bluuebunny/crossref_metadata_2025 huggingface dataset:
The prevalence, diagnosis, and management of voice disorders in a National Ambulatory Medical Care Survey (NAMCS) cohort
Authors: Best Simon R. , Fakhry Carole
Published: September 2010

Objectives:

The purpose of this study was to analyze the prevalence, presentation, and treatment of voice complaints (VC) using a national cohort of ambulatory care patients and describe how this care conforms to guidelines for the treatment of vocal disorders.

Methods:

Cross‐sectional study of 2005–2007 National Ambulatory Medical Care Survey (NAMCS) database.

Results:

Of 87,835 outpatient encounters, 0.26% and 3.2% of total and otolaryngology visits, respectively, were for VC. Patients with a VC were more likely to be female, have a history of asthma and tobacco use, present with acute symptoms, and have been referred to a specialist than those without VC. As recommended in national guidelines, the most common diagnostic procedure was endoscopic laryngoscopy (22%) with few other diagnostic imaging modalities performed (8%). Laryngeal diagnoses were more common than infectious or gastrointestinal diagnoses and were more likely to be chronic in presentation and associated with a diagnostic laryngoscopy evaluation (P = .02, <.001). They were not associated with gender, age, or tobacco use (P = .51, .35, .07). The most common intervention was antireflux medication (27%), with 13% receiving antibiotics, usually from primary care physicians. Only 8% were referred for voice therapy, despite strong national recommendations to consider this intervention for those with voice disorders.

Conclusions:

The current study demonstrates that nationally a significant proportion of diagnostic and treatment plans for patients with VC are consistent with published guidelines. However, physicians from all specialties should be aware of these guidelines to improve care for patients with voice disorders. Laryngoscope, 2011
Local response to chemoradiation in T4 larynx cancer with cartilage invasion
Authors: Patel Urjeet A. , Howell Lori K.
Published: September 2010

Background:

Patients with cartilage invasion were excluded from organ preservation protocols treating laryngeal and hypopharyngeal cancer. Treatment choice between chemoradiotherapy (CRT) and total laryngectomy (TL) remains controversial for these patients.

Objective:

To assess local response and local recurrence after CRT for patients having T4 larynx or hypopharynx cancer with cartilage invasion.

Design:

Retrospective intervention study.

Setting:

Tertiary‐care, urban public hospital.

Patients:

Patients with T4 squamous cell carcinoma of the larynx/hypopharynx with cartilage invasion treated from 2003 to 2009.

Intervention:

Curative‐intent CRT, compared to TL.

Outcome Measures:

Local response and local recurrence.

Results:

Of 34 patients included in this study, 21 completed CRT and 13 underwent TL with postoperative RT or CRT. With CRT, 19 patients were noted to have a complete response at the primary site while two patients had persistent local disease. Of 19 patients with complete response, 4 developed local recurrence over a time period 76–226 days (mean: 177 days). This resulted in a 29% incidence of persistent/recurrent disease at the primary site. The remaining 15 patients (71%) remained free of local disease (mean follow‐up: 369 days). For 13 patients undergoing TL with adjuvant therapy, there were no cases of local recurrence (mean follow‐up: 389 days).

Conclusions:

Although there was a high initial complete response rate after CRT, this response was not durable with a high local recurrence rate within 1 year. In comparison, patients undergoing TL demonstrated markedly better local control. For patients with cartilage invasion, a prospective trial comparing medical versus surgical therapy is needed. Laryngoscope, 2011
Thyroid storm in a patient with fulminant hepatic failure
Authors: Kandil Emad , Khalek Mohamed Abdel , Thethi Tina , Abd Elmageed Zakaria , Khan Amna , Jaffe Bernard M.
Published: September 2010

This manuscript describes a 28‐year‐old patient with a history of Graves' disease who was transferred to Tulane University Hospital with fulminant hepatic failure. He reported associated nausea, vomiting, anorexia, as well as jaundice and abdominal discomfort for a period of 3 weeks prior to his admission. His thyroid function tests on admission were TSH, 0.013 μU/mL; T3, 94.9 μU/mL; T4, 9.37 μU/mL; Free T4, >6 μU/mL. His liver function tests were characteristic of hepatic failure. The patient underwent an emergent liver transplant. His surgery was complicated by heart failure and acute respiratory distress syndrome. Given the patients clinical presentation and laboratory results, a diagnosis of thyroid storm was made and a decision was made to proceed with an emergent thyroidectomy. The posttransplant multiorgan dysfunction was rapidly reversed by prompt thyroidectomy and decisive management. The patient was discharged from the hospital with normal thyroid and liver function tests. Laryngoscope, 2011
Characteristics of vestibular evoked myogenic potentials in children with enlarged vestibular aqueduct
Authors: Zhou Guangwei , Gopen Quinton
Published: September 2010

Objective/Hypothesis:

To explore the characteristics of vestibular evoked myogenic potential (VEMP) in children with enlarged vestibular aqueduct (EVA) and to determine the diagnostic value of VEMP testing for this particular inner ear structural anomaly.

