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We present the data records and station history of an automatic weather station (AWS) on Denali Pass (5715 m MSL), Alaska. The station was installed by a team of climbers from the Japanese Alpine Club after a fatal accident involving Japanese climbers in 1989 and was operational intermittently between 1990 and 2007, measuring primarily air temperature and wind speed. In later years, the AWS was operated by the International Arctic Research Center of the University of Alaska Fairbanks. Station history is reconstructed from available documentation as archived by the expedition teams. To extract and preserve data records, the original datalogger files were processed. We highlight numerous challenges and sources of uncertainty resulting from the location of the station and the circumstances of its operation. The data records exemplify the harsh meteorological conditions at the site: air temperatures down to approximately −60°C were recorded, and wind speeds reached values in excess of 60 m s−1. Measured temperatures correlate strongly with reanalysis data at the 500-hPa level. An approximation of critical wind speed thresholds and a reanalysis-based reconstruction of the meteorological conditions during the 1989 accident confirm that the climbers faced extremely hazardous wind speeds and very low temperatures. The data from the Denali Pass AWS represent a unique historical record that can, we hope, serve as a basis for further monitoring efforts in the summit region of Denali.

An overview of climatological and meteorological conditions and their seasonal variability in the Denali summit region is presented, based on the NCEP–NCAR reanalysis 1 dataset for the 1948–2018 period. At the Denali grid cell, a warming trend of +0.02°C significant at the 95% level is found—equivalent to a temperature increase of 1.4°C over the time period. The number of very cold days (−1) during the climbing season also shows a decreasing trend for the majority of the time series. To assess synoptic patterns that affect the Denali region, a self-organizing map algorithm was applied to the geopotential height (GPH) field extracted from the reanalysis data. In winter, the synoptic situation in the Denali region is dominated by frequent zonal flow and negative GPH anomalies associated with the polar front. As the polar front moves north during the seasonal cycle, patterns shift to largely positive GPH anomalies and more meridional flow. Extreme wind speeds unfavorable for climbing occur in all seasons and are associated mainly with the polar jet passing directly over Denali, or cyclogenesis in the Bering Sea. The frequency of occurrence of strongly zonal, low GPH patterns during the main climbing season (April–July) shows a slight decrease in recent years.

We aimed to clarify the relationship between oral function assessments regarding oral hypofunction and sarcopenia in patients who had completed treatment for organic dental problems, including oral pain, removable denture fit, and tooth loss. This cross-sectional study included 269 patients aged ≥65 years (mean age 74.9 ± 6.50 years, 133 men, 136 women) who visited a dental clinic between June 2019 and March 2021. We evaluated oral function and sarcopenia and analyzed their relationship using the Jonckheere–Terpstra test, Mantel–Haenszel trend test, and Poisson regression analysis. We diagnosed 132 (49.07%) patients with oral hypofunction, 30 (11.2%) with sarcopenia, and 24 (8.9%) with severe sarcopenia. The number of oral hypofunction items (prevalence rate ratio [PRR] = 1.39, 95%Wald = 0.11 to 0.56) was significantly associated with sarcopenia. For each of the items, tongue-lip motor function [ta] (PRR = 0.80, 95%Wald = −0.44 to −0.02)] [ka] (PRR = 0.76, 95%Wald = −0.53 to −0.03) and tongue pressure (PRR = 0.95, 95%Wald = −0.09 to −0.02) showed a significant association with sarcopenia. However, no significant association was found for other variables. Dentists should not only treat organic dental problems but also consider the relationship between oral function and sarcopenia.

