bluuebunny/crossref_metadata_2025 huggingface dataset:
Imaging Approaches in Dementia: A Retrospective Cohort Study of Cross-sectional Imaging in the Indian Population
Authors: Sanzgiri Sanjana , Verma Mitusha , Thakrar Ritvik , Bhurrji Prishaa , Patkar Deepak
Published: February 2024

Introduction: Dementia is a broad medical term that describes the progressive cognitive decline of brain function due to disease or impairment, resulting in interference with daily activities. Magnetic Resonance Imaging (MRI) is commonly used for the clinical diagnosis of dementia by identifying cerebral atrophy and structural alterations. Furthermore, Magnetic Resonance Spectroscopy (MRS) can detect biochemical abnormalities in dementia patients, which may be beneficial for early diagnosis and treatment. Aim: To provide a comprehensive protocol and a guidance tool for radiologists to effectively diagnose dementia and its subtypes {Alzheimer’s Disease (AD), frontotemporal lobe dementia, etc.} based on radiological findings coupled with volumetry, spectroscopy, and Arterial Spin Labelling (ASL) findings. Materials and Methods: A retrospective observational study was conducted in the Department of Radiology, Nanavati Max Superspeciality Hospital, Mumbai, Maharashtra, India, between June 2022 and June 2023. A total of 125 patients were analysed to observe the correlation between whole brain volume, Intracranial Volume (ICV) of different cortical regions, hippocampal atrophy, and MRS findings. Descriptive statistics were used, and results were expressed as means and standard deviations for continuous variables, and as frequencies and percentages for categorical variables. Results: Out of 125 patients, 71 (56.8%) were males, and 54 (43.2%) were females, with ages ranging from 41 to 96 years. The majority presented with Mild Cognitive Impairment (MCI) 36 patients (28.8%) and Vascular Dementia (VaD) (18 patients - 14.4%). Some clinical features and imaging findings overlapped, resulting in some cases being a combination of different types of dementia. MRI, MRS, and Medial Temporal Atrophy (MTA) played a crucial role in allowing clinicians to perform a differential diagnosis. Conclusion: The use of MR volumetry and spectroscopy aids in classifying the type of dementia, which, in turn, gives treating clinicians a better perspective for further treatment and its outcomes.
H-shaped Talon Cusp in the Anterior Maxilla: A Diagnostic Dilemma
Authors: Alanazi, Nawadir Hamoud , Yadiki Josnavinutha
Published: February 2024

Dental anomalies are clinically evident abnormalities that cause a variety of dental problems. Depending on the tooth location, dens evaginatus indicates a posterior tooth abnormality, while talon cusp explains an anterior tooth anomaly. Identifying the problem and initiating treatment requires careful observation and proper investigations. Here, the authors present the case of a nine-yearold female child who had an H-shaped talon cusp or barrel-shaped bilateral maxillary lateral incisors in the form of premolars. The report includes clinical and radiographic interpretation. Associated problems and various treatment options are also explained. Although dental anomalies affecting the teeth are relatively common, the presentation of barrel-shaped or premolar-shaped bilateral maxillary lateral incisors is uncommon. Knowledge about the prevalence and distribution of such anomalies would aid various dental experts in early identification and recognition of dental malformations, as well as in complete treatment planning.
Enhancing Groundnut Productivity in Anantapur District, Andhra Pradesh: Identifying Constraints and Developing Adaptation Strategies
Authors: Mallikarjun M. , Harini M , Naik K Balaji , Sireesha E , Yugandhar V , Kumari C Radha
Published: February 2024

India is a world leader in groundnut farming. A purposive and random sampling technique was used for the study and conducted in KVK operated mandals of Anantapur and Satya Sai district. Ten mandals of KVK operational area were selected purposively where Cluster Front-Line Demonstrations were conducted and from each mandal 2 villages were selected purposively by KVK. Eight farmers from each village were selected randomly, thus making a total of 160 respondents for this study. An ex-post facto research design was used and the data were collected by interview method and enquired about the constraints faced by them for low groundnut productivity and queried suggestions to overcome the constraints faced by them. From the study, it was revealed that major constraints of the farmers faced were uncertainty in rainfall during crop growth period (96.25) followed by lack of irrigation facility (92.5 %), shortage of labour during critical stages (88.75%), low production due to pest and disease infestation (87.5%) and non-availability of appropriate market price (86.25) as reported by the farmers. Among the suggestions offered by farmers it was the supply of inputs at subsidized rate (76.25 %) ranked first followed by remunerative price should be made available to the groundnut farmers during drought years (75.0%) ranked second and irrigation facilities should be made available (72.5%) ranked third.
Soil Restoration Strategies for Sustaining Soil Productivity: A Review
Authors: Rathi Abhinav , Kumar Pardeep , Nangla Sumit , Sharma Shubham , Sharma Shalini
Published: February 2024

Soil degradation, characterised by a deterioration in quality and a drop in ecosystem products and services, is a key impediment to obtaining the necessary increase in agricultural productivity. Soil is a living and dynamic organism that degrades when standard agricultural practices are used. Healthy soil is a crucial pillar of sustainability because it provides various ecosystem services in addition to controlling microbial activity, nutrient recovery, and decomposition. In human time spans, soil is a non-renewable resource that is vulnerable to deterioration due to complex interactions between processes, variables, and causes occurring at a variety of geographical and temporal dimensions. Accelerated erosion, depletion of the soil organic carbon (SOC) pool and biodiversity loss, loss of soil fertility and elemental imbalance, acidification and salinization are among the key soil degradation processes. The strategy aims to minimize soil erosion, boost SOC and N budgets, boost soil biota activity and species diversity (macro, meso, and micro), and improve structural stability and pore geometry. Improving soil quality (i.e., expanding the SOC pool, improving soil structure, and boosting soil fertility) can lower the hazards of soil degradation (physical, chemical, biological, and ecological) while also benefiting the environment.
The Role of Cloud Computing in Personalized Medicine: A Systematic Review
Authors: Esho Temiwande , Ayeni Oluwafunto , Lasisi Oluwafunsho , Peter Olorunmaiye
Published: February 2024

