSTRACT FROM AUTHOR]

Galectins are a family of soluble β-galactoside-binding proteins with diverse glycan-dependent and glycan-independent functions outside and inside the cell. Human cells express twelve out of sixteen recognized mammalian galectin genes and their expression profiles are very different between cell types and tissues. In this review, we summarize the current knowledge on the changes in the expression of individual galectins at mRNA and protein levels in different types of differentiating cells and the effects of recombinant galectins on cellular differentiation. A new model of galectin regulation is proposed considering the change in O-GlcNAc homeostasis between progenitor/stem cells and mature differentiated cells. The recognition of galectins as regulatory factors controlling cell differentiation and self-renewal is essential for developmental and cancer biology to develop innovative strategies for prevention and targeted treatment of proliferative diseases, tissue regeneration, and stem-cell therapy.

Three new troglobitic leiodid beetle species have been described from several underground habitats in Central Bosnia and Herzegovina: Leonhardia jajcensis sp. n., from the Kapnica Cave, village of Božikovac, near Jajce, Mt. Dnolučka Planina, Katobatizon apfelbecki sp. n., from the Jama Ispod Puta, village of Božikovac, and the Snježara Pits, village of Brvanci, near Jajce, Mt. Dnolučka Planina, and Protobracharthron dusinae sp. n., from the Dusina Cave, village of Dusina, near Fojnica, Mt. Pogorelica. The three leiodid species are easily distinguished from related taxa. All important morphological characteristics of the species have been listed, along with the diagnoses and images of the taxa. The new species are relicts and endemics of Central Bosnia and Herzegovina and probably belong to old phyletic lineages of Tertiary or even pre-Tertiary origin. [Projekat Ministarstva nauke Republike Srbije, br. 173038]

A new blind false scorpion, Microchthonius kasteli n. sp., from the Mićoletova Jama Pit, Rudine, nr. Kaštel, Dalmatia, has been described. The new pseudoscorpion is different from all other congeners. It is probable that this new taxon is the remain of an old tropical soil fauna, which now inhabits the subtropical area of the Mediterranean seaside. Morphometric ratios, figures, and linear measurements of the new species are presented in detail. [Projekat Ministarstva nauke Republike Srbije, br. 173038]

A careful analysis of samples of pseudoscorpions (Neobisiidae, Pseudoscorpiones) from two underground habitats, one near Trebinje (Herzegovina) and the other from the National Park Paklenica (Croatia), has yielded two species of the genus Roncus L. Koch new to science, Roncus tribunus n. sp. and R. argyrunti n. sp. Both new species are described thoroughly, illustrated, and diagnosed. Some biogeographical and evolutionary characteristics of the two taxa are briefly discussed. [Projekat Ministarstva nauke Republike Srbije, br. 173038]

New faunistic and taxonomic data for the species: Sulcia oculata Kratochvil, 1938, Thyphlonesticus absoloni (Kratochvil, 1934), Centromerus serbicus Deltshev, 2003, Palliduphantes spelaeorum (Kulczyński, 1914) and Porrhomma convexum (Westring, 1851), found in the caves of Bosnia, Montenegro and Serbia are presented. Photos of the male palps and epigynes of the species S. oculata. T. absoloni and C. serbicus, are published for first time.

A new species of troglobitic false scorpion, Roncus bosniensis n. sp. (Neobisiidae, Pseudoscorpiones), is described from inside an underground habitat, the Jama Pored Puta Pit, nr. Jajce, Bosnia and Herzegovina. The analyzed pseudoscorpion proves to differ from all other congeners, but is closest to R. hajnehaj Ćurčić & Dimitrijević. It is possible that the subterranean pseudoscorpion analyzed represents a relict of an old tropical faunal pattern of the Mediterranean. [Projekat Ministarstva nauke Republike Srbije, br. 173038]

A new endemic pseudoscorpion species from the Jama Pit nr. Daorson, Stolac, Southeastern Bosnia and Herzegovina, is presented, thoroughly described and illustrated. It is named Chthonius (Globochthonius) daorsoni n. sp. Its main morphometric characters and important diagnostic features are analyzed and compared to those of its phenetically and phylogenetically closest congeners.