The liver is the most common site for recurrent metastases from bile duct cancer (BDC) in the ampullary area. However, the optimal chemotherapy regimen for recurrent hepatic metastases has not yet been established. An oral combined fluoropyrimidine drug, S-1 (tegafur, gimeracil and oteracil), has recently been introduced alone or in combination with gemcitabine for BDC. A 67-year-old man underwent a pancreaticoduodenectomy (PD) for early stage distal BDC in the ampullary area. A small hepatic metastasis developed 8 months after the PD. Combined chemotherapy of S-1 (80 mg/m(2)) and gemcitabine (1000 mg/m(2)) was started after radiofrequency ablation (RFA) of the hepatic tumor. Although complete response was achieved and maintained for 4 months with chemotherapy, there was regrowth of the tumor. We performed hepatic segmentectomy for radical treatment. Fourteen months after the hepatectomy, metastasis developed again in the remnant liver. Bevacizumab was added to the combination chemotherapy with S-1 and gemcitabine, since the cancer seemed resistant to the chemotherapy alone. The patient has been well managed for 3 years by a multidisciplinary treatment with surgery, RFA and the combination chemo-therapy on an outpatient basis. This case indicates that distal BDC even in an early stage has a more malignant potential than anticipated. The multidisciplinary treatment including surgery, RFA and combination chemotherapy of S-1, gemcitabine and bevacizumab was effective for BDC with hepatic metastasis. This chemotherapy is feasible on an outpatient basis and may be one of the treatment options for metastatic BDC.

The reduction of sulfur content in gasoline and diesel fuel is a great environmental concern to reduce the motor vehicle emissions. Oxidative desulfurization using acetonitrile biphasic system has received much attention in recent years. The oxidative desulfurization can be oxidized the unreactive sulfur contents in the hydrodesulfurization and removed effectively. For the oxidative desulfurization process design and development, liquid–liquid equilibria (LLE) for acetonitrile biphasic systems are needed as fundamental information. In our previous work, LLE for acetonitrile + n-octane and + n-decane systems have been reported. In this work, therefore, LLE for acetonitrile + n-hexadecane system was measured. Furthermore, NRTL equation was applied to correlate the LLE for these three acetonitrile + n-alkane systems.

Sjogren's syndrome (SS) is uncommon in men and there are few reports that describe their clinical features. In the present study, we investigated salivary gland manifestations in men with SS and compared the results with those in women patients. This study included 12 men and 117 women with SS, and the mean stimulated parotid flow rate in men (4.1 ml/5 min, n = 10) was higher than that of the women (3.1 ml/5 min, n = 101). The prevalence of SS-related sialographic findings, such as globular and punctate sialectasis, was significantly (P

An apparatus has been developed for the measurement of mutual miscibility temperatures of binary liquid mixtures coexisting with a high pressure gas to examine to what extent the phase behavior changes. Methanol + hydrocarbon (cyclohexane, hexane, octane, and decane) binary mixtures were selected as typical polar and non-polar mixtures. And their mutual miscibility temperatures were measured at temperatures from 275.4 to 363.9 K and pressures up to 2.2 MPa with pressurized carbon dioxide (CO2). The experimental results were correlated with the NRTL equation by adopting a pseudo-binary mixture treatment. The NRTL interaction parameters between methanol and hydrocarbons were assumed to vary due to the presence of CO2. A good agreement between the experimental and the correlated mutual miscibility temperatures is obtained.

An investigation was carried out of the factors influencing the toughness of flash welded high strength steel plate.1 It was explained that the major factors for toughness degradation can be summarised by the following: there is an inclusion factor, that is oxides which remain at the weld interface and act as the starting point for fracture and the inclusions within steel which tend to be parallel to the weld interface due to metal flow; there is a microstructural factor, that is degradation of the microstructure due to coarsening of former g grains, a localised softened layer at the weld zone centre and the texture formed where there has been heavy rolling. Consequently, in order to secure toughness, a reduction of oxides at the weld interface and an improvement of steel material purity are required for the former case and the post weld heat treatment is required for the latter.

(2004). Factors affecting flash weldability in high strength steel – a study on toughness improvement of flash welded joints in high strength steel. Welding International: Vol. 18, No. 6, pp. 436-443.