This review critically examines the role of cloud computing in personalized medicine, employing a systematic literature analysis methodology. The study involved a comprehensive search and evaluation of scholarly articles from academic databases and journals, focusing on publications within the last decade. Key terms such as "cloud computing", "personalized medicine", "genomic data management", and "patient-centric healthcare technology" guided the literature search. The study illuminates the significant role of cloud computing in revolutionizing personalized medicine. It highlights the importance of cloud computing for managing large-scale genetic data and individualized patient care, as well as its role in enhancing patient-centric care through innovations like cloud-fog diagnostics. Challenges in data security, privacy, and ethical considerations are acknowledged, emphasizing the need for robust governance and compliance. The future of cloud computing in personalized medicine is poised for growth, with immense opportunities for innovation, yet accompanied by challenges in data management and healthcare equity. The ongoing evolution of cloud computing in healthcare promises substantial advancements, albeit with a need for careful consideration of its complexities to fully realize its potential.
Effect of Different Salinity Levels on Morphological and Yield-Related Traits of Tomato (Solanum lycopersicum L.)
Authors: Swati  , Vaishali  , Yadav M. K.  , Kumar P.  , Gangwar L. K.  , Sharma A. K.
Published: February 2024

Salinity stress arises from the accumulation of elevated salt levels in the soil, leading to the hindrance of plant growth and eventual crop loss. Compounds that induce stress tolerance exhibit a remarkable capacity to enhance growth and mitigate the impacts of salinity stress, all while maintaining a positive environmental impact by regulating plant activities. to investigate how varying levels of salinity in the irrigation water impact the morphological characteristics and yield of tomato plants. The experiment employed a complete randomized design with one plant per pot and three replicates per treatment, spanning from October 2021 to April 2022 and October 2022 to April 2023 at SVPUAT, Meerut. The objective was to investigate the impact of four NaCl levels (0, 50, 100, and 150 mM) on the Morphological traits of ten tomato cultivars (Arka Rakshak, Punjab Ratta, H-88-78-5, VRT-16-1, Pusa Ruby, Pant T-3, Arka Samrat, Kashi Aman, Kashi Anupam, Pusa Rohini) during the mature stage. Various genotypes displayed distinct reactions concerning plant growth, with a focus on factors such as plant height, the quantity of branches per plant, the number of flower trusses per plant, and the number of flowers per truss being examined. Parameters such as average fruit weight, fruit diameter, fruit length, and TSS were also measured. The findings revealed that increasing NaCl salinity adversely affected the morphological properties of all examined tomato plants compared to the control group (tap water). Salinity was found to decrease morpho and yield related parameters, except for TSS in tomato fruit. Nevertheless, there was a variation in the response to salt stress among the studied varieties. "Pusa Ruby" and "Pusa Rohini" demonstrated greater performance and stability under salinity stress, followed by Arka Rakshak and Kashi Aman, while Punjab Ratta, followed by Pant T-3, inferior performance under salinity. Water salinity significantly impacts the growth and production of crops, and the insights from this study can aid in the selection of better varieties in saline-affected areas. However, it is essential to further evaluate the potential of these genotypes under saline conditions and assess the variability in various biochemical parameters.
Potential Pterostilbene and Anti Inflammatory Effect on Rheumatoid Arthritis Therapy in Rattus norvegicus Rat
Authors: Hosni Andressa Panegalli , Cordeiro Maria Elvira Ribeiro , Luz Jaine Paula da , Bini Ana Carolina Dorigoni , Kerppers Ivo Ilvan , Kerppers Flávio Klinpovous , Biscaia Isabela Fanelli Barreto , Bernardi Larissa Sakis , Oliveira Paulo Renato de
Published: February 2024

Introduction: Rheumatoid arthritis (RA) is one of the most prevalent chronic inflammatory diseases, which primarily involves the joints and may also include extra-articular manifestations, such as nodules, pulmonary involvement, vasculitis, and systemic comorbidities. Pterostilbene (PTE) is responsible for the process of angiogenesis and contributes with its anti-inflammatory properties to the rheumatoid arthritis process.

Objective: To verify whether oral Pterostilbene solution use has an effect on the acute phase of the inflammatory process in the treatment of rheumatoid arthritis.

 Methodology: This experimental study was composed of 45 Rattus Norvegicus rats, Wistar strain, divided into three groups corresponding to the Control Group (CG) with no lesion and no treatment; the SHAM Group (SHAM) with lesion but no treatment, and the Pterostilbene Group (PG) with lesion and treatment. The results were evaluated by histology and flow cytometry.

Results: The lesions were characterized by a diffuse acute inflammatory process with mild to moderate intensity. It was observed that increasing proliferative activity of fibroblasts and angiogenesis occurred, besides the modulation of inflammatory cytokines, which corroborated the histological findings.

