bluuebunny/crossref_metadata_2025 huggingface dataset:
Nuclear Survivin Is a Powerful Novel Prognostic Marker in Gastroenteropancreatic Neuroendocrine Tumor Disease
Authors: Grabowski Patricia , Griβ Sonja , Arnold Christian N. , Hörsch Dieter , Göke Rüdiger , Arnold Rudolf , Heine Berhard , Stein Harald , Zeitz Martin , Scherübl Hans
Published: April 2005

Gastroenteropancreatic neuroendocrine tumors represent a heterogeneous tumor entity. The growth pattern ranges from very slowly to fast growing, aggressive types of tumors. Survivin, a member of the family of apoptosis inhibitors, is a bifunctional protein that suppresses apoptosis and regulates cell division. In this study we determined the prognostic value of survivin in this tumor entity. Tumor specimens from 104 patients (38 foregut, 53 midgut, 13 hindgut) were studied immunohistochemically for cytoplasmic and nuclear survivin expression as well as for ki-67 antigen expression. 5-year-follow-up was complete in 89 patients. 29 patients with localized, well-differentiated gastroenteropancreatic neuroendocrine tumors (WDET, WHO class 1) had been curatively treated by surgical or endoscopic tumor resection. 50 patients suffered from well-differentiated endocrine carcinomas (WDEC, WHO class 2), 10 patients were diagnosed with poorly differentiated neuroendocrine carcinomas (PDEC, WHO class 3). Survivin expression was correlated with survival for the 50 patients with metastatic WDEC disease. All 29 WDETs were negative for nuclear survivin, whereas all 10 PDECs stained positive for nuclear survivin. In the 50 patients with metastatic WDECs, 5/50 (10%) tumors were nuclear survivin positive. Those 5 patients had a statistically significant worse prognosis (survival of 41 vs. 103 months, p = 0.01). ki-67 was not a prognostic factor in this subgroup of patients. Nuclear survivin expression thus appears to be upregulated during progression of gastroenteropancreatic neuroendocrine tumors. The analysis of nuclear survivin expression identifies subgroups in metastatic disease (WHO class 2) with good (survivin–) or with less favorable prognosis (survivin+). We propose that the determination of nuclear survivin expression could be used to individualize therapeutic strategies in this tumor entity in the future.
Differential Regulation of Female Rat Olfactory Preference and Copulatory Pacing by the Lateral Septum and Medial Preoptic Area
Authors: Xiao Kai , Kondo Yasuhiko , Sakuma Yasuo
Published: April 2005

We examined the effect of bilateral radiofrequency lesions in the lateral septum (LS) or medial preoptic area (MPOA) on olfactory preference (time spent sniffing odors derived from either a stud or castrated male) and pacing behavior (paracopulatory behavior in a cage with a compartment inaccessible to males) in ovariectomized rats following different hormonal regimes. Sham-operated and LS-lesioned females, but not MPOA-lesioned females, preferred odors from the stud males to the castrated males. MPOA lesions significantly decreased total nose-poking time, compared to that of sham-operated females. When mounted by stud males, both LS- and MPOA-lesioned females showed significantly higher lordosis quotients than sham-operated females. On the other hand, LS-lesioned females spent a significantly longer time in the male compartment, and stayed with the males even after they were mounted. These results suggest that the LS and MPOA play different roles in the sociosexual activity in female rats, and that the two regions exert an inhibitory influence on lordosis.
17β-Estradiol Modulates hMT1 Melatonin Receptor Function
Authors: Masana Monica I. , Soares Jr. Jose M. , Dubocovich Margarita L.
Published: April 2005

Estrogen modulates expression and function of G-protein-coupled receptors. The goal of this study was to assess the effect of 17β-estradiol (10 nM) exposure for 1 (E1) or 6 (E6) days on density and function of hMT1 and hMT2 melatonin receptors expressed in Chinese hamster ovary (CHO) cells (CHO-MT1/CHO-MT2 cells). This strain of CHO cells expressed both estrogen receptor alpha and beta mRNAs, as determined by RT-PCR amplification. 17β-Estradiol treatment did not modify the affinity of either receptor; however, it significantly increased the density of 2-[125I]iodomelatonin-binding sites in CHO-MT2 cells. 17β-Estradiol treatment (1–6 days) did not affect the potency of melatonin to inhibit forskolin stimulation of cAMP formation through activation of either MT1 or MT2 receptors; however, it significantly attenuated the maximal inhibition of forskolin-stimulated cAMP formation induced by melatonin (0.01–1 µM) in CHO-MT1 cells. Melatonin stimulation of [35S]GTPγS binding to CHO-MT1 cell membranes was also attenuated following estradiol treatment. The inverse agonist luzindole reduced basal [35S]GTPγS binding in estradiol-treated cells but not in control CHO-MT1 cells, suggesting that estradiol promotes constitutive activity of MT1 melatonin receptors. We suggest that 17β-estradiol differentially affects MT1 and MT2 melatonin receptor functions, attenuates melatonin responses through activation of MT1 receptors, and increases the MT2 receptors density.
How to Develop Successful Hospitality Innovation
Authors: Ottenbacher Michael , Gnoth Juergen
Published: April 2005

A survey of 184 German hoteliers identified nine factors that promote successful service innovations. The study found that the nature of the innovation is far less important than the effectiveness of a hotel’s human resources management and employee training, empowerment, and commitment to the service. Ensuring that the innovation is matched to the targeted market is important, of course, but such factors as effective marketing communication and public relations do not seem to support innovations’ success. Also important is the tangible nature of the service, but having innovative technology was not a significant factor in new-service development for these hoteliers.
Local versus Foreign Workers in the Hospitality and Tourism Industry
Authors: Sadi Muhammad Asad , Henderson Joan C.
Published: April 2005