Study Design:

Retrospective cohort study in a pediatric tertiary care facility.

Methods:

A total of 25 pediatric cases (37 ears) of EVA were identified with complete records, including otologic evaluation, CT scan of the temporal bone, and audiologic assessment. Results of audiometry, tympanometry, and VEMP testing were analyzed.

Results:

Hearing loss was found in 97% (36/37) of the ears with EVA. Airbone gaps (conductive components) were found in all hearing losses with normal middle ear pressure and mobility. Abnormally low threshold VEMP responses were found in 92% (34/37) of the ears with EVA. VEMP responses were absent unilaterally in three EVA patients who had vestibular complaints. No clear correlation was found between the size of EVA and the audiologic findings.

Conclusions:

The presence of airbone gaps in children with EVA was found without apparent middle ear pathology. Characteristics of VEMP in EVA were lower thresholds and higher amplitudes despite of the presence of airbone gaps. The abnormally low threshold VEMP responses suggested a “third” window effect in the pathologic condition of EVA. Unilateral absence of VEMP may implicate peripheral vestibular impairment. The findings from our study are helpful in clinical evaluation of young children who usually give limited and ambiguous input regarding their hearing and vestibular problems. Laryngoscope, 2011
Prospective, randomized controlled assessment of the short‐ and long‐term efficacy of a hearing conservation education program in Canadian elementary school children
Authors: Neufeld Anastasia , Westerberg Brian D. , Nabi Shahin , Bryce Graham , Bureau Yves
Published: September 2010

Objective:

To assess the efficacy of a hearing conservation program in changing acoustic risk‐taking and hearing conservation behaviors in elementary school children.

Study Design:

Prospective, randomized, mixed design controlled study.

Methods:

Participants were grade‐six students from 16 Vancouver School Board schools. Differences between the intervention and control group responses on a behavioral questionnaire were measured at baseline, and then at 2 weeks and 6 months after administration of a hearing conservation program (Sound Sense™).

Results:

The intervention resulted in significant interactions for improved earplug use at dances (P = .019), rock concerts (P = .001), with percussion musical instruments (P = .002), and electric guitars (P = .028) at 2 weeks postintervention relative to baseline. Improvements in children's earplug use at dances (P = .041), rock concerts (P = .0024), and with power lawn mowers (P = .043) at 6 months postintervention relative to baseline were also observed. Behavior in the intervention group compared to control group improved in earplug use with any “other noises” at 2 weeks (P = .001), and 6 months (P = .022) relative to baseline. There was a tendency in the intervention group to reduce the duration of use of personal music devices at 2 weeks and 6 months after the hearing conservation program, which was nonsignificant.

Conclusion:

The Sound Sense™ hearing conservation program improved earplug use practices in elementary school children in the short and long term. The development, implementation and evaluation of a community‐based health promotion project around hearing loss can serve as a tremendous opportunity for students to develop their knowledge and skills in health advocacy. Laryngoscope, 2011
The increased risk of community‐acquired methicillin‐resistant Staphylococcus aureus neck abscesses in young children
Authors: Duggal Praveen , Naseri Iman , Sobol Steven E.
Published: September 2010

Objectives/Hypothesis:

To analyze the microbiological origins of deep neck space infections requiring surgical intervention in a pediatric population.

Study Design:

Retrospective cohort study.

Methods:

The study population (N = 136) included all pediatric patients surgically treated for deep neck space abscesses in a metropolitan tertiary care children's hospital over the course of 5 years (September 2004–August 2009). Demographic and clinical information was compared with microbiological isolate data.

Results:

Microbiological analysis of 118 bacterial isolates demonstrated 49 (42%) methicillin‐resistant Staphylococcus aureus (MRSA), 35 (30%) methicillin‐sensitive S. aureus, and 34 (28%) non‐S. aureus (N‐SA) isolates. The median age was 16 months (range, 1 month–13years). Patients <16 months of age were 10 times more likely to have an S. aureus (SA) infection versus N‐SA (P <.0001). MRSA comprised the majority of all SA isolates (58%). Eighty percent of all SA abscesses were located in the lateral neck. African American pediatric patients accounted for 70% of all deep neck space infections, and 86% of all MRSA infections. Clindamycin resistance was noted in 8% (4/49) of all community‐acquired MRSA isolates.