Conclusion: It can be concluded that pterostilbene, due to its anti-inflammatory activities, can control inflammation so that there are no exacerbated symptoms and lesions, in addition to stimulating structural restoration by increasing fibroblast production and angiogenesis.
Poly‐[N,N‐(1,4‐divinylbenzene‐β,β′‐diyl)‐4,4′‐bipyridinium dibromide], a novel conducting viologen polymer
Authors: Merz Andreas , Reitmeier Stefan
Published: December 2004

The title compound (see Figure) is a new, easily accessible π‐conjugated viologen polymer. Properties of particular interest are its conductivity of 1 ′ 10−3 S cm−1 and electroactivity in the potential region from −0.1 to −0.6 V vs. Ag/AgCl.

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Probing changes in the structure and performance of a lithium nickel oxide catalyst by in situ X‐ray diffraction during the high temperature oxidative coupling of methane
Authors: Pickering Ingrid J. , Maddox Peter J. , Thomas John M.
Published: December 2004

The advantages of in situ X‐ray diffraction in clarifying the onset and nature of the distinct kinds of catalytic action exhibited by a lithium nickel oxide for the oxidation of methane at elevated temperatures are demonstrated. Active solids may possess structural features quite unlike those deduced from measurements conducted at ambient temperatures and pressures emphasizing the need for the development of in situ methods.
Polymer benzo[15] crown‐5 complexes as sensor materials for solvent vapors—aromatic halogenated hydrocarbons and polar solvents
Authors: Dickert Franz L. , Zeltner Doris
Published: December 2004

For the first time thin layers of polymer‐metal complexes with crown ether ligands (see figure) have been applied as sensor materials for the detection of solvent vapors. The hydrophobic properties of these films enable the detection through conductivity measurements of even halogenated and aromatic hydrocarbons.

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Martensitic transformations in bochum
Authors: Jost Norbert
Published: December 2004

Martensitic transformations are first order structural phase transformations which occur in a range of crystalline solids. A recent meeting in this field in Bochum, FRG, is reviewed by N. Jost while W. Kaysser reports that Las Vegas was the scene of a conference on particle technology.
Composites and particle technology in las vegas
Authors: Kaysser Wolfgang A.
Published: December 2004

Martensitic transformations are first order structural phase transformations which occur in a range of crystalline solids. A recent meeting in this field in Bochum, FRG, is reviewed by N. Jost while W. Kaysser reports that Las Vegas was the scene of a conference on particle technology.
The European Materials Research Society (E‐MRS)
Authors: Krimmel Eberhard F.
Published: December 2004

Since its birth in 1986, the European MRS has been going from strength to strength. Regular interdisciplinary meetings are held and educational programs as well as European Research Networks are supported, these activities making up the basis of a thriving society. In this month's Editorial Essay a former secretary of the E‐MRS traces the society's early development, assesses its current position and looks forward to its undoubtedly bright future.
Structure of anodic oxide coatings on aluminum
Authors: Kniep Rüdiger , Lamparter Peter , Steeb Siegfried
Published: December 2004

The structure of the remarkably uniform array of pores in surface coatings on aluminum has been investigated using X‐ray and neutron diffraction techniques. The almost hexagonally shaped cells make the films of interest for application in the field of synthetic membranes and as supports for active materials.
Tailoring Semiconductor Crystal to atomic dimensions
Authors: Joyce Bruce A.
Published: December 2004

This article provides an introduction to the growth by molecular beam epitaxy (MBE) of semiconductor structures which have dimensions of the same order as interatomic distances in solids. The basic process technology is first described, followed by a brief account of surface reaction mechanisms involved in the growth of GaAs from an atomic beam of Ga and molecular beams of As4 and As2.

From the study of growth dynamics using electron diffraction techniques it is shown how reduced dimensionality structures can be grown and some indication is given of the effects of quantum confinement on material properties. Finally, some recent modifications of MBE based on flux interruption are described.
Gauge theory – a new outlook on solid state dynamics
Authors: Clough Stanley
Published: December 2004

The hitherto mysterious relationship between the quantum and classical descriptions of solid state dynamic processes has been reexamined recently. It has been found that quantum theory has been missing important features such as symmetry breaking and Berry's phase, the incorporation of which does away with the rather fuzzy Copenhagen interpretation and rationalizes solid state behavior.
Advanced dielectrics: Bulk ceramics and thin films
Authors: Hennings Detlev , Klee Mareike , Waser Rainer
Published: December 2004

Review: Ceramic multilayer capacitors used in surface‐mount electronics have decreased in size by a factor of four over the last five years while their capacitance per unit volume has increased by the same factor. The preparation and processing procedures applied to ultrafine dielectric ceramic powders used in the capacitors (see Figure), which have resulted in these improvements in size and performance characteristics are described.

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Immobilization of enzymes on langmuir–blodgett films via a membrane‐bound receptor. possible. applications for amperometric biosensors
Authors: Schuhmann Wolfgang , Heyn Sven‐Peter , Gaub Hermann E.
Published: December 2004

Communication: An amperometric biosensor for glucose, based on an immunological recognition process between an antigen binding fragment (Fab, see Figure), immobilized in a planar bilayer lipid membrane, and glucose oxidase. The enzyme‐catalyzed formation of H2O2 in the presense of glucose can be detected amperometrically by means of an electrode. The principle of this sensor is also applicable for sensing a wide range of other substrates.