For the past thirty years, the Kingdom of Saudi Arabia has relied heavily on immigrant and expatriate workers in many industries, most notably hospitality and tourism. Growing unemployment among Saudi nationals, however, has caused the government to implement a policy of Saudization, which mandates that expatriates are to be replaced by local workers. The implications for the hotel and tourism industry are twofold. First, immigrant workers have been called on to fill many jobs for which the pay is too low for local residents or jobs that nationals would prefer not to do. Second, the hotel industry has long relied on expatriate managers for technical expertise, which now must be transferred to Saudi citizens.
Hotel Reform in China
Authors: Yu Larry , Huimin Gu
Published: April 2005

The hotel industry in China is currently going through fundamental reform in ownership structure and development. A SWOT (strengths, weaknesses, opportunities, and threats) analysis as reforms go forward reveals development opportunities as well as vulnerabilities to internal organizational and external environmental changes. Notable strengths include a growing market and the government’s push to upgrade all hotel standards. Weaknesses include an overleveraged industry that has long been operated inefficiently by government entities. New and reinvigorate operators have great opportunities in this situation, as do those who offer ancillary services and management education. The greatest foreseeable threat is an economic slowdown or other event that interferes with tourist growth. With the 2008 Olympiad to be held in Beijing and a World Expo slated for Shanghai in 2010, such a downturn would most likely be temporary—meaning that the Chinese hotel industry has excellent prospects overall.
Doing Business in the People’s Republic of China
Authors: Kivela Jaksa , Leung Lin Fung-Lin
Published: April 2005

A variety of barriers face foreign joint venture (JV) operators in the People’s Republic of China (PRC). Among these are issues that relate to business and investment laws and regulations, which by default include the foreign investment enterprise (FIE) business vehicles. In this context, one could argue (and legal experts tend to agree) that unless a suitable business vehicle is selected by the FIE, or if the FIE is not correctly set up, the venture may become highly vulnerable to closure and possible litigation, irrespective of whether the organization is well managed. The most likely route for international hotel executives to establish a foreign business venture in the PRC is via a JV. The key to establishing a JV is appropriately conducted business negotiations with prospective Chinese partners.
Behind the Stars
Authors: Johnson Colin , Surlemont Bernard , Nicod Pascale , Revaz Frederick
Published: April 2005

The Michelin star system in Europe is the best-known and most respected ranking system for high-quality or haute cuisine restaurants. This study examines Michelin’s grading procedures and how chefs and restaurateurs perceive the ranking system and the Michelin awards. The study surveyed chefs in thirty-six restaurants ranked as having two or three Michelin stars over the period of ten years in France, Belgium, the United Kingdom, and Switzerland. The chefs identified the following key factors that attributed to the success of their restaurants: investment and investment types, sources of financing, pursuit of excellence, and culinary craftsmanship involved. While the Michelin star chefs were tremendously successful as culinary artisans, this study revealed that the financial success of the Michelin star-rated restaurants was far more heterogeneous.
Hotel and Tourism Development in Cuba
Authors: Cerviño Julio , Cubillo José María
Published: April 2005

In the past ten years, Cuba has recorded the highest rate of growth in tourism arrivals of all Caribbean countries to become the third most popular tourism destination in the Caribbean region and the second destination in the region for Europeans. In the process, tourism has become Cuba’s most lucrative sector. Based on in-depth interviews with senior executives of Cuban and foreign international hotel chains operating on the island and desk research in and outside Cuba, it appears that the benefits for international operators in Cuba outweigh the risks involved. With its expansion of infrastructure and promotion of its history and ecotourism, the country will continue to play a major role as a tourist destination in the Caribbean, regardless of whether the U.S. embargo remains in place.
Limited Equity Housing Cooperatives: Defining a Niche in the Low-Income Housing Market
Authors: Saegert Susan , Benítez Lymari
Published: April 2005

This article examines the concept of limited equity housing cooperatives (LECs) and their potential niche in the housing stock of the United States. The authors discuss problems related to the success of housing cooperatives, as well as policy implications and opportunities for development of LECs. The research evidence that exists shows that LECs have a strong record of providing high-quality, safe, affordable housing for low- and moderate-income populations. The authors conclude that LECs constitute a valuable, if underused, form of housing ownership with the potential to improve the quality of life for certain low- and moderate-income households and to contribute to the physical and social quality of the larger community.
Urban Form and a Child’s Trip to School: The Current Literature and a Framework for Future Research
Authors: McMillan Tracy E.
Published: April 2005

Recently created policies and programs target urban form as a primary factor in changes in children’s travel behavior to school. Unfortunately, little research exists that supports a direct relationship between urban form and a child’s trip to school. This article first discusses the transportation and health problems these policies attempt to address. It then reviews the current planning and public health literature on the relationship between urban form and children’s travel behavior. Finally, a conceptual framework is outlined that addresses the complexity of the relationship between urban form and a child’s trip to school to guide future policy and research.
Pharmacokinetic Alterations of Antimicrobials in the Critically Ill
Authors: Cook Aaron M.
Published: April 2005

Critical illness is accompanied by multiple physiologic alterations that affect the pharmacokinetics of antimicrobials. Although the pharmacokinetics of a number of antimicrobials have been studied in critically ill individuals, an understanding of the physiological alterations in critical illness and general pharmacokinetic principles of antimicrobials is imperative for appropriate selection, dosing, and prediction of toxicity.
Infection Control in Intensive Care Units
Authors: Mohr John , Peninger Michelle , Ostrosky-Zeichner Luis
Published: April 2005