For the purpose of improving the toughness of flash weld, the effect of upsetting conditions on the flash weld of 980MPa grade high strength steel bar has been studied. The main results obtained are as follows; (1) Characteristic features have been observed in the displacement profile when the upsetting condition is set to higher current and lower pressure during upsetting. In case of higher current conditions, the upsetting speed increases rapidly and then goes down in a short time, which phenomena is repeated several times until its upsetting process is finished. (2) According to high-speed camera observation, such rapid increase in the upsetting speed is attributed to the extrusion of molten metal layer formed at the weld interface due to excessive joule heating. The specimens showing the melting-extruding upsetting phenomena have revealed superior weld toughness rather than those produced by conventional upsetting conditions. (3) The reason of toughness improvement in the high current condition where the melting and extruding upsetting mode is observed is considered to be the extrusion of both oxides defects and base metal inclusions, and the achievement of small upset deformation due to the lower upsetting pressure.

A newly developed laser light scattering technique was tested for the determination of cloud-point curves in polystyrene+cyclohexane and in polystyrene+methyl acetate systems at moderate pressures. The solubility data were determined for molecular weights of polystyrene of M ×10 −4 =9.0 and 19.0 for the cyclohexane system, and of M ×10 −4 =70.6 for the methyl acetate system at temperatures up to upper critical solution temperature. The experimentally determined cloud points were satisfactory correlated by Flory type models.

We retrospectively studied 167 patients with oral squamous cell carcinoma (SCC) who were treated at our department from 1984 through 1994 to evaluate the effect of preoperative radiotherapy on outcome. Analyses were performed with Cox's proportional hazards model. Forty-five patients received preoperative radiotherapy with a mean dose of 39.0 Gy (R+S group), and the remaining 122 patients underwent surgical excision without radiotherapy (S group). These groups differed significantly with respect to the distribution of age, T and N categories, histological grade according to the World Health Organization (WHO) criteria, and mode of invasion as proposed by Yamamoto and Kohama. There was a significant negative correlation between the 5-year cumulative survival rate and N category, WHO grade, and mode of invasion. We also investigated the relationship of outcome to N category, WHO grade, mode of invasion, and treatment (between the R+S and the S groups) by Cox's proportional hazards model. Hazard ratios (weight of prognostic factors) were 3.31 (p

Flow cytometric analysis of cell cycle fractions and DNA ploidy was performed on 39 biopsy specimens of oral leukoplakia. The aneuploidy rate of these leukoplakias was 9/39 (23.1%) and the mean DNA index of the aneuploid lesions was 1.34. The aneuploidy rate was significantly higher in severely dysplastic lesions (8/17) than in mildly dysplastic (1/15, P

A newly developed laser light scattering technique was used for the determination of mutual solubilities in the aniline+cydohexane system at moderate pressures. The liquid-liquid equilibria (LLE) were measured from the region of solid-liquid equilibria (SLE) to the upper critical solution temperature. Freezing points in this system were determined by a cooling curve method. The solubility data were correlated with the NRTL equation.

An alternative synthesis of 3, 9-dimethyl-8-oxoadenine (N6-demethylcaissarone) hydrochloride (5a·HCl) starting from 9-methyl-8-oxoadenine (17) is described. The synthesis proceeded through N(7)-benzylation, N(1)-oxidation, and O-benzylation to afford the 1-benzyloxy derivative 25, which afforded the ring-opened formamide derivative 26 on treatment with dilute aqueous NaOH. Methylation of the monocycle 26 with MeI in the presence of K2CO3, followed by acid-catalyzed cyclization and subsequent catalytic hydrogenolysis afforded 5a·HCl. The key intermediate 25 was alternatively prepared from 17 by N-oxidation and subsequent O, N(7)-dibenzylation with PhCH2Br in the presence of K2CO3.