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Co/Pt multilayers for magneto‐optical recording
Authors: Zeper W. Bas , van Kesteren Hans W. , Carcia Peter F.
Published: December 2004

Research News: Magnetic multilayers have emerged as an alternative to amorphous rare‐earth transition‐metal alloys for application in magneto‐optical recording media. Their success has been due to their intrinsic resistance to oxidation and corrosion, large Kerr rotation at shorter wavelengths, ease of preparation, and thermal stability. The Figure shows thermo‐magnetically written domains on a Co/Pt disc, written at the given fields.

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Organic materials for frequency doubling
Authors: Staring E. G. J. , Rikken G. L. J. A. , Seppen C. J. E. , Nijhuis S. , Venhuizen A. H. J.
Published: December 2004

Research News: Organic nonlinear optical (NLO) materials offer and alternative approach to a blue laser to the inorganic materials described by Ouwerkerk (this issue). The criteria for efficient organic NLO materials which are transparent at both 820 nm, the emmission frequency of GaAs/AlGaAs diode lasers, and 410 nm, the frequency of the frequency‐doubled blue light are discussed with special reference to compounds studied at Philips (e.g. see Figure).

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Seasonal control of arsenic speciation in an estuarine ecosystem
Authors: Howard A G , Apte S C
Published: December 2004

Arsenic speciation in the Itchen estuary and Southampton Water (UK) has been shown to vary seasonally, with detectable (>0.02μg As dm−3) dissolved arsenic(III) and methylated arsenic only being present from May to early October. This corresponds to the time period during which water temperatures exceed 12°C. For the remainder of the year, inorganic arsenic(V) was the only detectable species. At its peak, ca 30% of the dissolved arsenic was present as methylated forms with dimethylarsenic (DMAs) being the predominant bioarsenical. Significant quantities of monomethyl‐arsenic (MMAs) and inorganic arsenic(III) were also present, however.

The concentrations of the bioarsenical species varied with position in the estuary and generally increased with salinity. Measurements made during the period of peak algal activity implicated the highsalinity area of the estuary as the most probable region in which the methylated arsenicals are generated. At some sites, a distinct lag was observed between the appearance of dimethylarsenic and the detection of arsenic(III)and monomethylarsenic. Chlorophyll a concentration proved to be a poor predictor of the appearance of reduced and methylated arsenic in the water column. Possible sources of dissolved methylated arsenic are discussed.
The uptake of arsenicals by Candida humicola
Authors: Cullen William R , McBride Barry C , Pickett A Wendy
Published: December 2004

The uptake of arsenate by Candida humicola requires an active transport system and may operate through low‐ and high‐affinity sites. Arsenite, methylarsonate and dimethylarsinate are deduced to enter the cell by slow passive diffusion.
Arsenic in the natural environment. Part II: Arsenic concentrations in thermal waters from Japan
Authors: Tanaka Takeshi
Published: December 2004

Arsenic is ubiquitous in the atmosphere, hydrosphere, pedosphere, lithosphere, and biosphere of the earth. Hot springs in Japan have arsenic concentrations as high as 25 mg kg−1, Generally, the hotter the water the higher are the arsenic concentrations. On average, acidic waters have higher arsenic concentrations than alkaline waters. The arsenic concentrations are positively correlated with the antimony and the lead concentrations. The daily discharge of arsenic from a geothermal well may reach a total of 220 kg. The arsenic concentrations, the temperatures, and the pH values for some Japanese thermal waters are tabulated.
Growth characteristics and arsenic metabolism of two species of arsenic‐tolerant bacteria
Authors: Maeda Shigeru , Ohki Akira , Miyahara Kuniaki , Takeshita Toshio , Higashi Shiro
Published: December 2004

Two arsenic‐tolerant bacterial species were isolated from a contaminated culture of the alga Chlorella sp. One of the bacterial species was identified as Pseudomonas putida; both were aerobic heterotrophs. The bacteria grew well in a peptone medium of neutral pH at room temperature and reached the stationary phase in approximately four days. Growth was not impaired by arsenic concentration as high as 1000 mg dm−3 As in the form of arsenate, but decreased drastically at higher concentrations. P. putida grown in a peptone medium with 10 mg dm−3 As as arsenate, reached a maximal arsenic concentration of 67 mg kg−1 (dry mass) after 48 h of growth in the late log phase. Most of the arsenic in the cells was inorganic and 3% of the arsenic was in the trimethylated form. During the stationary phase the bacteria excreted arsenic largely in the inorganic, but also in the inorganic, but also in the mono‐, di‐, and trimethylated, forms.
Accumulation of arsenic and selenium by Dunaliella sp.
Authors: Yamaoka Yukiho , Takimura Osamu , Fuse Hiroyuki , Kamimura Kazuo
Published: December 2004

The unicellular marine alga, Dunaliella sp., was grown in seawater containing selenium and arsenic. Dunaliella sp. readily took up selenite from the medium over a broad range of concentrations (10−10–10−5mol dm−3). In comparison, uptake from selenate was generally minimal. Selenite was detectable in cells within 24 h and concentrations increased gradually with time. Also iron and zinc concentrations in Dunaliella sp. cells were largely affected by addition of arsenic and gallium. Arsenic concentrations in cultures were largely correlated to the accumulation of arsenic by Dunaliella sp., but did not affect the accumulation of selenium by Dunaliella sp. This implied that the accumulation process of selenium was different from that of arsenic.
Effect of metal ions on accumulation of arsenic in marine green algae, Dunaliella sp.
Authors: Takimura Osamu , Fuse Hiroyuki , Yamaoka Yukiho
Published: December 2004