For patients in intensive care units, the development of an infection is associated with an increase in morbidity, mortality, and cost. These infections are largely preventable through the implementation of infection control programs. Infection control programs must focus on 3 general strategies: (1) prevention of health care-associated infections, (2) containment of pathogens that pose a health risk and/or are resistant to routine antibiotics, and (3) development of strategies to limit the emergence of resistant microorganisms through optimal and appropriate antimicrobial utilization. The purpose of this article is to review these 3 general strategies.
Acute Respiratory Distress Syndrome
Authors: Burleson Brian S. , Maki Erik D.
Published: April 2005

Acute lung injury is a syndrome diagnosed clinically and is one of the most common causes of respiratory failure seen in the intensive care unit. A consensus definition of this and its more severe form, acute respiratory distress syndrome (ARDS), has allowed for better consistency in determining the epidemiology and facilitates consistent clinical trial design to better find therapies to treat or prevent it. Patients who present with ARDS usually show signs of tachpnea or dyspnea and have underlying conditions that promote inflammatory responses. The pathogenesis involves an inflammatory insult that eventually destroys the pulmonary capillary vasculature as well as alveoli. Pathophysiologically, the patient with ARDS may progress through as many as 3 phases: exudative, proliferative, and fibrotic. Treatment options can be either nonpharmacologic or pharmacologic and are limited. Ventilator strategies such as low-tidal-volume ventilation have improved outcomes in these patients, while corticosteroid use is not as established to provide morbidity or mortality benefit. Other therapies have been investigated with inconclusive or disappointing results for the treatment of this fatal syndrome.
Considerations for the Management of Gram-Positive Pathogens in the Intensive Care Unit
Authors: Schriever Christopher , Zeitz-Colaizzi Laurie , Quinn Andrea , Schriever Allison E. , Cannon Joan P.
Published: April 2005

Surveillance data demonstrate that the majority of gram-positive bacterial isolates obtained in the intensive care unit (ICU) setting are staphylococci and enterococci. Staphylococci, mainly Staphylococcus aureus and coagulase-negative staphylococci, compose the majority of clinical isolates. Data from 25 North American ICUs reported methicillin-resistant Saureus (MRSA) in more than 50% of the Saureus organisms isolated mainly from a respiratory source. In addition to MRSA, Saureus with reduced susceptibility to vancomycin has been reported. Enterococci are typically considered opportunistic pathogens, infecting immunocompromised hosts. Resistance of enterococci to vancomycin, along with the newer gram-positive antimicrobials, is an increasing problem. Investigators have demonstrated that nearly 30% of enterococci isolated in the ICU are resistant to vancomycin. The high level of resistance and limited therapeutic options make treating resistant gram-positive organisms such as MRSA and vancomycin-resistant enterococci particularly problematic. While vancomycin has long been considered the gold standard for the treatment of resistant gram-positive infections, newer agents (eg, quinupristin-dalfopristin, linezolid, and daptomycin) offer therapeutic alternatives.
Photooxidized Polysilane Binders for Low Temperature Fabrication of Dye-sensitized Solar Cells
Authors: Soeda Kuniko , Kosugi Daishi , Kado Takashi , Hayase Shuzi
Published: April 2005

Photooxidized polysilanes were evaluated as binders connecting nano-TiO2 particles for low temperature baking process. Both of Jsc and Voc increased after TiO2 nanoparticles (P25) were connected with photooxidized polysilanes. The amount of dyes adsorbed on TiO2 layers, TiO2 flat band potentials, electron diffusion co-efficient, electron life time were measured. The increases in the Jsc and Voc were associated with increases in electron diffusion coefficients and electron life time in TiO2 layers.
Bifunctional Fe3O4/CdS Nanocomposites Synthesized by Surface-initiated Atom Transfer Radical Polymerization
Authors: An Lijuan , Li Zhaoqiang , Wang Zheng , Zhang Junhu , Yang Bai
Published: April 2005

This paper described the fabrication of a new Fe3O4/CdS nanocomposite. PCd(MA)2 was firstly polymerized by surface-initiated atom transfer radical polymerization (ATRP) on the surface of Fe3O4 nanoparticles, and then the formation of CdS nanoparticles took place in situ when S2− ions were released by thioacetamide upon heating. The nanocomposites were characterized by XPS, TEM, and UV–vis. The PL and magnetic properties were also studied.
Thermolysis and Photolysis of Stable Se-Nitrososelenols
Authors: Shimada Keiichi , Goto Kei , Kawashima Takayuki
Published: April 2005

The thermal reactivity and photoreactivity of Se-nitrososelenols have been elucidated by using stable compounds protected by bowl-type substituents. Thermolysis of Se-nitrososelenol 1 afforded diselenide 3, the structure of which was determined by X-ray crystallography, while tetraselenide 13 was obtained as the major product in photolysis of 1.
A Highly Potent Insulin–mimetic Zinc(II) Complex with a Zn(S2O2) Coordination Mode: Bis(1,6-dimethyl-3-hydroxy-5-methoxy-2-pentyl-1,4-dihydropyridine-4-thionato)zinc(II)
Authors: Adachi Yusuke , Yoshida Jiro , Kodera Yukihiro , Sakurai Hiromu
Published: April 2005

Zn(II) complexes of allixin and its sulfur and N-methyl analogs were newly prepared, and their insulin–mimetic activities were evaluated. Among them, a new bis(1,6-dimethyl-3-hydroxy-5-methoxy-2-pentyl-1,4-dihydropyridine-4-thionato)zinc(II) complex exhibited the most potent insulin–mimetic activity (IC50 = 11 μM) in terms of inhibition of free fatty acid release in adipocytes.
Hydrogen Production from Biomass-Ethanol at Ambient Temperature with Novel Diaphragm Reactor
Authors: Sekine Yasushi , Asai Shinjiro , Urasaki Kouhei , Matsukata Masahiko , Kikuchi Eiichi , Kado Shigeru , Haga Fumihiro
Published: April 2005