A new endogean bembidiine ground beetle species, Winklerites serbicus sp. n., from a cave in the southeastern part of Serbia is both described and diagnosed. Male and female genital structures and other taxonomically important characters are illustrated. The new species is clearly distinct from its closest congeners. Fifteen species of the genus so far known are arranged in six groups. The new species is both endemic and relict, inhabiting southeastern Serbia only. [Projekat Ministarstva nauke Republike Srbije, br. 173038 i br. 47007]

The cave-dwelling forms of the genus Neobisium L. koch comprise many phyletic lines, some less specialized and others highly adapted to cave life. To trace their origin, biogeography and evolution, it is necessary to compare the evidence about troglobitic species with that of the epigean forms from different European habitats, especially in the Mediterranean or Dinaric regions. In this study, descriptions of Neobisium crucis n. sp. and N. pluzinensis n. sp., both from caves in Montenegro, are presented, with some details on the comparative morphology and morphometric ratios. [Projekat Ministarstva nauke Republike Srbije, br. 173038]

Five years ago, Ćurčić et al. (2008) described two new pseudoscorpions: Roncus diocletiani Ćurčić, Dimitrijević and Rađa (from Croatia) and R. orjensis Ćurčić, Dimitrijević and Rađa (from Montenegro). The pseudoscorpions studied were mounted on slides with gum-chloral medium. They are deposited in the collection of the Institute of Zoology, Faculty of Biology, University of Belgrade, 11000 Belgrade, Serbia and in the collection of the Natural History Museum, 21000 Split, Croatia. It has been shown that only the male of R. diocletiani belongs to the nominal species, while the female of the same taxon belongs to Archaeoroncus tenuis (Hadži). Therefore, the “allotype male” of R. diocletiani is actually a holotype of this species, while the “holotype” of R. diocletiani becomes a paratype of A. tenuis. [Projekat Ministarstva nauke Republike Srbije, br. 173038]

A new eyeless pseudoscorpion, Microchthonius tragurion n. sp., from a cave in Blizna Donja (near Trogir), from the Jama kod Gomilje Pit, Dalmatia, is described. This new false scorpion differs from all other congeners. There exists a probability that this new taxon is a relict of a tropical fauna incorporating the once northern and tropical area, now representing the subtropical part of the Mediterranean. Morphometric ratios, figures and linear measurements of the new taxon are presented in detail. [Projekat Ministarstva nauke Republike Srbije, br. 173038]

Two new polydesmid species are described, illustrated, and diagnosed: a troglobitic, Brachydesmus mulaomerovici n. sp., from Bosnia and Herzegovina and epigean Brachydesmus verrucosus n. sp. from Macedonia. The new taxa belong to inferus- and stygivagus-groups of species, respectively. Relationships with congeners are briefly discussed. The distribution map and key are given for all currently known taxa belonging to these groups of species. [Projekat Ministarstva nauke Republike Srbije, br. 173038]

A new eyeless false scorpion, Microchthonius elegantissimus n. sp. from inside an underground (cave) system, i.e. Jama Golubinka u Kalaševin Dugin Njivaman Cave (= Kalaševa Jama Pit), Kladnjice, Croatia, is described. This new pseudoscorpion differs from all other congeners. There exists a probability that the new false scorpion belongs to relicts of an old tropical area incorporating the northern subtropical part of the Mediterranean. Morphometric ratios, linear measurements and figures of the taxon are presented in detail.