Conclusions:

Children younger than 16 months and/or with lateral neck abscesses are at a significantly increased risk of having an SA infection, the majority being MRSA. Laryngoscope, 2011
Stabilization procedures in coupled poromechanics problems: A critical assessment
Authors: Preisig Matthias , Prévost Jean H.
Published: September 2010

Numerical solutions for problems in coupled poromechanics suffer from spurious pressure oscillations when small time increments are used. This has prompted many researchers to develop methods to overcome these oscillations. In this paper, we present an overview of the methods that in our view are most promising. In particular we investigate several stabilized procedures, namely the fluid pressure Laplacian stabilization (FPL), a stabilization that uses bubble functions to resolve the fine‐scale solution within elements, and a method derived by using finite increment calculus (FIC). On a simple one‐dimensional test problem, we investigate stability of the three methods and show that the approach using bubble functions does not remove oscillations for all time step sizes. On the other hand, the analysis reveals that FIC stabilizes the pressure for all time step sizes, and it leads to a definition of the stabilization parameter in the case of the FPL‐stabilization. Numerical tests in one and two dimensions on 4‐noded bilinear and linear triangular elements confirm the effectiveness of both the FPL‐ and the FIC‐stabilizations schemes for linear and nonlinear problems. Copyright © 2010 John Wiley & Sons, Ltd.
Preparation and orientation behavior of multi‐walled carbon nanotubes grafted with a side‐chain azobenzene liquid crystalline polymer
Authors: Hu Tianhui , Xie Helou , Chen Li , Zhong Guanqun , Zhang Hailiang
Published: September 2010

Covalent functionalization of multi‐walled carbon nanotubes (MWNTs) with side‐chain azobenzene liquid crystalline poly{6‐[4‐(4‐methoxyphenylazo)phenoxy]hexyl methacrylate} (PMMAZO) was successfully achieved via atom transfer radical polymerization. The resultant samples were characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis and transmission electron microscopy. The results of differential scanning calorimetry and polarized optical microscopy show that the liquid crystalline behavior of PMMAZO‐functionalized carbon nanotubes (CNT‐PMMAZO) is similar to that of the PMMAZO homopolymer. The orientation of MWNTs and CNT‐PMMAZO in a PMMAZO matrix in the presence of an electric field was investigated. The results indicate that the orientation of MWNTs is dominated by the viscosity of the matrix, but the orientation of CNT‐PMMAZO is controlled by both the viscosity and the presence of a liquid crystalline phase ascribed to the compatibility between MWNTs and PMMAZO becoming better after covalent modification. Copyright © 2010 Society of Chemical Industry
Molecular characterization of the endoplasmic reticulum: Insights from proteomic studies
Authors: Chen Xuequn , Karnovsky Alla , Sans Maria Dolors , Andrews Philip C. , Williams John A.
Published: September 2010

The endoplasmic reticulum (ER) is a multifunctional intracellular organelle responsible for the synthesis, processing and trafficking of a wide variety of proteins essential for cell growth and survival. Therefore, comprehensive characterization of the ER proteome is of great importance to the understanding of its functions and has been actively pursued in the past decade by scientists in the proteomics field. This review summarizes major proteomic studies published in the past decade that focused on the ER proteome. We evaluate the data sets obtained from two different organs, liver and pancreas each of which contains a primary cell type (hepatocyte and acinar cell) with specialized functions. We also discuss how the nature of the proteins uncovered is related to the methods of organelle purification, organelle purity and the techniques used for protein separation prior to MS. In addition, this review also puts emphasis on the biological insights gained from these studies regarding the molecular functions of the ER including protein synthesis and translocation, protein folding and quality control, ER‐associated degradation and ER stress, ER export and membrane trafficking, calcium homeostasis and detoxification and drug metabolism.
Mastering Complexity and Changes in Projects, Economy, and Society via Project Management Second Order (PM-2)
Authors: Saynisch Manfred
Published: September 2010

Project Management Second Order (PM-2) is based on new insights in modern natural and social sciences, which were analyzed in a research program. This was explained in a previously published article in this journal (Saynisch, 2010). PM-2 is a new paradigm and will be the leading concept for the next decades. The concept of PM-2 was awarded the IPMA Research Award 2007 and the International Centre for Complex Project Management Research Prize 2010. The model represents a reference model. This article will explain the genesis of PM-2 as well as the principles, methods, and processes. Further, practical use will be discussed and real examples of transfer will be shown as well as PM-2 in the context of project-oriented companies. Integration aspects of CPMCS (ICCPM), ICB3 (IPMA), PMBOK® Guide/OPM3® (PMI) as a future view will be shown.
Fracture toughness and fracture mechanism of liquid‐crystalline epoxy resins with different polydomain structures
Authors: Harada Miyuki , Okamoto Naoki , Ochi Mitsukazu
Published: September 2010