We used a novel liquid-fuel-reforming system, with a diaphragm and discharge hybrid apparatus that can be operated under ambient temperature and atmospheric pressure, to obtain 50% hydrogen by steam reforming of ethanol with high energy efficiency of up to 95%.
Template-free Hydrothermal Synthesis of High Surface Area Nitrogen-doped Titania Photocatalyst Active under Visible Light
Authors: Rhee Chang Houn , Bae Sang Won , Lee Jae Sung
Published: April 2005

The nanofibrous ammonium titanate (NH4)2Ti3O7−xNx was hydrothermally synthesized by a new method proposed here from titanium oxysulfate precursor in a NH4OH solution under hydrothermal conditions at 393 K without any extra templates. The calcination of the as-synthesized material at 673 K produced nitrogen-doped titania (TiO2−xNx) with anatase phase, which absorbed visible light and had an extremely high surface area (377 m2g−1). This material showed an excellent photocatalytic activity in decomposition of 2-propanol under visible light irradiation.
Oxidative Coupling Polymerization of 2,6-Dimethylphenol with a Copper–Amine Catalyst Immobilized within the Interior of SBA-15
Authors: Shibasaki Yuji , Nakamura Masahiro , Ishimaru Ryuhei , N. Kondo Junko , Ueda Mitsuru
Published: April 2005

An effective method to control polydispersity (Mw/Mn) in the oxidative coupling polymerization of 2,6-dimethylphenol has been developed. SBA-15 functionalized with N,N,N′-trimethyl-N′-trimethoxysilylpropylethylenediamine and copper chloride(I) produced a polymer with the number average molecular weight (Mn) of 44000 and Mw/Mn of 3.9, when the polymerization was conducted in toluene/pyridine (5/1 volume ratio) at 40 °C for 12 h under oxygen atmosphere. The conventional catalytic system [CuCl(I)–pyridine] afforded the polymer with Mn of 81000 and Mw/Mn of 40, indicating the effectiveness of the mesoporous catalyst.
Ruthenium-catalyzed Isomerization of Alkenol into Alkanone in Water under Irradiation of Microwaves
Authors: Ishibashi Kenichi , Takahashi Masaaki , Yokota Yutaka , Oshima Koichiro , Matsubara Seijiro
Published: April 2005

Ruthenium catalyzed isomerization of alkenol into alkanone through a migration of C–C double bond was performed in water under irradiation of microwaves. When the reaction was performed in deuterium oxide instead of water, the trail of the migration was shown by H–D exchange reaction.
Mass Spectrometry as a Tool for the Determination of Heats of Tautomerization of Thioamides in the Gas Phase
Authors: Allegretti P.E. , Milazzo C.B. , Furlong J.J.P.
Published: April 2005

Tautomerism of several thioamides was studied by mass spectrometry. The analysis of the corresponding mass spectra allowed some fragmentations to be assigned to specific tautomers and heats of tautomerization to be determined through temperature effects and electron energy studies. Experimental determinations were strongly supported by theoretical calculations. AM1 semi-empirical results indicate that the thioamide–thioimidol equilibrium can be studied by mass spectrometry. Also, additional evidence was obtained regarding tautomerism occurrence between neutral species.
Probing the Stability and Structure of Metalloporphyrin Complexes with Basic Peptides by Mass Spectrometry
Authors: Jellen Emily E. , Ryzhov Victor
Published: April 2005

The stability and structure of non-covalent complexes of various peptides contatining basic amino acid residues (Arg, Lys) with metalloporphyrins were studied in a quadrupole ion trap mass spectrometer. The complexes of heme and three other metalloporphyrins with a variety of basic peptides and model systems were formed via electrospray ionization (ESI) and their stability was probed by energy-variable collision-induced dissociation (CID). A linear dependence for basic peptides and model compounds/metalloporphyrin complexes was observed in the plots of stability versus degrees of freedom and was used to evaluate relative bond strength. These results were then compared with previous data obtained for complexes of metalloporphyrins with His-containing peptides and peptides containing no basic amino acids. The binding strengths of Lys-containing peptide complexes in the gas phase was found to be almost as strong as that of Arg-containing complexes. Both systems showed stronger binding than His-containing peptides studied previously. To probe the structure of Arg and Lys non-covalent complexes (charge solvation versus salt bridges), two techniques, CID and ion–molecule reactions, were used. CID experiments indicate that the gas-phase complexes are most likely formed by charge solvation of the central metal ion in the metalloporphyrin by basic side chains of Arg or Lys. Results from the ion–molecule reaction studies are consistent with the charge solvation structure as well.
Collision-Induced Dissociation of Peptide Thioesters: The Influence of Peptide Length on Fragmentation
Authors: Buré Corinne , Boujard Olivier , Bertrand Marylène , Lange Catherine , Delmas Agnès F.
Published: April 2005

Five peptide thioesters of increasing length were fragmented using two processes, in-source and in-collision cell fragmentation, using an electrospray source coupled to a triple quadrupole mass spectrometer. Comparison of their fragmentations was made in regard to their length. The two fragmentation conditions show that the peptide length has no influence on structural information and that the fragmentation efficiency is higher for the smallest peptides than for the longest. The particularity of these peptide thioesters consists of the neutral loss of ethanethiol. The absence of the a3 fragment ion and the presence of the (a3–17) ion on the collision-induced dissociation mass spectra are noted.
Identification of Flavonoids and Their Glycosides by High-Performance Liquid Chromatography with Electrospray Ionization Mass Spectrometry and with Diode Array Ultraviolet Detection
Authors: Liang Qingrong , Qian He , Yao Weirong
Published: April 2005