Two new endemic species from the Jama Bezdan Pit between the villages of Komaji and Vignje, southeast from Ćilipi and Dubrovnik, Dalmatia (Croatia) - Chthonius (Chthonius) croaticus n. sp. B. Ćurčić & Rađa (Chthoniidae) and Roncus ragusae n. sp. B. Ćurčić & Rađa (Neobisiidae), are herein erected, described and thoroughly illustrated. Their main morphometric features and important diagnostic characters are analyzed and compared to their closest congeners, Chthonius (Chthonius) pristani Ćurčić and Roncus podaga Ćurčić, respectively. [Acknowledgments. This study is financially supported by the Serbian Ministry of Education and Science (Grant 173038).]

The pseudoscorpion sample discovered under a stone in Dalmatia (Croatia) was studied. A new species is described herein: Chthonius (Chthonius) makirina n. sp. This taxon is considered endemic to Dalmatia and the Balkan Peninsula. Along these lines, the diagnostic characters of the analyzed species are thoroughly described and figured. Taxonomic interrelationship and geographic distribution are briefly discussed.

An analysis of the pseudoscorpion material from Croatia has supported the elevation of two taxa to full species rank: Chthonius (Chthonius) pagus n. sp. and Roncus navalia n. sp., both from Dalmatia; Croatia. Most diagnostic characters of the analyzed species are thoroughly described or figured. Some taxonomic interrelationships and features of geographic distribution have also been briefly discussed. Both studied taxa, which currently inhabit a cave on the Island of Pag in Dalmatia (Croatia), are probably endemics and relics of the Tertiary period. [Projekat Ministarstva nauke Republike Srbije, br. 173038]

Two species of troglobitic false scorpions, Roncus meledae n. sp. and Neobisium oculatum n. sp. (Neobisiidae, Pseudoscorpiones), are described from inside underground habitat, i.e. the Jama Na Žutim Kokom Cave, the Island of Mljet, Dalmatia, Croatia. The analyzed pseudoscorpions prove to differ from all other congeners. It is possible that the subterranean pseudoscorpions analyzed represent relicts of an old north tropical faunal pattern of the Mediterranean. [Projekat Ministarstva nauke Republike Srbije, br. 173038]

A new genus (Punctoduvalius gen. n.) and a species of trechine ground beetles (Punctoduvalius orlovacensis sp. n.) from Bosnia and Herzegovina have been described and diagnosed. Punctoduvalius gen. n. is clearly distinct from all other phenetically close genera in many important respects, such as: the presence of depigmented reduced eyes, the presence of a pigmented eye border, the presence of deep and complete frontal furrows, the presence of tiny setae on the genae, the presence of distinct longitudinal fissures on the protibias, the ratio of length/width of the first protarsal article in males, the presence of two elytral discal setae, the presence of numerous setiferous punctures in interstrial spaces, the specific position of the humeral setae, and the specific shape of the copulatory piece. This new genus comprises four species: Punctoduvalius pilifer (Ganglbauer, 1891) (endogean from Mts. Treskavica and Bjelašnica, and from a cave on Mt. Visočica, Bosnia and Herzegovina), P. protectus (Winkler, 1926) (from the Pećina kod Ostojića Cave, Mt. Treskavica, and endogean from Mt. Jahorina, Bosnia and Herzegovina), P. brevipilosus (Knirsch, 1927) (endogean from Lupoglav Peak, Mt. Prenj, Bosnia and Herzegovina), and P. orlovacensis sp. n. (from the Orlovača Cave, village of Donje Biševo, near Pale, Bosnia and Herzegovina). The four species clearly differ in many important respects. The following three taxonomic changes are proposed: Punctoduvalius pilifer (Ganglbauer, 1891), comb. n., P. protectus (Winkler, 1926), comb. n., and P. brevipilosus (Knirsch, 1927), comb. n. The new genus and its members belong to an old separate phyletic lineage, distinct from all other existing species groups. Additionally, these forms are relict and endemic to the deep soil and caves of Bosnia and Herzegovina. [Acknowledgments. This study was financially supported by the Serbian Ministry of Education and Science (Grant No. 173038).]