Liquid‐crystalline (LC) epoxy resins were cured at different temperatures to obtain polydomain LC phase–cured resins. The cured resins had polydomain structures with a nematic LC phase and their domain diameters differed depending on the curing temperatures. The relationship between the domain diameter and fracture toughness of the diglycidyl ether of terephthalylidene‐bis‐(4‐amino‐3‐methylphenol) (DGETAM)/m‐phenylenediamine (m‐PDA) systems with the nematic phase and the previously reported smectic LC phase structures was investigated. It was clarified that the highly ordered LC structure (smectic phase) in each domain could improve the fracture toughness. In addition, the changes in the network orientation of the DGETAM/m‐PDA systems were evaluated by a mapping of the microscopic infrared dichroism in the fracture process and their toughening mechanism was suggested. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2010
Cell type dependence of carbon based nanomaterial toxicity
Authors: Horváth Lenke , Magrez Arnaud , Forró László , Schwaller Beat
Published: September 2010

Recent advances in nanotechnology led to the development of various nanostructures especially that of carbon‐based nanomaterials (CBNs) for industrial and biomedical uses. As a result, the production as well as the human exposure to these materials will increase in the future. Thus, it is primordial to also know the associated health hazards. We performed in vitro cell viability studies on different types of cultured cells exposed to multiwalled carbon nanotubes and carbon nanoparticles. Our work indicates that the tested materials are toxic and that the effects of materials are cell type dependent. Light microscopic observations of the cells when exposed to the highest dose of nanomaterials showed morphological alterations, which are characteristic for cell death, and were most pronounced in the case of macrophage cells. Further experiments are aimed at elucidating the mechanisms of toxicity of CBNs.
Effect of Leonurus cardiaca oil extract in patients with arterial hypertension accompanied by anxiety and sleep disorders
Authors: Shikov Alexander N. , Pozharitskaya Olga N. , Makarov Valery G. , Demchenko Dmitry V. , Shikh Evgenia V.
Published: September 2010

Leonurus cardiaca L. (Lamiaceae) is used traditionally for its sedative, hypotensive and cardiotonic effects. Due to the lack of clinical data regarding its effect in patients, a study was carried out to assess the clinical efficacy of Leonurus oil extract (LOE) in patients with arterial hypertension stages 1 and 2, accompanied by anxiety and sleep disorders.

Fifty patients were treated for 28 days with 1200 mg LOE per day. Positive effects of LOE on psycho‐emotional status and arterial blood pressure in patients with stage 1 hypertension were observed 1 week earlier than in patients with stage 2 hypertension. According to the Clinical Global Impression (CGI) scale, a significant improvement in the symptoms of anxiety and depression was observed in 32% of patients, a moderate improvement in 48% and a weak effect in 8%; 12% of patients did not respond to therapy. Side effects were minimal in all groups.

Leonurus oil extract may therefore be a potentially effective therapeutic agent for patients with arterial hypertension and concurrent psycho‐neurological disorders. Copyright © 2010 John Wiley & Sons, Ltd.
1,2‐Bis(halomagnesio)ethane
Authors: van Eikema Hommes N. J. R. , Bickelhaupt F. , Klumpp G. W.
Published: September 2010

1,2‐Bis(halomagnesio)ethane 3 is generated from diiodomethane and lithium‐4,4′‐di‐tert‐butylbiphenyl in the presence of MgBr2.
Synthesis of a SLex mimic: A potential E‐selectin binding antagonist
Authors: Heskamp B. M. , Veeneman G. H. , van der Marel G. A. , van Boeckel C. A. A. , van Boom J. H.
Published: September 2010

Iodonium‐ion‐assisted condensation of methyl 4,7,8,9‐tetra‐O‐acetyl‐N‐acetyl‐2‐O‐[3‐ (methylthiomethoxy)propyl]‐α‐D‐neuraminate (15) with hexyl 2‐acetamido‐6‐O‐benzyl‐3‐O‐(tri‐O‐ benzyl‐α‐L‐fucopyranosyl)‐2‐deoxy‐β‐D‐glucopyranoside (12) furnished, after deprotection, SLex mimic 3. The non‐fucosylated derivative 2 was obtained in a similar fashion by the coupling of 15 with hexyl 2‐acetamido‐3‐O‐benzoyl‐6‐O‐benzyl‐2‐deoxy‐β‐D‐glucopyranoside (8).
Synthesis, X‐ray structure, spectroscopic and cation complexation studies of macrocyclic ligands incorporating the 9,9′‐(ethane‐1,2‐diyl)bis(anthracene) photoactive subunit
Authors: Desvergne J.‐P. , Lauret J. , Bouas‐Laurent H. , Marsau P. , Lahrahar N. , Andrianatoandro H. , Cotrait M.
Published: September 2010