Identification of flavonoids and flavonoid glycosides was carried out on Psidium guajava Linn leaves by means of high-performance liquid chromatography ultraviolet (HPLC-UV) analysis and HPLC mass spectrometry. By using HPLC-UV, two known phenolics (gallic acid and quercetin) and five newly reported ones (procatechuic acid, chlorogenic acid, caffeic acid, kaempferol and ferulic acid) were identified in alcohol guava leaf extract. Structural information about the compounds was obtained from the retention times, the UV spectra and mass spectra without the need to isolate the individual compounds. Two flavonoids (quercetin and kaempferol) and four flavonoid glycosides (three known components, quercetin 3-O-alpha-L-arabinoside, quercetin 3-O-beta-D-glucoside and quercetin 3-O-beta-D-galactoside, along with one novel compound, kaempferol-glycoside) and three other unknown compounds have been identified in the fractions.
Waveboard Artifacts Generate Ghost Resonances Consistent with Equations for Predicting Ion Motion in Commercial Quadrupole Ion Traps
Authors: Sichilongo Kwenga F. , Lynn Bert C.
Published: April 2005

Real-time experiments involving fragmentation of the precursor molecular ion of n-butylbenzene ( m/z 134) to produce product ions C7H+7 ( m/z 91) and C7H+8 ( m/z 92), were used to observe the motion of ions in a commercial quadrupole ion trap. Initially, ghost resonance peaks were observed for excitation of the precursor ion at qz values of 0.4 and 0.5 on the qz axis of the stability diagram. Further experiments involving the generation of two-dimensional contour plots confirmed that these ghost peaks, which were in agreement with mathematical equations describing the motion of ions in a quadrupole field, arose due to waveboard artifacts. Two-dimensional contour surface plots showed non-linear secular frequency canyons from a qz value of 0.5 to higher values corresponding with higher drive radio frequency (rf) voltages on the stability diagram. This observation confirmed that ions are subjected to non-linear effects in this mass scan range. The octapole and hexapole field lines were observed at qz values of 0.65 and 0.78, respectively.
Derivatization in Mass Spectrometry—5. Specific Derivatization of Monofunctional Compounds
Authors: Halket John M. , Zaikin Vladimir G.
Published: April 2005

The present paper is complementary to the foregoing reviews and describes some additional methods of the derivatization of particular functional groups mainly to enhance the structural information content of electron ionization and chemical ionization mass spectra. Derivatization approaches for the modification of unsaturated compounds, alcoholic, carboxylic, carbonyl, amine and other functional groups, are discussed. Derivatization for separation and quantitative determination of chiral enantiomeric compounds is also considered. Preliminary chemical and physical–chemical degradation for structure elucidation of high molecular weight compounds (biopolymers, synthetic polymers) is mentioned. Chemical aspects of derivatizations and characteristic mass spectral features of derivatives are described briefly. Some particular applications of chemical modification, in conjunction with mass spectral measurements for the analysis of various important bioorganic compounds and compounds in biological fluids, air, environmental etc., are considered.
Multiple Tandem Mass Spectrometry-Based Investigation of the Behaviour of Some Thiazol-Benzimidazolones and 2-Benzimidazolylsulphanyl Ethanones
Authors: Vogliardi Susanna , Anichina Kameliya , Stoyanova Rossitza , Traldi Pietro
Published: April 2005

The behaviour in electrospray conditions of a series of thiazol-benzimidazolones and 2-benzimidazolylsulphanyl ethanones has been studied by means of multiple tandem mass spectrometry experiments. Even though the experimental conditions were the same, different behaviour is observed for the two classes of compounds. In the case of thiazol-benzimidazolones, the formation of a protonated complex with CH3OH employed as solvent is observed, but in the case of 2-benzimidazolylsulphanyl ethanones the formation of MNa+ ions is privileged. This behaviour has been related to molecular structure. The collisionally-induced decompositions of MH+ ions have been rationalised in terms of the Stevenson–Audier and even-electron rules, as well as on the basis of proton affinity data. Thus, protonated thiazol-benzimidazolones undergo facile loss of CO and a series of different decomposition pathways involving cleavage of the thiazolone ring that reflect the structure of the neutral fragments. In contrast, the decompositions of the protonated 2-benzimidazolylsulphanyl ethanones are mainly related to the piperazine moiety, suggesting that the protonation takes place on this substructural unit.
Updating Evidence for Cationization of Polymers in the Gas Phase during Matrix-Assisted Laser Desorption/Ionization
Authors: Hanton Scott D. , Owens Kevin G. , Chavez-Eng Cynthia , Hoberg Anne-Mette , Derrick Peter J.
Published: April 2005

Matrix-assisted laser desorption/ionization (MALDI) techniques have been developed to determine the chemical structure of a variety of industrial polymers. Despite the enormous popularity and power of MALDI, the details of the cationization mechanisms of the process are currently rather poorly understood. The MALDI cationization of polymer analytes was investigated previously by Hoberg and co-workers.1 They used layered samples to explore the role of gas-phase cationization in MALDI of polymers. This paper seeks to extend the work initiated by Hoberg and co-workers and update the results of the earlier work. The new experiments take advantage of a MALDI instrument with delayed extraction and show that separation in the initial acceleration region of the mass spectrometer is not a key component of cationization. Investigations of tri-layer samples by time-of-flight secondary ion mass spectrometry (ToF-SIMS) also show that there is considerable interaction among the layers. These interactions, specifically the solubility of the salts in the solvents, account for the presence of the bottom layer cation in the mass spectra. The absence of the top layer cation in the mass spectra is due to the inability of the polymer oligomers to penetrate that layer during desorption.
Mass Spectral Studies on Synthetic Analogs of Organophosphorus Toxin Occurring in Dinoflagellate Algae
Authors: Gupta Arvind K. , Palit Meehir , Dubey Devendra K. , Raza Syed K.
Published: April 2005