To investigate the effect of metal ions such as cobalt(II), copper(II), molybdenum(VI) and manganese(II) on the accumulation of arsenic in Dunaliella sp., the amount of arsenic accumulated in these algae was determined under coexistence of arsenic and the other metals by the hydridegeneration atomic absorption spectrometry method. Survival of Dunaliella sp. was inhibited by the addition of copper and cobalt in a solution containing arsenic. Copper and cobalt in the medium also inhibited the accumulation of arsenic in Dunaliella sp., and the amount of arsenic in the algae decreased with increase in the concentration of copper and cobalt. On the other hand, the amount of arsenic accumulated in Dunaliella sp. was found to be unaffected by manganese and molybdenum in the solution.
Effects of phosphate on arsenate inhibition in a marine cyanobacterium, Phormidium sp.
Authors: Takahashi Akira , Kawakami Hidekazu , Bada Akira , Okonogi Yasutaka , Matsuto Shigeki
Published: December 2004

The effect of arsenate on cells of a marine cyanobacterium, Phormidium sp. preliminarily starved for phosphate for a week was studied. Cells were harvested and cultured in artificial seawater containing various concentrations of arsenate and phosphate. Arsenate at concentrations above 30 mg As dm−3 inhibited biosynthesis in the cells and consequently, growth when incubated without phosphate in the medium. On the contrary, phosphate at 50 μmol dm−3 was sufficient for apparently complete cancellation of the inhibitory effects of arsenate at concentrations up to 150mg As dm−3. Study of the carbohydrate metabolism revealed an intense inhibition by arsenate on turnover of carbohydrate to other cell components in the phosphae‐depleted cells. This resulted in a color change of the cells from blue–green to yellowish. The synthesis of carbohydrate itself was also inhibited by arsenate. Arsenate incorporation into cells was clearly inhibited by phosphate in the medium, suggesting that arsenate competes with phosphate for entry into cells. In addition, arsenate incorporated in cells could not inhibit the incorporation of phosphate and subsequent growth of cells on phosphate. These observations indicate that arsenate can act as a poisonous substitute for phosphate in the cells but, once incorporated into the phosphate‐replete cells, it no longer has an inhibitory effect. The inhibitory effects of arsenate seem to be mainly related to ATP synthesis in the photosynthetic system.
The exploitation of new synthetic reactions by means of rare earth metals
Authors: Takaki Ken , Fujiwara Yuzo
Published: December 2004

This review deals with lanthanoid mediated organic reactions investigated by the authors. The scope of the lanthanoid‐mediated reactions are discussed under the following topics:

Reactions of Yb metal umpoled diaryl ketones with electrophiles;

Reactions of Yb metal with imines;

Reactions of Yb metal with CC multiple bonds;

Reactions of Sm metal with nitroarenes;

Reactions of Yb metal with α,β‐unsaturated carbonyl compounds;

Reactions of a PhYbI σ‐complex;

Reactions of LnCl3 as Friedel‐Crafts catalyst.
Structure–activity relationships for organotin compounds on the red killifish Oryzias latipes
Authors: Nagase Hisamitsu , Hamasaki Tetsuo , Sato Takahiko , Kito Hideaki , Yoshiokat Yoshitada , Ose Youki
Published: December 2004

The LC50 values of a series of 29 organotin compounds were determined for the red killifish (Oryzias latipes) according to an OECD test guideline. Their toxicities varied from 10−1 to 10−5 mmol dm−3 in five orders of magnitude. In this paper a quantitative structure‐activity relationship (QSAR) study of these organotin compounds was carried out using physicochemical and topological parameters as independent variables. These parameters were found not to be good descriptors for estimating the LC50 values. However, when the term index Value (IV), which is created as a new parameter and is defined by the number of phenyl or alkyl groups attached to the tin atom, was used, excellent regression equations to predict the toxicities of organotin compounds were obtained and a multiparametric relationship including IV, Information Index (IWD and Mean Information Index (IWD)) showed the best correlation.
X‐Ray photoelectron spectroscopy and electrical conductivity studies of metallophthalocyanine sheet polymers
Authors: Nalwa Hari Singh
Published: December 2004

The X‐ray photoelectron spectroscopy (XPS) technique has been used to characterize metallophthalocyanine sheet polymers having peripheral carboxyl groups. A comparative analysis of the XPS and electrical conductivity data of metal‐free, and nickel‐ and copper‐containing, phthalocyanine sheet polymers has been described. Metallophthalocyanine sheet polymers exhibited a maximum conductivity of about 1 S cm−1 on pyrolysis.
Organometallic chemistry related to applications for microelectronics in Japan
Authors: Sato Hiroyasu
Published: December 2004

This is meant to be a brief overview of the developments of research activities in Japan on organometallic compounds related to their use in electronic and optoelectronic devices.

The importance of organometallic compounds in the deposition of metal and semiconductor films for the fabrication of many electronic and opto‐electronic devices cannot be exaggerated. Their scope has now extended to thin‐film electronic ceramics and high‐temperature oxide superconductors. A variety of organometallic compounds have been used as source materials in many types of processing procedures, such as metal–organic chemical vapor deposition (MOCVD), metalorganic vapor‐phase epitaxy (MOVPE), metal–organic molecular‐beam epitaxy (MOMBE), etc. Deposited materials include silicon, Group III–V and II–VI compound semiconductors, metals, superconducting oxides and other inorganic materials.

Organometallic compounds are utilized as such in many electronic and optoelectronic devices; examples are conducting and semiconducting materials, photovoltaic, photochromic, electrochromic and nonlinear optical materials.