Summary This paper deals with the resistance spot weldability of steel to aluminium alloy using an intermediate layer of aluminium clad steel. Five types of clad sheet with various steel/aluminium thickness ratios were produced by hot rolling. The mechanical properties of the clad sheet changed with the thickness ratio and ranged between those of steel and:those of aluminium sheet. The peel strength of the steel/aluminium interfaces was greater than 25 N/mm. Materials used in spot welding were 0.8 mm thick EDDQ steel sheet, three types of 1.0 mm thick aluminium alloy sheet and the clad sheet mentioned above. Spot‐weldability, including suitable welding current, nugget diameter, tensile shear strength and thickness of the intermetallic compound layer formed at the interface of the clad sheets, changed with the thickness ratio of the clad sheet. From these results, it was concluded that spot‐weldability was affected by the thickness ratio of the clad sheets. Spot‐weldability was also affected by the alloyin...

When discussing the aerodynamic stability of a structure, in-depth knowledge of characteristics of wind prevailing at the site where the structure is to be erected constitutes an engineering input of vital importance to adding substance to the discussion.In other words, the construction site wind condition varies with locations from the effects of surrounding topographical features. Therefore, even the structeres of indentical design, when constructed in different locations, demand different engineering considerations as regards the wind resistance capability or vibration control measurs.In addition, take onestructure and the exposureto wind is not necessarily uniform over its entire surfaces. Also, the wind effects can totally differ depending on the wind direction.This paper reviews a series of studies conducted by the authors on the effect of topography on natural wind and consequent structure responses to wind excitation focusing on some particular types of structure chosen as typical examples. The characteristics of winds of winds blowing over the hill top.small islands, or through the channel or strait, were examined and the effects of natural winds deflected by these topographical features on the structures analyzed by such wind effects prediction techniquse as the observational survey, relief map wind tunnel testing, computerized tecnique of computational fluid dynamcs (CFD), etc.

Summary This paper describes an investigation of the effects of the chemical composition of the base material on the quality of flash welds. Bending tests of welds were run for 43 types of steel sheets, including solution‐strengthened, precipitation‐strengthened, and complex structure‐strengthened (dual‐phase) high‐strength steels up to 590 MPa. A fractographic analysis showed cracks at the weld interface to be caused by oxide inclusions. Aluminium, silicon, and manganese are the major constituents of the inclusions, and the relative intensity of effect of these elements broadly has an Al:Si:Mn = 10:1:0.01 sequence. Carbon is also shown to affect interface cracking by reducing weld ductility. An equivalent formula is experimentally established to determine the effects of these elements on interface cracking. The ordinary bending test is shown to be a simple and reliable method for quantitative evaluation of the interface quality of flash welds, with the notch bending test being more effective for evaluati...

A newly developed laser scattering technique was tested for the determination of mutual solubilities in the 2-butanol + water system at moderate pressures. The liquid−liquid solubility data were measured from the region of solid−liquid equilibria to the upper critical solution temperature. Freezing points in this system were determined by a cooling curve method. A concave curvature of the liquid−liquid line was observed in the vicinity of the freezing points. The solubility data were satisfactorily correlated with Hiranuma's modification of the Wilson equation. The newly measured data compare favorably with previous measurements.

We studied 13 male cases of Sjogren's syndrome (SS). The incidence of periductal lymphocytic infiltration of the labial glands, parotid glands, or both in the male cases was 18%(2/11), which was significantly (P

Summary This paper describes an investigation of the resistance spot weldability of aluminium clad steel sheet to steel or aluminium sheet as well as joining of a steel to an aluminium sheet with an aluminium clad steel sheet as an intermediate layer. The clad steel sheet was produced by hot‐rolling of steel and aluminium sheet by a direct resistance heating process. The mechanical properties of the clad steel sheet were between those of the steel and aluminium sheet, and the peel strength was satisfactorily high. The materials used in spot welding were a 0.8 mm thick EDDQ steel sheet, a 1.0 mm thick aluminium‐magnesium alloy sheet, and a 0.8 mm thick clad steel sheet which had an aluminium/steel thickness ratio of 1.1:1. Spot welding of steel sheet to the steel side of the clad steel sheet and aluminium sheet to the aluminium side of the clad steel sheet was successful. Spot welding of steel sheet to aluminium sheet using the clad steel sheet as an intermediate layer was also successful. The spot welding...