A series of organophosphorus compounds related to PB-1 toxin [O,O-diphenyl N-cyclooctylphosphoramidate] occurring in dinoflagellate algae as fish toxin have been synthesized and subjected to mass spectral studies under electron ionization. The fragmentation pattern obtained for the compounds has been substantiated by performing tandem mass spectrometry experiments in product ion scan mode.
Characterization of Electrospray Ionization Mass Spectrometry for N-Diisopropyloxyphosphoryl Dipeptide Methyl Esters
Authors: Luo Shi-Zhong , Li Yan-Mei , Niu Yan-Ling , Chen Yi , Jiang Yu-Yang , Chen Jing , Zhao Yu-Fen
Published: April 2005

A systematic study of the fragmentation pattern of N-diisopropyloxyphosphoryl (DIPP) dipeptide methyl esters in an electrospray ionization (ESI) tandem mass spectrometry (MS/MS) was presented. A combination of accurate mass measurement and tandem mass spectrometry had been used to characterize the major fragment ions observed in the ESI mass spectrum. It was found that the alkali metal ions acted as a fixed charge site and expelled the DIPP group after transferring a proton to the amide nitrogen. For all the N-phosphoryl dipeptide methyl esters, under the activation of a metal ion, the rearrangement product ion at m/z 163 was observed and confirmed to be the sodium adduct of phosphoric acid mono-isopropyl esters (PAIE), via a specific five-membered penta-coordinated phosphorus intermediate. However, no rearrangement ion was observed when a β-amino acid was at the N-terminal. This could be used to develop a novel method for differentiating isomeric compounds when either α- or β-amino acid are at the N-terminus of peptides. From the [M + Na]+ ESI-MS/MS spectra of N-phosphoryl dipeptide methyl esters (DIPP – Xaa1 – Xaa2 – OMe), the peaks corresponding to the [M + Na – Xaa1 – C3H6]+ were observed and explained. The [M + Na]+ ESI-MS/MS spectra of N-phosphoryl dipeptide methyl esters with Phe located in the C-terminal, such as DIPP–Val–Phe–OMe, DIPP–Leu–Phe–OMe, DIPP–Ile–Phe–OMe, DIPP–Ala–Phe–OMe and DIPP–Phe–Phe–OMe, had characteristic fragmentation. Two unusual gas-phase intramolecular rearrangement mechanisms were first proposed for this fragmentation. These rearrangements were not observed in dipeptide methyl ester analogs which did not contain the DIPP at the N-terminal, suggesting that this moiety was critical for the rearrangement.
Visuelles Orientierungsverhalten auf Webseiten (Visual Orientation Behavior on Web Pages)
Authors: Ollermann Frank , Reinecke Stefan , Hamborg Kai-Christoph
Published: April 2005

In einer Blickbewegungsstudie mit N = 70 Internetnutzern wurden Wahrnehmungsprozesse in der Orientierungsphase bei der Betrachtung von Internetseiten untersucht. Die Ergebnisse zeigen, dass je nach Art der betrachteten Website unterschiedliche Seitenelemente zur ersten Orientierung dienen. Die Befunde machen unter anderem deutlich, dass sich Ergebnisse von Blickbewegungsstudien, die sich nur auf eine Art von Website stützen, nicht auf Websites im Allgemeinen übertragen lassen.
Zur Gebrauchstauglichkeit von Handys – Breite Untersuchung und aktueller Stand (On the Usability of Mobile Phones – Broad Study and Status Quo)
Authors: Dahm Markus , Felken Christian , Klein-Bösing Marc , Rompel Gert , Stroick Roman
Published: April 2005

In einem Handy der Größe einer Zigarettenschachtel sind dutzende komplexe Funktionen untergebracht, eine Meisterleistung der Ingenieure. Leider sind diese immer mehr Funktionen immer schlechter nutzbar. Dies wird auf mangelnde Aufgabenangemessenheit, fehlende Erwartungskonformität und schlechte Selbsterklärungsfähigkeit zurückgeführt. In einer breit angelegten Untersuchung mit 1300 Teilnehmern wurde die Gebrauchstauglichkeit von modernen Handymodellen untersucht. Die Aufgaben wurden mittels einer internetbasierten Simulation bearbeitet und auch online ausgewertet. Es konnte nicht nur gezeigt werden, dass Handys für Anfänger schwer zugänglich sind, sondern auch dass selbst so eingeschätzte Experten Schwierigkeiten bei unbekannten Funktionen und fremden Handys haben. Zum Abschluss werden einige Verbesserungsansätze diskutiert.
Verteilte Wissensorganisation mit Semantischen Räumen (Distributed Knowledge Organization with Semantic Spaces)
Authors: Hampel Thorsten , Keil-Slawik Reinhard , Selke Harald
Published: April 2005