This review consists of two parts: (I) research related to the fabrication of semiconductor, metal and inorganic materials; and (II) research related to the direct use of organometallic materials and basic fundamental research.
XPS study on early stages of heat deterioratin of silicon‐containing aromatic polymide film
Authors: Sugitani H , Kikuchi T , Sugimoto Y , Saitou T
Published: December 2004

Early stages of heat deterioration of some siliconcontaining aromatic polyimide thin films with disiloxane groups (I) in their main chains were studied with XPS. It was found that the thermal decomposition of silicon‐containing aromatic polyimides takes place at lower temperatures than those not modified with silicon. The low thermal stabilities observed are explained by the easier decomposition of silicon–carbon bonds (e.g. silicon–methylene, silicon–aryl) than other bonds (e.g. carbon–carbon, carbon–oxygen). Particularly, silicon–methylene bonds (II) readily undergo thermal oxidative decomposition and start to decompose at 350°C under aerobic conditions. This starting temperature of thermal decomposition is lower by 100°C than that of the corresponding polyimide not modified with silicon. In the case of polyimide incorporating silicon–aryl bonds (III) instead of silicon–methylene bonds, the decrease in the thermal decomposition temperature is as small as 50°C, and decomposition under aerobic conditions starts at 400°C.
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The epitaxial growth of AlGaAs using highly purified trimethylaluminum
Authors: Maeda T , Hata M , Isemura M , Yako T
Published: December 2004

Highly purified trimethylaluminum [(CH3)3Al] was prepared by reducing the contamination of volatile impurities such as organic silicon and dimethyl‐aluminum methoxide [(CH3)2AlOCH3]. The concentration of methoxy group in (CH3)3Al was found to decrease considerably when (CH3)2Al was distilled in the presence of aluminum trihalide. Among the halides, purification efficiency increased in the order I>Br>Cl.

High‐quality AlGaAs layer and AlGaAs/GaAs modulation doped structures were grown by organometallic vapor‐phase epiloxy (OMVPE) using the purified (CH3)3Al. Their electrical properties were discussed in relation to the volatile impurity in the source gas.
Synthesis of poly‐yne polymers containing transition metals, disilane, disiloxane and phosphine groups in the main chain
Authors: Kotani S , Shiina K , Sonogashira K
Published: December 2004

The synthesis and characterization of metal poly‐yne polymers containing disilane, disiloxane and phosphine groups in the main chain are described. The platinum and palladium poly‐yne polymers were synthesized by polycondensation reactions between a metal chloride and an α, ω‐bisethynyl complex in amines in the presence of cuprous iodide as a catalyst. The nickel poly‐yne polymers were synthesized by an alkynyl ligand exchange reaction between a nickel acetylide and an α, ω‐bisethynyl complex in diethylamine in the presence of cuprous iodide as a catalyst. The reaction of the platinum poly‐yne polymer, containing disiloxane groups in the main chain, with copper (I) salts afforded adducts of η‐2‐bonded σ‐acetylide polymer complexes. The reactions of the palladium poly‐yne polymer, containing phosphine groups in the main chain, with transition‐metal carbonyl complexes afforded polymer complexes which have phosphorus in the main chain‐transition‐metal bonds. A concentrated solution of the platinum poly‐yne polymer containing disiloxane groups in the main chain forms a lyotropic liquid crystal in dichloromethane or 1, 2‐dichloroethane.
Conversion of arsenobetaine to dimethylarsinic acid by arsenobetaine‐decomposing bacteria isolated from coastal sediment
Authors: Hanaoka Ken'Ichi , Tagawa Shoji , Kaise Toshikazu
Published: December 2004

Arsenobetain [(CH3)3As+CH2COO‐]‐containing growth media (1/5 ZoBell 2216E and solution of inorganic salts) were inoculated with two bacterial strains, which were isolated from a coastal sediment and identified as members of the Vibro‐Aeromonas group, and incubated under aerobic and anaerobic conditions. Arsenobetaine was converted to a metabolite only under aerobic conditions. This arsenic metabolite was identified as dimethylarsinic acid [(CH3)2AsOOH] by hydride generation/cold trap/GC MS/SIM analysis and high‐performance liquid‐chromatographic behaviour. The conversion pattern shown by these arsenobetaine‐decomposing bacteria (that is, arsenobetaine → dimethylarsinic acid) was fairly different from that shown by the addition of sediment itself as the source of arsenobetaine‐decomposing micro‐organisms (that is, arsenobetaine → trimethylarsine oxide → inorganic arsenic). This result suggests to us that various micro‐organisms, including the arsenobetaine‐decomposing bacteria isolated in this study, participate in the degradation of arsenobetaine in marine environments.
Structural effects on the antitumour activity of organotin compounds 2. Further diaryltin dichloride complexes with nitrogen‐donor ligands
Authors: Biddle Brian N , Gray J S
Published: December 2004

The synthesis and investigation of the anti‐tumour activity of a further series of six new diorganotin dichloride complexes Ar2SnCl2.L2, where Ar = 2‐thienyl, 2,4‐dimethoxyphenyl, 4‐methyoxyphenyl, 4‐methylphenyl or 4‐trifluoromethylphenyl and L2 = 2‐(2‐pyridyl)benzimidazole (PBI) or 2‐amino‐methylpyridine (AMP), is reported. One of these complexes was found to be active against P388 lymphocytic leukaemia in mice. The results obtained are in general agreement with previously published work. The activity of the diaryltin dichloride complexes is shown to be dependent on the electronic effect of the aromatic group. The use of PBI as a ligand, however, shows no advantage over other ligands used in the series investigated.
Synthesis, characterization and in vitro antitumor activity of dimethyl‐, diethyl, and di‐t‐butyl‐tin(IV) derivatives of substituted salicylic acids
Authors: Bouâlam Mohammed , Willem Rudolph , Biesemans Monique , Gielen Marcel
Published: December 2004