A detailed account is given of the first unequivocal synthesis of adenine 7-oxide (8). The synthesis started with peroxycarboxylic acid oxidation of 3-benzyladenine (6), readily obtainable from adenine (1) by benzylation, and proceeded through nonreductive debenzylation of the resulting 3-benzyladenine 7-oxide (7). The location of the oxygen function in 7 and 8 was confirmed by their chemical reactions including deamination and methylation and by X-ray crystallographic analysis. A UV spectroscopic approach suggested that the neutral species of 8 exists in H2O as an equilibrated mixture of the N(7)-oxide (8) and N(7)-OH (21) tautomers. Treatment of 6 with 30% aqueous H2O2 in MeOH in the presence of MeCN and KHCO3 at 30°C produced the N(7)-oxide 7 and 7-acetamido-3-benzyladenine (15) in 12% and 1% yields, respectively.

Influence of chemical elements of base material has been investigated on interface quality of flash weld. Bend test of welds was carried out for 43 kinds of sheet steels which included solid solution strengthened, dual phase and precipitation hardened high strength steels up to 590 MPa.Fractography anlysis indicated that cracks at weld interface were caused by oxide inclusions. Aluminum, silicon and manganese were major elements of the inclusion, and whose influence were determined to be strong as 10:1:0.01 in the order. Carbon was also proved to affect cracking at interface by reducing ductility of weld. Equivalent formula was experimentally established for the influence of those elements on interface cracking.The ordinary bend test was proved to be used as a simple and reliable method in quantitative evaluation of the interface quality of flash weld, while notch bend test showed higher ability in the evaluation than that.

In contrast to the N(3)-selectivity in N-alkylation, N-oxidation of 7-benzyladenine (17) with m-chloroperoxybenzoic acid in MeOH has been found to give 7-benzyladenine 1-oxide (18) in 76% yield. Alternatively, the same N-oxide (18) has been synthesized in 81% yield from 1-benzyl-4-(ethoxymethyleneamino)imidazole-5-carbonitrile(19) and hydroxylamine. Treatment of 1-benzyl-4-(hydroxyamino)imidazole-5-carbonitrile (24), obtained in 63% yield from the corresponding 4-nitro drivative (20) by catalytic hydrogenation (Pt/H2), with formamidine acetate in boiling EtOH furnished 7-benzyladenine 3-oxyde (23) in 78% yield. A UV spectroscopic approach indicated that the neutral species of 18 exists in H2O in the N(1)-oxide form rather than the N(1)-OH form (27).

Initial stage of upset was investigated. The welding machine for experiment was designed so that platen movement for upsetting can be initiated at any desired voltage phase of AC power source. The voltage phase of AC power source at the instant of platen movement for upsetting, named "upsetting point", showed significant influence on weld interface quality. The quality was best at the phase round 90 degree and worst at round 0 (or 180) degree. Good relasionship was observed between the phase and the quality. The influence of upsetting point control on weld interface quality was proved to be greater than that of duration of upset current by conventional current density, i.e. less than 80 A per square millimeter.

Oxidation of 1-benzyladenine (12) with m-chloroperoxybenzoic acid in MeOH or in MeOH-0.5 M phosphate buffer (pH 6.6) has been found to afford 1-benzyladenine 7-oxide (13) as the main product. Nonreductive debenzylation of 13 gave adenine 7-oxide (14) in 63% yield. The structure of 13 was unequivocally established by an X-ray crystallographic analysis.