Der Begriff Wissensgesellschaft verdeutlicht die enorme Bedeutung, die der Erzeugung, Nutzung und Pflege von Wissensbeständen heute zukommt. In Bezug auf den Wissensbegriff hat sich mittlerweile die Einsicht durchgesetzt, dass Wissen weitgehend sozial eingebettet ist. Dies gilt insbesondere auch für die Strukturierung von Wissen. Neben der lexikografischen Erschließung über Stichworte oder Metadaten kommt der grafischen Strukturierung bei der netzgestützten Wissensorganisation eine besondere Bedeutung zu. Der Beitrag gibt zunächst einen Überblick über Methoden zur grafischen Strukturierung von Wissen. In einem nächsten Schritt werden dann Techniken zur räumlichen Strukturierung kooperativer virtueller Wissensräume vorgestellt. Als wesentlich erweisen sich dabei die gewählte Form der Persistenz, die Unterstützung sowohl synchroner als auch asynchroner Arbeitsprozesse und Mechanismen der gegenseitigen Wahrnehmung. Des Weiteren sind Übergänge zwischen individuellen und kooperativen Arbeitsphasen sowie Möglichkeiten zur Selbstorganisation von zentraler Bedeutung. Mit Hilfe dieser Techniken ist es sowohl möglich, Wissensrepräsentationen aufzubauen und zur Verfügung zu stellen als auch Diskursprozesse zu strukturieren. Beide Möglichkeiten mit ihren neuen didaktischen Möglichkeiten werden anhand praktischer Beispiele in der universitären Ausbildung vorgestellt.
Interaktion im Sensoric Garden – eine Design-Reflexion (Interaction in a Sensoric Garden – a Design Reflection)
Authors: Hornecker Eva , Bruns Friedrich W.
Published: April 2005

Als Beispiel einer interaktiven Mixed Reality Umgebung beschreiben wir den „Sensoric Garden“, sieben während eines Bremer Festivals gezeigte Installationen. Da solche Ereignisse sich nicht in Bezug auf Benutzbarkeit oder Effektivität bewerten lassen, benötigen wir andere Kriterien, um die Attraktivität der Installationen für Besucher zu erklären. Kategorien und Konzepte aus dem Diskurs um Interaktionsdesign und Interaktivität erwiesen sich als hilfreich in einer Design-Reflexion dazu, was einige Stationen zu einem Erfolg werden ließ und weshalb andere nicht die an sie gesetzten Erwartungen erfüllten und wenig Aufmerksamkeit erhielten.
Ultrasonic, Volumetric and Viscometric Studies of Molecular Interactions in Binary Liquid Mixtures of Hexadecane with 1-Pentanol, 1-Hexanol, and 1-Heptanol at (298, 308 and 318) K
Authors: Mehra Rita
Published: April 2005

Ultrasound speed (U), density (ρ) and viscosity (η) have been measured for pure liquids and their binary mixtures formed from hexadecane with 1-pentanol, 1-hexanol, and 1-heptanol at (298, 308 and 318) K covering the entire mole fraction range of hexadecane. From the experimental data, adiabatic compressibility (K
s), intermolecular free length (L
f), molar sound speed (R
m), acoustic impedance (Z), excess adiabatic compressibility (K
s
E), excess free volume (V
f
E), excess viscosity (ηE), Gibbs energy of activation of viscous flow (G
*E) and interaction parameter (α) have been computed. These parameters are used to discuss the nature and extent of intermolecular interactions between the component molecules. Temperature variation also provides an opportunity to study the effect of temperature on the extent of intermolecular interactions between the component molecules of liquid mixtures. All the excess functions studied are fitted to Redlich–Kister relation to estimate the adjustable parameters alongwith their standard deviations.
Characteristic Lattice Complexes
Authors: Hauck J. , Mika K.
Published: April 2005

2D and 3D lattice complexes with increased self-coordination numbers Ti
, i = 1–3, of nearest, second and third neighbors were derived for characteristic Wyckoff sets with zero or one parameters. Structure types of adsorbed atoms in 2D or elements A in 3D and A
x
B
y
compounds are approximated to the list of lattice complexes. Covalent bonding or electronic effects of atoms like lone electron pairs or Jahn–Teller distortion give rise to deviations from lattice complexes. Homogeneous structures A
x
B
y
with identical A–A or B–B self-coordination numbers T
1, T
2, T
3 of nearest, next-nearest and third neighbors are selected for different systems like magnetic ordering with A = ⊕ and B = ⊖ spin direction or crystals of organic molecules with different orientations.
Excellent Performance of La1−xCexSrNiO4 (x ≤ 0.3) for NO Decomposition in the Presence of Excess Oxygen
Authors: Zhu Junjiang , Xiao Dehai , Li Jing , Yang Xiangguang , Wu Yue
Published: April 2005

Ce involved perovskite-like oxides (La1−xCexSrNiO4, x ≤ 0.3) show high activity for NO decomposition even in the presence of excess oxygen, which might be mainly ascribed to the new active site formed in the catalyst due to the entry of Ce to the La site of LaSrNiO4.
Viscosity of the System KF–K2NbF7–Nb2O5
Authors: Cibulková Jarmila , Chrenková M.
Published: April 2005

The viscosity of melts of the system KF–K2NbF7–Nb2O5 has been measured using computerized torsion pendulum method. An equation describing the dependency of the viscosity in logarithm values on composition at 1173 K was calculated by multiple linear regression analysis. The sum of viscosities of pure components in logarithm values multiplied by their mole fraction was used as an “additive” behaviour. In the concept of modified Redlich–Kister's type equation binary interactions of the particular components were found.
A Characteristic Effect of Pressure on the Inclusion Complexation of Modified β-Cyclodextrins with 4-Substituted Phenols
Authors: Sueishi Yoshimi , Ide Tatsuhiro
Published: April 2005