Two 9,9′‐(ethane‐1,2‐diyl)bis(anthracene) ligands, incorporating an ethano bridge, namely the bis‐anthracene coronand 1 and the bis‐anthracene cryptand 2, respectively, have been studied in parallel to compare their binding abilities, spectroscopic and photochemical properties in the presence and absence of cations as a function of their X‐ray structure. The ethano bridge imposes a twisted shape (torsion angles between the vicinal C‐H being 47° for 1 and 62° for 2a and 47° for 2b, the two conformers of compound 2), which inhibits the cation‐binding ability of 1 and attenuates that of cryptand 2 (log Ks ≈︁ 1.8 for Na+ or K+, ≈︁ 4 for Tl+ and ≈︁ 8 for Ag+); in CH3OH, both 1 and 2 emit essentially excimer‐type fluorescence at λmax 520‐535 nm, which is red‐shifted compared with that of the single crystals ( ≈︁ 465‐480 nm) where the rotation about the CH2‐CH2 bond is hindered. The presence of cations, which has no influence on the photocycloisomerization quantum yield of 1 (as expected), clearly affects that of 2. Cryptand 2 was shown to display photochromic properties.
New intrinsic fluoroionophores with dual fluorescence: DMABN‐Crown4 and DMABN‐Crown5
Authors: Létard J.‐F. , Delmond S. , Lapouyade R. , Braun D. , Rettig W. , Kreissler M.
Published: September 2010

Two new intrinsic fluoroionophores, with the electronic structure of 4‐(dimethylamino)‐ benzonitrile (DMABN): 4‐(1‐aza‐4,7,10‐trioxaclyclododecyl)benzonitrile (DMABN‐Crown4) and 4‐(1‐aza‐4,7,10,13‐tetraoxacyclopentadecyl) benzonitrile (DMABN‐Crown5) were synthesized and their absorption, fluorescence spectra and quantum yields of fluorescence measured and discussed. Comparison of X‐ray data and calculations from the density functional theory (DFT) shows that from DMABN to DMABN‐Crown5 the twist angle of the amino group with respect to the phenyl plane increases while the pyramidalization of the nitrogen is not significantly affected. The activation energies (Ea 8.9 kJ · mol−1, Ed 23.7 kJ · mol−1) and the enthalpy (ΔH‐14.8 kJ · mol−1) involved between the LE and TICT states of DMABN‐Crown5 were obtained in toluene and compared with those previously published for DMABN. The greater relief of strain (larger ΔH) which accompanies the formation of the TICT state in the crown derivatives, accounts for the higher proportion of TICT emission recorded at room temperature. The fluorescence of DMABN‐Crown5 in acetonitrile, is altered significantly at 3 · 10−4 mol · 1−1 of Ca2+: the long‐wavelength emission from the TICT state decreases while the short‐wavelength emission increases. From the wholly complexed probes, the two emissions are blue‐shifted relative to those of the free probe and originate from contact‐ and/or solvent‐separated probe‐cation pair with the probe in the LE and in the TICT state. Similarly, the fluorescence spectrum of DMABN‐Crown4, in acetonitrile, is altered significantly when Mg(CIO4)2 is added in concentrations of 5 · 10−3 mol · 10−1 or above.
Some aspects of the role of amines in the photoinitiated polymerisation of acrylates in the presence and absence of oxygen
Authors: Bradley Grant , Davidson R. Stephen
Published: September 2010

Triethanolamine (1), N‐methyldiethanolamine (2) and N,N‐dimethylethanolamine (3) have been used in conjunction with the 2‐(2‐chlorophenyl)‐4,5‐diphenylimidazolyl radical and triplet benzophenone to initiate the polymerisation of lauryl acrylate. The radical abstracts a hydrogen atom from the amine to generate an α‐aminoalkyl radical. From the order of reactivity of the amines towards the lophyl (triarylimidazolyl) radical i.e. 2 >> 1 > 3 it is concluded that hydrogen‐atom abstraction occurs rather than electron followed by proton transfer. The imidazolyl radicals abstract hydrogen from thiols in a similar fashion more effectively to give thiyl radicals which initiate polymerisation of the acrylate. By following the progress of the polymerisation reactions by RTIR spectroscopy, it was concluded that the effectiveness of the amines to reduce oxygen inhibition is 1 < 3 < 2. The ability of the amines to act as synergists in the polymerisation of thin films of lauryl acrylate initiated by lophyl radicals and triplet benzophenone was assessed. The efficiency of the amines was found to be 2 ∼ 1 > 3 for reaction with lophyl radicals whereas with triplet benzophenone the three amines gave similar amounts of polymer. For amines 2 and 3, two types of amino alkyl radical can be generated. It is concluded that radicals of type > NCHCH2OH are more effective initiators than CH2N <.
Synthesis of (R)‐ and (S)‐2‐hydroxy‐3‐enoic acid esters
Authors: Warmerdam E. G. J. C. , van den Nieuwendijk A. M. C. H. , Brussee J. , van der Gen A. , Kruse C. G.
Published: September 2010