The synthesis of dimethyl‐, diethyl‐ and/or di‐t‐butyl‐tin(IV) derivatives of substituted salicylic acids of the type a, (X‐Y‐2‐OH‐C6H2COO)2SnR2 (X, Y  H, H; H, 5‐CH3; H, 5‐Cl; H, 5‐F; H, 3‐CH3O; H, 5‐CH3O; 3‐CH3, 6‐(CH3)2CH; 3,5‐[(CH3)2CH]2 and 4,5‐benzo) and b {[R2(X‐Y‐2‐OH‐C6H2COO)Sn]2O}2 (X, Y  H, 3‐CH3O; H, 5‐CH3O: 3‐CH3, 6‐(CH3)2CH; 3,5‐[(CH3)2CH]2 and 4,5‐benzo) is reported. Their characterization by 1H, 13C and 119Sn NMR, Mössbauer and mass spectrometry is described. The in vitro antitumor activity of selected derivatives against two human tumoral cell lines, MCF‐7 and WiDr, is presented.
Structural chemistry of organotin carboxylates XV. Diorganostannate esters of dicyclohexylammonium hydrogen oxalate. Synthesis, crystal structure and in vitro antitumour activity of bis(dicyclohexyl‐ammonium) bisoxalatodi‐n‐butylstannate and bis(dicyclohexylammonium) μ‐oxalatobis(aquadi‐n‐butyloxalatostannate)
Authors: Ng Seik Weng , Kumar Das V. G. , Gielen Marcel , Tiekink E. R. T.
Published: December 2004

Dicyclohexylamine, oxalic acid dihydrate and di‐n‐butyltin oxide were reacted in 2:2:1 or 2:3:2 stoichiometries in ethanol solution to yield, respectively bis(dicyclohexylammonium) bisoxalatodi‐n‐butylstannate (1) and bis(dicyclohexylammonium) μ‐oxalatobis(aquadi‐n‐butyloxalatostannate) (2); the hydrate was also obtained upon recrystallization of 1 from moist acetonitrile solution. The crystal structures of the two ammonium stannates have been determined at room temperature. In 1, the tin atom in the dianion exists in a skewtrapezoidal bipyramidal geometry with the basal plane being defined by two bidentate oxalate ligands; each ligand forms asymmetric SnO bonds [SnO 2.348(4), 2.110(4) Å and 2.112(4), 2.363(4) Å]. The apical sites are occupied by the two organo groups disposed over the weaker SnO bonds. In 2, the two tin centres of the dianion are connected via a tetradentate oxalate ligand situated about a centre of inversion and each tin atom exists in a pentagonal bipyramidal geometry. The pentagonal plane is defined by four oxygen atoms, two from the central ligand [SnO 2.282(4), 2.473(4)Å] and two from a ‘terminal’ oxalate ligand [SnO 2.239(4), 2.210(4)Å], and the fifth site is occupied by a water molecule of crystallization [SnO 2.422(4)Å]; the apical sites are filled by the n‐butyl groups. Both compounds feature extended hydrogen‐bonded networks involving the oxygen atoms of the dianion and the N‐bound hydrogen atoms. Crystals of 1 are monoclinic, space group P21/n, with cell dimensions a = 13.408(3), b = 22.461(4), c = 13.996(2)Å, β = 100.97(2)°; full‐matrix least‐squares refinement on 3305 reflections with I≥2.5σ(I) converged to R = 0.042 and Rw = 0.046. Crystals of 2 are monoclinic, space group P21/n, a = 13.729(3), b = 14.694(2), c = 14.889(2)Å, β = 104.83(2)º; refinement on 2093 reflections converged to R = 0.030 and Rw = 0.031. The two di‐n‐butylstannates were screened in vitro against the mammary MCF‐7 and WiDr colon carcinoma cell lines, and were found to be as active as cisplatin, a clinically used antineoplastic drug.
Wissenschaft aktuell
Authors: Mayr Herbert , Schultz Günter , Jaenicke Lothar
Published: December 2004

Mit George A. Olah hat die Königlich Schwedische Akademie der Wissenschaften erstmals und für manche überraschend einen Forscher für Arbeiten auf dem Gebiet organischer Reaktionsmechanismen und reaktiver Zwischenstufen mit dem Nobelpreis ausgezeichnet, eine Ehre, die selbst C. K. Ingold (1893 – 1970), dem Begründer dieser Arbeitsrichtung, versagt blieb. Der Nobelpreis für Medizin und Physiologie ging in diesem Jahr an die beiden US‐Amerikaner Alfred G. Gilman und Martin Rodbell für ihre Arbeiten über die G‐Proteine.
Transneuronal changes in the lateral geniculate nucleus of the squirrel monkey, Saimiri sciureus
Authors: Jacobs Gerald H.
Published: December 2004

Long‐term transneuronal changes have been investigated in the lateral geniculate nucleus of the squirrel monkey (Saimiri sciureus). Recent reports that the parvocellular portion of that nucleus is laminated in typical primate fashion are verified. Measurements of changes in cell size indicate that, (a) cells in the parvocellular layers show greater shrinkage than do cells in the magnocellular layers and, (b) there is little change in cell size for enucleation terms of one versus two years. Measurements are also presented which suggest that lateral geniculate cells retaining retinal input in the monocular squirrel monkey show an increase in cross‐sectional area so that enucleation may lead to both atrophic and hypertrophic changes.
Electron microscopical study on the development of the satellite cell sheath in spinal ganglia
Authors: Pannese Ennio
Published: December 2004

The spinal ganglia of the fowl have been studied from the third incubation day to the adult.