Four-step synthetic routes from 3-methyladenine (10) to 7-benzyl-N6, 3-dimethyladenine (1b) and 7-benzyl-1, 2-dihydro-1, 3-dimethyladenine (2b), selected as models for the marine sponge alkaloids agelasimine-A (1a) and agelasimine-B (2a), respectively, have been established. The key steps involved are regioselective methylations of 7-benzyl-3-methyladenine (8) and 7-benzyl-1, 2-dihydro-3-methyladenine (11). The reaction of 1b with acetic anhydride in pyridine was found to give the monocyclic imidazole derivative 29b. A similar acetylation of 2b yielded the N6-acetyl derivative 20b. When treated with boiling H2O, 20b afforded 7-benzyl-2, 3-dimethylhypoxanthine (21b) and a compound inferred to be the dihydrohypoxanthine derivative 30. Probable pathways to 29b from 1b and to 21b and 30 from 20b are proposed.

Generating large-scale 3-D air turbulences similar to real situations in spatial characteristics defies the conventional wind tunnel test procedure but is requisite for evaluating the effect of turbulence of natural wind in engineering bridges and other large structures of optimum design matching the level of aerodynamic stability required.The authors added functional refinement to the 2-D blade rows and damper in the wind tunnel flow active system and also devised adjustable floor spires and blocks as another active flow control alternative. The prospect is good that selective use of these active flow control methods can successfully reproduce the large-scale 3-D air turbulences.

In an attempt to synthesize 2'-deoxy-7-methyladenosine (5b), 2'-deoxy-N6-methoxyadenosine (13b) was treated with MeI in AcNMe2 at 0°C for 7h to give the 2'-deoxy-N6-methoxy-7-methyladenosine salt (14b), which was unstable and easily underwent glycosidic hydrolysis in H2O at 16-18°C to form N6-methoxy-7-methyladenine (15). On account of such instability, hydrogenolysis of 14b in H2O using hydrogen and Raney Ni catalyst failed to afford the desired nucleoside (5b). 2'-Deoxy-N6-methyladenosine (2b), 2'-deoxy-1-methyladenosine (3b), and 14b were found to undergo glycosdic hydrolysis in 0.1 N aqueous HCl at 25°C at rates of 7.92×10-3 min-1 (half-life 87.5 min), 5.02×10-3 min-1 (half-life 138 min), and 2.31×10-2 min-1 (half-life 30.0 min), respectively, while the rate in the case of 5b was roughly estimated to be ca. 2 min-1 (half-life 0.35 min).

Diazotization of 5-amino-N'-methoxy-1-methylimidazole-4-carboxamidine (4a) with NaNO 2 in 1N aqueous HCI was found to give the 1-methoxy-2-azaadenine derivative 8a HI, which produced 5-azido-1-methylimidazole-4-carbonitrile (5a) on treatment with aqueous Na 2 CO 3 . The ribosyl analogue 5b, obtained from the riboside 4b by similar diazotization, was utilized for the synthesis of 5-azido-1-β-D-ribofuranosylimidazole-4-carboxamide (9b), a novel AICA riboside analogue. On heating in HCONMe 2 at 70°C for 10 min, 8a.HI yielded the 1-N-oxide 7a. Several reactions to transform the functional groups in 5a were also investigated.

This paper describes wind tunnel tests of the aerostatic force acting on rooftiles. Pressure distribution acting on full-sized model of rooftiles was measured. The rooftileswere set up on the gable roof of 5.1m wide ×3.2m deep ×2.0m tall in the wind tunnel. The pressure acting on the underside of the tiles, which was found to be both positive and negative due to the wind direction and the location of the rooftile, was effected by 1) gap between rooftile and sheathing board at the eaves, and 2) gap between the neighboring rooftiles.The authors assumed some model of pressure spreading underside the rooftiles, and caliculated the wind speed at which the dynamic equilibrium of roof tiles was losed.Compared with the wind speed at which the rooftiles scatter4], the wind speed was found to be lower about 30 %, but the pattern was similar to scattering.