The synthesis of (R)‐ and (S)‐2‐hydroxy‐3‐enoic acid esters [(R)‐1a‐d and (S)‐1a‐c] is described. The (R) enantiomers were prepared by a Pinner synthesis from the corresponding (R)‐cyanohydrins [(R)‐2a‐d], which in turn were obtained by R‐oxynitrilase‐ (E.C. 4.1.2.10)‐catalyzed addition of HCN to the α,β‐unsaturated aldehydes 3a‐d. For the preparation of the (S) enantiomers an inversion of the configuration had to be implemented. A critical evaluation of the two possible sequences: inversion of the configuration of the cyanohydrins followed by solvolysis of the nitrile function, and solvolysis of the cyanohydrins followed by inversion of the configuration of the resulting α‐hydroxy esters, came out in favor of the latter pathway.
Synthesis of pyridopyrazino[2,3‐b]indoles and 10H‐indolo[3,2‐g]pteridins
Authors: Bergman Jan , Vallberg Hans , Damberg Charlotta
Published: September 2010

The reactions between isatin (8a) and N‐acetylisatin (8b) with pyridine‐2,3‐diamine (9a), pyridine‐3,4‐diamine (9b) and pyrimidine‐4,5‐diamine (21) were studied. 10H‐Pyrido[3′,2′:5,6]pyrazino[2,3‐b]indole (5a), 6H‐pyrido[2′,3′:5,6]‐pyrazino[2,3‐b]indole (5b), 6H‐pyrido[3′,4′:5,6]pyrazino[2,3‐b]indole (5c) and 10H‐pyrido[4′,3′:5,6]pyrazino[2,3‐b]indole (5d) were regioselectively synthesized in a three‐step synthesis from N‐acetylisatin and the appropriate pyridine diamine. The structures of the intermediates were assigned by NOESY experiments. In the same manner, 10H‐indolo[3,2‐g]pteridine (24) was synthesized from N‐acetylisatin and pyrimidine‐4,5‐diamine.
The effects of chain flexibility on the properties of vesicles formed from di‐n‐alkyl phosphates
Authors: Smits Elly , Engberts Jan B. F. N. , Blandamer Michael J. , Briggs Barbara , Cullis Paul M.
Published: September 2010

This paper describes a study of the effects of chain flexibility and chain packing on the properties of vesicles formed from sodium di‐n‐alkyl phosphates. Three di‐n‐alkyl phosphates with a constant chain length but with different degrees of unsaturation have been synthesized: dioleyl phosphate (DOP) and dielaidyl phosphate (DEP) having, respectively, a cis and a trans double bond at C‐9 and the saturated distearyl phosphate (DSP). These surfactants form vesicles, as confirmed by transmission electron microscopy (EM). The gel to liquid‐crystalline phase transition was studied using both fluorescence polarization and differential scanning microcalorimetry. According to fluorescence polarization, using trans, trans, trans‐1,6‐diphenyl‐hexa‐1,3,5‐triene (DPH) as a probe, DSP vesicles undergo a cooperative transition from a gel to a liquid‐crystalline state at 72°C. The polarization of the probe captured in DOP or DEP vesicles decreased gradually in the temperature range 0–40°C, indicating a non‐cooperative phase transition. It appears that the vesicle bilayer is in a gel state below 0°C and in a liquid‐crystalline state above 40°C. A temperature‐dependent 31P NMR study failed to identify the exact phase‐transition temperature. The effect of the fusogenic cation Ca2+ was studied qualitatively using EM. Calcium induces fusion of DEP vesicles but, within a short time, tubules are formed which are most probably anhydrous crystals of the calcium salts. For DSP vesicles the latter process is extremely fast and fused vesicles cannot be detected. In contrast, DOP vesicles fuse under the influence of calcium, but no crystallization takes place. The fused DOP vesicles are stable for more than one week in the presence of 4 mM Ca2+ stored at room temperature or at 60°C. Addition of EDTA to DOP vesicles leads to chelation of the calcium ions and to a transition to multilamellar vesicles.
Synthesis of carba‐β‐DL‐fucose and carba‐β‐DL‐galactose from myo‐inositol
Authors: Verduyn R. , van Leeuwen S. H. , van der Marel G. A. , van Boom J. H.
Published: September 2010