A new leptodirine leiodid beetle species, Parapropus vitorogensis sp. n., from a cave in the western part of the Republic of Srpska, Bosnia and Herzegovina, is described and diagnosed. Both male and female genitalia and other taxonomically important characters are illustrated. The new species is clearly distinct from its closest congeners. The new taxon is of Tertiary or even pre-Tertiary age and originated during the Alpine Orogeny that affected vast areas of the Balkan Peninsula, including the Dinarides, its terra typica. The new species is both endemic and relict, inhabiting western Bosnia and Herzegovina only. [Projekat Ministarstva nauke Republike Srbije, br. 173038 and br. 47007]

The pseudoscorpion sample from a cave in Bosnia has been studied. Two new species have been described herein: Chthonius (Chthonius) protobosniacus n. sp. and C. (C.) kladanjensis n. sp. Both taxa are considered endemic of Bosnia and the Balkan Peninsula. In this paper, diagnostic characters of the analyzed forms are thoroughly described and figured. Taxonomic interrelationship amd geographic distribution are briefly discussed.

A new species of epigean pseudoscorpion pertaining to the genus Chthonius C. L. Koch 1843 from Macedonia is erected. Its relationship to phenetically close congeners is briefly discussed. The new species, Chthonius (Ephippiochthonius) lagadini n. sp. is a relict form presently known only from its type locality (Lagadin, nr. Ohrid, Macedonia).

A new pseudoscorpion from the family Chthoniidae - Chthonius (Chthonius) aquasanctae n. sp. from west Serbia is described. The newly erected taxon is endemic to the area studied. Its taxonomic relationship to its phenetically close congeners Chthonius (Chthonius) lesnik Ćurčić and Chthonius (Chthonius) iugoslavicus Ćurčić, as well as the comparative morphological traits, are described in detail.

A new cave-dwelling pseudoscorpion from the Badanj (or Vilišnica) Cave, nr. Sveti Filip i Jakov, Dalmatia (Croatia) is thoroughly described and illustrated. Its main morphometric characteristics and important diagnostic traits are analyzed and compared to those of its phenetically close congener Chthonius (Chthonius) absoloni Beier from Dalmatia. The new species is relict and endemic to the area studied.

Two new epigean pseudoscorpion species belonging to the family Chthoniidae - Chthonius (Ephippiochthonius) metohicus n. sp. and Chthonius (Ephippiochthonius) civitatisveti n. sp. from the UN Administered Province of Kosovo and Southern Croatia, respectively, are described. The newly erected taxa are endemic to each of the areas studied. Their taxonomic relationship with their phenetically close congeners Chthonius (Ephippiochthonius) bidentatus Beier, 1939, Chthonius (Ephippiochthonius) kemza Ćurčić, Lee et Makarov, 1993 and Chthonius (Ephippiochthonius) tetrachelatus (Preyssler, 1790) and comparative morphological traits are described.

Two new endemic cave pseudoscorpion species from the Petropavlova Pećina Cave, village Bihovi, 6 km from Trebinje, Herzegovina, are presented, thoroughly described and illustrated. These are named Chthonius (Globochthonius) petroupauli n. sp. and Roncus paulipetrou n. sp. Their main morphometric characteristics and important diagnostic features are analyzed and compared to those of their phylogenetically closest congeners.

Three new species of the pseudoscorpion genus Roncus L. Koch (Neobisiidae) are described from Croatia (from nr. Omiš, Dalmatia: R. almissae n. sp.) and Serbia (near the town of Krupanj, north-western Serbia, Lukića Pećina Cave and nr. Izvor: R. krupanjensis n. sp., and R. radji n. sp.), and their diagnostic characteristics are illustrated. Their interrelations with phenetically close congeners are analyzed; in addition, the presence/absence of microsetae proximal to the trichobothria eb and esb is established as an important taxonomic characteristic.