The neuroblasts are the first cells that differentiate in the ganglionic anlage. Satellite cells, probably arising from the undifferentiated elements scattered among the neuroblasts, become detectable during the fifth incubation day. They appear starshaped with attenuated cytoplasmic expansions intervening between adjacent neuroblasts. At this time the neuroblasts largely outnumber the satellite cells.

From the sixth incubation day connective tissue spaces, appearing as large intercellular gaps containing an amorphous material, become evident between satellite cells. During the second half of the incubation period each nerve cell is completely enveloped by a satellite cell sheath, which is in turn entirely surrounded by a connective tissue space. The satellite cells change in shape from star‐shaped to flat elements. By this time and even more so in adult life, satellite cells outnumber nerve cells.

The satellite cells increase progressively in number, up to the ninth incubation day mainly through differentiation of undifferentiated cells; but later on by mitotic reproduction of fully differentiated satellite cells.

The neuron‐satellite cell boundary becomes more and more complicated with time, thus enlarging in parallel with the increase in volume of the nerve cell. Adhering junctions may be observed along this boundary.

The significance of the ergastoplasm, centrioles and cilia of the satellite cells is briefly discussed. Numerous adhering and scarce occluding junctions, some of which are temporary, link satellite cells.
The general visceral efferent component of the eighth cranial nerve
Authors: Ross Muriel D.
Published: December 2004

Study of the brain stem, stato‐acoustic nerve, and inner ear of the mouse by a cholinesterase technique has disclosed that the acetylcholinesterase‐positive centrifugal fibers to the inner ear are part of a general visceral efferent system which supplies fibers to the facial, vestibular and cochlear nerves. This system largely corresponds in its central course to that of the bundle of fibers which has been called “olivocochlear”, but its cells of origin do not appear to lie in the superior olivary complex. Instead, the preganglionic cells of origin are chiefly organized into four nuclei: one medial to the genu of the facial nerve; one lateral to the genu; the superior salivatory nucleus; and a small nucleus lying within the borders of the lateral vestibular nucleus. The fibers to the inner ear synapse, perhaps completely, on postganglionic cells located along their peripheral courses. Additionally, orthosympathetic acetylcholinesterasepositive fibers are present in the cochlear nerve; they arrive via the anterior inferior cerebellar artery. Postganglionic fibers supply not only vascular walls and secretory epithelium in the inner ear but also (1) contact the somata of some acetylcholinesterase‐positive, bipolar cochlear neurons and (2) ramify among, or terminate upon distal, acetylcholinesterase‐positive processes of some sensory neurons at the foramina nervosa. These finding indicate that, on morphological grounds, autonomic nerve activity may influence auditory input at the periphery.
Some aspects of the interneuronal connections in cat's spinal gray matter
Authors: Matsushita Matsuo
Published: December 2004

The pathways of the neurites of various neurons and their interrelations through axon‐collaterals were investigated in the spinal cord of young kittens using silver impregation techniques. The cells of lamina II connect with other cells of laminae II and III through collaterals. The axons of lamina III cells enter the lateral cord and their collaterals connect with cells of laminae III–IV. The axons of lamina V cells enter the lateral cord and some of their collaterals terminate in the neighborhood and in lamina IX. The cells of lamina VI connect with cells of laminae II–VI. The posterior commissural cells give their collaterals to cells of the intermediate nucleus and of the posterior horn of the both sides. Intermediate‐axoned cells (Valverde, '61) were found in the intermediomedial nucleus and lamina VII. Interconnections of small neurons of each lamina (Rexed, '52, '54) and their physiological significance were discussed.
Multiple projection of the visual field to the medial portion of the dorsal lateral geniculate nucleus and the adjacent nuclei of the thalamus of the cat
Authors: Kinston W. J. , Vadas M. A. , Bishop P. O.
Published: December 2004

The organization in the cat of the projection of the visual field onto the medial part of the central half of dorsal lateral geniculate nucleus (LGNd), the medial interlaminar nucleus (MIN) and the posterior nucleus of the thalamus (PN) has been studied by systematically plotting the receptive fields of single units isolated in the nuclei by tungsten microelectrodes. Using a grid of verticals (azimuth) and horizontals (elevation), projection maps were prepared by locating the recording sites of the units in serial histological sections. We have plotted three separate but related topographical projections of the visual field, one in each nucleus. Particular attention was paid to the projection of the visual axis in the LGNd. With the possible exception of the upper periphery, the whole of the visual field is represented in the MIN, the topographical organization with respect to azimuths being the mirror‐image of that in the LGNd. There were very few binocularly activated units in the MIN and no evidence was found of a laminar segregation of crossed and uncrossed optic tract terminals. The topographical projection onto the PN resembled that in the MIN except that the upper visual field was even more restricted and the organization of azimuth values was again reversed such that the central visual field projected inferomedially and the peripheral field dorsolaterally. In all three nuclei a naso‐temporal overlap was found with receptive fields located across the midline in the ipsilateral hemifield for about 2° in the case of LGNd units and 6° or more in the case of the MIN and PN. Some observations are made on visually active units in the lateral posterior nucleus of the thalamus and the pulvinar, many responding binocularly.