Cyclic ketone 12, prepared from racemic 3‐O‐benzyl‐1,2:4,5‐di‐O‐cyclohexylidene‐myo‐inositol (4), was converted into the tertiary alcohols 13 and 20 by treatment with methyl‐magnesium bromide and (benzyloxymethyl)lithium, respectively. Deoxygenation, followed by hydrogenolysis of the benzyl protective groups, furnished the title compounds 2 and 3.
Synthesis and properties of a fluorescent nucleotide derivative
Authors: Petra D. G. I. , de Boer R. F. , Koomen G. J. , Meeuwenoord N. J. , Kuyl‐Yeheskiely E. , van der Marel G. A. , van Boom J. H.
Published: September 2010

Strong fluorescent deoxyadenosine derivatives are of considerable research importance in cell biology. We prepared the deoxyriboside of methyl 3,7‐dihydro‐7‐oxo‐[2,1‐i]pyrimidopurine‐9‐carboxylate (compound 1b, deoxyribofuranosyl A*)1 which was subsequently used in the synthesis of the dimer d(A*T).
New bioactive organic compounds from turkish medicinal plants
Authors: ŞLener Bilge , Atta‐Ur‐Rahman Atta‐Ur‐Rahman
Published: September 2010

Turkey has a very rich flora and a long history of herbal medicine practices. The biological evaluation of substances from plant sources is highly relevant for the identification of lead compounds which can result in the development of novel and safe medicinal agents. During our extensive studies with Turkish medicinal plants, we have isolated and characterized a large number of natural products. Although Turkey is endowed with a wide variety of medicinal plants, very little effort has been made so far towards bioassay‐directed isolation of biologically active compounds from indigenous plants. During the past few years, we have also been engaged in the isolation and structure elucidation of compounds through a bioassay‐directed fractionation procedure.

In this manuscript, new bioactive steroidal alkaloids isolated from Buxus, Veratrum and Fritillaria species are presented. Among these, four steroidal alkaloids isolated from the leaves of Buxus longifolia have shown significant antibacterial activity against Salmonella typhi, Shigella flexneri, Escherichia coli and Pseudomonas aeruginosa. Three steroidal alkaloids from Veratrum album have been shown to have antihypertensive actions. In addition, a new steroidal base obtained from the bulbs of Fritillaria imperialis exhibited anticholinergic activity as manifested by the blockade of acetylcholine responses on isolated guinea‐pig ileum and atria.
Virtually no environmental impact: The biphasic oxo process
Authors: Cornils Boy , Wiebus Ernst
Published: September 2010

Water‐soluble catalysts offer significant advances in homogeneous catalysis: the “heterogenization” of the catalyst in a second, immiscible liquid phase immobilises the catalyst phase, thus combining the advantages of heterogeneous catalysis, e.g. long lifetime, easy separation of product from catalyst, with those of the homogeneous type, namely, defined species of catalyst, gentle reaction conditions, high activity and selectivity.

The first successful large‐scale application of aqueous catalysts is the oxo process of Ruhrchemie/Rhône‐Poulenc, using a HRh(CO)[P‐(3‐sulfophenyl‐Na)3]3 catalyst, dissolved in water. This survey reviews 10 years' experience of this process against the background of biphasic catalyses, especially the way in which this environmental benign technique, which is highly economic and thus very environmentally sound, reduces pollution.
Oxidation of glucose and gluconate on Pt, Pt Bi, and Pt Au catalysts
Authors: Besson M. , Flèche G. , Fuertes P. , Gallezot P. , Lahmer F.
Published: September 2010

Glucose and gluconate aqueous solutions (2 mol/l) were oxidized with air (atmospheric pressure, 333K, pH 7) on active charcoal‐supported, platinum catalysts (catalytic ratios substrate/Pt ≥ 787); some catalysts were promoted with bismuth or gold. The activity of unpromoted Pt/C catalysts for glucose oxidation was comparable with that of Pd‐Bi/C catalysts and there was no deactivation; gluconate formed transiently was oxidized into glucarate, the final selectivity did not exceed 50%. The oxidation of gluconate on very well dispersed Pt catalysts prepared by cationic exchange or anionic adsorption leads to higher glucarate selectivities than those previously reported, in spite of the fact that the present solutions were much more concentrated and reduced amounts of platinum were used. Addition of bismuth adatoms by surface redox reaction produces a shift in selectivity towards 2‐ketogluconate. Addition of gold adatoms on platinum decreases the catalyst deactivation.
Catalyzed oxidation of 2‐mercaptobenzothiazole to 2‐hydroxybenzothiazole
Authors: Stolcova Magdalena , Hronec Milan
Published: September 2010