A new epigean pseudoscorpion, Chthonius (Chthonius) onaei n. sp. is erected from Podašpilje, nr. Omiš, Mt. Omiška Dinara, Dalmatia, Croatia. Its interrelations with two close congeners, Chthonius (C.) litoralis Hadži, 1933 and Chthonius (C.) dalmatinus Hadži, 1930 are briefly discussed.

A careful analysis of samples of pseudoscorpions (Neobisiidae, Pseudoscorpiones) from two epigean habitats, one near Split (Croatia) and the other on Mt. Orjen (Montenegro), has yielded two species of the genus Roncus L. Koch new to science: Roncus diocletiani n. sp. and R. orjensis n. sp. Both new species are described, thoroughly illustrated, and diagnosed. Some biogeographical and evolutionary characteristics of the two taxa are briefly discussed.

A new species of the endemic pseudoscorpion genus Protoneobisium Ćurčić, 1988, P. basilice sp. n. from Croatia has been found, described and diagnosed. From its phenetically close congener, P. biocovense (Müller, 1931), the new taxon differs in many respects of both qualitative and quantitative nature. Both species of Protoneobisium have a limited distribution; they inhabit Mt. Biokovo, Croatia, and are probably the remnants of some ancient Maditerranean fauna of pre-Tertiary origin.

Abstract Background The corpus luteum (CL) is a transient endocrine gland and prostaglandin F2-alpha is considered to be the principal luteolysin in pigs. In this species, the in vivo administration of prostaglandin F2-alpha induces apoptosis in large vessels as early as 6 hours after administration. The presence of the prostaglandin F2-alpha receptor (FPr) on the microvascular endothelial cells (pCL-MVECs) of the porcine corpus luteum has not yet been defined. The aim of the study was to assess FPr expression in pCL-MVECs in the early and mid-luteal phases (EL-p, ML-p), and during pregnancy (P-p). Moreover, the effectiveness of prostaglandin F2-alpha treatment in inducing pCL-MVEC apoptosis was tested. Methods Porcine CLs were collected in the EL and ML phases and during P-p. All CLs from each animal were minced together and the homogenates underwent enzymatic digestion. The pCL-MVECs were then positively selected by an immunomagnetic separation protocol using Dynabeads coated with anti-CD31 monoclonal antibody and seeded in flasks in the presence of EGM 2-MV (Microvascular Endothelial Cell Medium-2). After 4 days of culture, the cells underwent additional immunomagnetic selection and were seeded in flasks until the confluent stage. PCR Real time, western blot and immunodetection assays were utilized to assess the presence of FPr on pCL-MVEC primary cultures. Furthermore, the influence of culture time (freshly isolated, cultured overnight and at confluence) and hormonal treatment (P4 and E2) on FPr expression in pCL-MVECs was also investigated. Apoptosis was detected by TUNEL assay of pCL-MVECs exposed to prostaglandin F2-alpha. Results We obtained primary cultures of pCL-MVECs from all animals. FPr mRNA and protein levels showed the highest value (ANOVA) in CL-MVECs derived from the early-luteal phase. Moreover, freshly isolated MVECs showed a higher FPr mRNA value than those cultured overnight and confluent cells (ANOVA). prostaglandin F2-alpha treatment failed to induce an apoptotic response in all the pCL-MVEC cultures. Conclusion Our data showing the presence of FPr on MVECs and the inability of prostaglandin F2-alpha to evoke an in vitro apoptotic response suggest that other molecules or mechanisms must be considered in order to explain the in vivo direct pro-apoptotic effect of prostaglandin F2-alpha at the endothelial level.

High-resolution electron energy loss spectroscopy and photoluminescence measurements have been used to follow the formation of gap states during the initial oxidation of Si(100)-2x1 at room temperature. We find strong indications that gap states are already induced after the adsorption of 0.002 L of molecular oxygen on Si(100)-2x1. It is demonstrated that prolonged exposures of clean and dehydrogenated oxide films on Si(100) to H[sub 2]O at room temperature decrease the density of gap states significantly. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]