The equilibrium constants for the inclusion complexation of two kinds of modified β-cyclodextrins (heptakis-(2,6-di-O-methyl)-β-cyclodextrin (DM-βCD) and heptakis-(2,3,6-tri-O-methyl)-β-cyclodextrin (TM-βCD)) with 4-substituted phenols were determined at high pressures. A characteristic pressure effect was found in the inclusion equilibria of modified β-CDs. As the external pressure increases, the inclusion equilibrium constants for the phenols/TM-βCD system increased remarkably, while the effect of pressure for the phenols/DM-βCD system was small. The reaction volumes for the CD inclusion complexation with 4-substituted phenols were estimated from the pressure dependence of the inclusion equilibria: ΔV = −14.9∼−33.4 cm3 mol−1 for the phenols/TM-βCD system and −2.7∼8.6 cm3 mol−1 for the phenols/DM-βCD system. Analysis of the effect of pressure on the inclusion complexation with DM- and TM-βCDs revealed that there is a pressure-dependent competing complexation between included phenols and water molecules, and the number of water molecules included in the DM- and TM-βCD cavities in water was estimated.
Agricultural Water Use Efficiency (
WUE
) and Productivity (
WP
)
Authors: Steduto Pasquale
Published: April 2005

Among the different sectors of society, agriculture represents the major water consumer. Rain‐fed and irrigated agriculture uses water at various degrees of
efficiency
, resulting in different levels of
productivity
.

The general term
efficiency (e)
indicates the ratio of
output
to
input
of variables (Eq. 1) associated with
transformation
(e.g., of energy) or
transport
(e.g., of mass and energy)
processes
:

urn:x-wiley:9780471478447:media:aw29:xm1

The
efficiency
term (
e
) has two peculiarities: (1) the units are nondimensional and (2) the values are always between the theoretical limits of 0 and 1. In water use, the efficiency (
e

w

) has water amounts (e.g., volumes, quantities, or depth) in both
input
and
output
variables.

The general term
productivity
(
p
) still indicates a ratio of output to
input
of variables, as in Equation 1, but these
output
and
input
variables are not associated with
transport processes
and might be associated, but not necessarily, with a
transformation process
. The consequent peculiarities of the
productivity
term (
p
) do not match those of the
efficiency
term (
e
), that is, the units are dimensional, and the theoretical limits of 0 and 1 are lost. In water use, the productivity term (
p

w

) has water amounts (e.g., volumes, quantities, or depth) only in the
input
. The
output
, instead, generally takes the form of quantities produced: physical (e.g., dry matter or final yield of crops, or meat or dairy products from animal husbandry, etc.), economic (e.g., gross income, net revenue, etc.), or any other form.

The efficiency term
e

w

has to do more with the way water is used by the system, whereas
p

w

has to do more with the outcome from the system per unit of water it consumes. Nevertheless, it turns out that a change in
e

w

is reflected in a change in
p

w

, implying that there is a link between
e

w

and
p

w

, though the reverse is not the case. Moreover, though
p

w

cannot be strictly defined by Equation 1, it still resembles a sort of efficiency of the system to produce a given
output
for a given
input
. The undefined degree of commonality and distinction between
e

w

and
p

w

has led to some confusion in investigating agricultural water use.
Soil Phosphorus Availability and Its Impact on Surface Water Quality
Authors: Sarkar Dibyendu
Published: April 2005

Phosphorus (P) is ubiquitous in soils and is an essential element for plant and animal growth. Without enough soil P, crop yields will be low. However, excess soil P may become a part of surface runoff and can accelerate eutrophication of receiving fresh waters. Eutrophication has been identified as the main problem in U.S. surface waters that has impaired water quality. Although P and nitrogen (N) both influence eutrophication, P is generally the limiting nutrient in freshwater bodies. The degree of P input in surface waters depends on the soil availability of P and the degree of transport of dissolved and particulate P, especially in agricultural lands that have been fertilized for a long period of time. The availability of P in soils is controlled by various factors, such as soil pH, clay content, soil organic matter, amorphous Fe/Al oxide and carbonate content, soil moisture content, and degree of soil compaction. The amount of available P is generally estimated by a variety of soil‐test methods, including both chemical extractants and nondestructive techniques simulating plant root action. Phosphorus transport from the source to surface waters is controlled by the rate of erosion and surface runoff. Hence, reducing P loss in agricultural runoff may be brought about by implementing proper source and transport control strategies. Popular source control techniques include soil P management, estimating thresholds for environmental risk assessment, manure management, and refining feed rations, common transport management techniques include conservation practices such as reduced tillage, cover crops, and buffer strips in critical areas of P export from a watershed.
Sprinkler Irrigation
Authors: Asghar Muhammad Nadeem
Published: April 2005

In recent decades, various sprinkler irrigation methods and installations have been developed to meet the needs of farmers, particularly smallholders. Hand‐move sprinkler irrigation is the most widely adopted and least expensive system operated with pressure ranges from 2.0–3.5 bars. The sprinklers are mounted on lateral pipelines temporarily laid across a field. To reduce labor requirements, this system was modified to hose‐move sprinkler irrigation. In this modified system, lateral pipelines are placed permanently, and the sprinklers, mounted on tripod stands, are not fitted directly to the lateral pipelines but are connected to them via flexible hoses. The hoses and sprinklers can be moved laterally on either side to cover a number of lateral positions (2).
Assessment of Pollution Outflow from Large Agricultural Areas
Authors: Jha Ramakar , Bhatia K.K.S. , OJHA C.S.P.
Published: April 2005

The pollution from large agricultural areas in general is discussed. The potential of remote sensing and geographical information system as input for NPS pollution assessment is emphasized. Mathematical models commonly used for assessing of nonpoint source (NPS) pollution are also described. Assessment of nutrient pollution from three agricultural watersheds of a typical Indian river basin ranging from 2–5 km
2
is considered as an illustrative example.