We have devised a modified seton technique that resects the external fistula tract while preserving the anal sphincter muscle. This study assessed the technique when used for the management of complex anal fistulas.Between January 2006 and December 2007, 239 patients (208 males and 31 females, median age: 41 years) underwent surgery for complex anal fistulas using the technique. Of the 239 patients, 198 patients had trans-sphincteric fistula and 41 patients had supra-sphincteric fistula.The durations of the surgeries were 17 min (47, 13) [median (range, interquartile range)] for trans-sphincteric fistulas and 38 (44, 16) for supra-sphincteric fistulas. The durations of the surgeries were significantly (P 0.05) longer for supra-sphincteric fistula than trans-sphincteric fistula. The hospital stays were 4 (13, 2) days and 5 (14, 3) days, respectively, for trans- and supra-sphincteric fistulas. The durations of seton placement until the spontaneous dropping of the seton were 42 (121, 48) and 141 (171, 55) days respectively. The recurrence rate was 0 % in patients with trans-sphincteric fistulas and 4.9 % (2 of 41) in patients with supra-sphincteric fistulas (P 0.01). Serious incontinence was not observed.The technique provided favorable results for the treatment of complex anal fistulas and could be safely applied while preserving the sphincter function and conserving fecal continence.

PCNA (proliferating cell nuclear antigen) is a 36 KD polypeptide that is maximally expressed in late G1 and S phases of the cell cycle, and correlates with DNA synthesis. Although the rates of proliferating tumor cells have been reported to be a marker for the malignant potential of several tumors, the clinical significance of proliferative activity in oral malignancies has not yet been fully investigated. This article presents the results of an immunohistological analysis of 22 squamous cell carcinomas of the tongue using anti-PCNA monoclonal antibody. The rate of PCNA positive cells was significantly related to clinical stage (p

Electrode life tests were conducted in resistance spot welding of organic composite coated steel sheets. The electrode lives obtained were almost equivalent to those of ordinal coated steels despite the fact that electrodes during the tests rapidly wore out. The long electrode lives can be attributed to a high contact resistance between the material coated with an organic film and an electrode. That is to say, although the high contact resistance leads to the rapid wear of electrodes caused by a frequent surface flash, this in turn effectively restricts a current path into a specific contact area between the material surface and the electrode and maintains a high current density sufficient to form a nugget even when the electrode wears out.

Treatment of 9-ethy-1-(2-hydroxythyl)adenide hydrobromide (1a) in boiling N, N-dimethylformamide (DMF) with an excess of thiourea for 7 h or with an excess of ammonium thiocyanate for 3 h provided 3-ethyl-7, 8-dihydro-3H-imidazo[2, 1-i]purinium thiocyanate (8) in 51% or 58% yield, respectively. On treatment with an excess of triphenyl phosphite in boiling DMF for 20 min, 1 a underwent a similar cyclization to from the same tricycle, which was isolated in 81% yield (from 1 a)in the form of the perchlorate salt (12). A similar treatment of 1 a with triethyl phosphite furnished the 9-ethyl analogue (15) in 83% yield. Conversion of 12 into the free base and oxidation of latter with active MnO2 in boiling CH2Cl2 for 16 h gave 3-ethyl 3-ethyl-3H-imidazo[2, 1-i]purine (13) (66% overall yield from 12), which was identical with a sample synthesized from 9-ethyladenine (9) and chloroacetaldehyde according to the general N6, 1-etheno bridgeing procedure. On treatment with methanolic ammonia at room temperature, the tricycle 15 afforded 9-ethyl-N6-[2-(ethylamino)ethyl]adenine hydrobromide (26) in 79% yield. Mechanisms are proposed for the above intramolecular cyclizations of 1 a caused by the S- and P-atom nucleophiles.