The selective oxidation of 2‐mercaptobenzothiazole to 2‐hydroxybenzothiazole with molecular oxygen at temperatures of 50‐150°C and pressures of 0.3‐0.7 MPa has been studied in the presence of transition metal catalysts. The reaction proceeds via corresponding sulfinic and sulfonic acids which are quickly decomposed to the desired product in acetic acid as solvent at the reaction temperature. At temperatures below 90°C, the main reaction product is 2,2′‐dithiobis(benzothiazole) which is resistant to further oxidation. The type of central atom and ligand of the metal catalyst has a strong influence on the selectivity of 2‐hydroxybenzothiazole formation. In the presence of FeCl2 as catalyst, 85% selectivity at 95% conversion was achieved.
Environmentally friendly synthesis of coumarin derivatives employing heterogeneous catalysis
Authors: Gunnewegh E.A. , Hoefnagel A.J. , Downing R.S. , van Bekkum H.
Published: September 2010

Zeolite H‐BEA and other solid acids have been shown to be effective catalysts for the production of coumarin derivatives from activated phenols and acids or esters possessing an additional alkylation function, or β‐keto esters (Pechmann reaction). These heterogeneous catalysts eliminate the production of acidic waste streams associated with conventional (Lewis) acid catalysts. Zeolite H‐BEA proved to be the preferred catalyst.
Alcohol‐dehydrogenase‐catalyzed production of chiral hydrophobic alcohols. A new approach leading to a nearly waste‐free process
Authors: Kruse Wolfgang , Hummel Werner , Kragl Udo
Published: September 2010

The enantioselective enzyme‐catalyzed reduction of ketones in an enzyme membrane reactor coupled to a membrane‐based extractive product separation was developed for the production of chiral hydrophobic alcohols. Enantiomerically pure (S)‐1‐phenylpropan‐2‐ol, (S)‐4‐phenylbutan‐2‐ol and (S)‐6‐methylhept‐5‐en‐2‐ol (sulcatol) were obtained with high purities.

In spite of low substrate concentrations (9‐12 mM) space‐time yields higher than 100 g/(l·d) and concentrated product solutions were obtained.

Formate‐dehydrogenase‐catalyzed regeneration of cofactor, together with process‐integrated recycling of cofactor, led to total‐turnover numbers for NAD+ of up to 1350 molP/molNAD, which means a 25‐fold increase in comparison with standard techniques without cofactor retention.

Because of the closed‐loop design of the reactor the process can be run almost without waste, yielding the pure chiral alcohol and CO2.
Alternating copolymerization of alkenes and carbon monoxide catalyzed by cationic palladium complexes
Authors: Drent E. , van Broekhoven J.A.M. , Budzelaar P.H.M.
Published: September 2010

In the late 1940s,Reppediscovered a nickel catalyst for the co‐oligomerization of ethene and carbon monoxide. Since then, various groups have made attempts to develop more efficient catalysts for this reaction. The recent discovery of a new class of very active palladium catalysts now allows, for the first time, ready access to a large variety of high‐molecular‐weight alkene/carbon‐monoxide co‐ and terpolymers. The catalysts comprise acis‐coordinated palladium(II) species associated with weakly or non‐coordinating anions. Their discovery has made it possible to develop a viable process for the commercial production of the first members of the new family of CARILON‐olefin/carbon monoxide copolymers.

In this brief review, we highlight some key phenomena in polyketone catalysis. The elementary reaction steps in the palladium‐catalyzed polyketone formation during chain propagation, initiation and termination are outlined. The role of bidentate ligands and the reasons for perfect alternation in polymer chain growth are dicussed. The attractive feature of the catalysts, that they also catalyze the co‐ and terpolymerization of olefins higher than ethene with carbon monoxide, is briefly noted. A parallel between polyketone catalysis by cationic palladium complexes and modern polyolefin catalysis by cationic metallocene complexes is suggested.
Unprecedented observation of pronounced vibrational structure in charge‐transfer absorption and emission spectra
Authors: Wiering P.G. , Verhoeven J.W.
Published: September 2010

Two rigidly bridged electron donor‐acceptor systems are reported that display discrete, intramolecular charge‐transfer (CT) absorption and emission spectra in solution at room temperature. For both the CT‐absorption is highly structured irrespective of solvent, for one also the CT‐fluorescence in a nonpolar solvent is structured.
Synthesis and spectroscopic characterisation of 13C‐labelled anthranilic acid
Authors: van Liemt W.B.S. , van Henegouwen W. G. Beijersbergen , van Rijn A. , Lugtenburg J.
Published: September 2010

The three isotopomers (1–13C)‐, (2‐13C)‐, and (6‐13C)‐ anthranilic acid (2‐aminobenzoic acid) have been synthesised from simple 99% 13C‐labelled starting materials. The isotopomers have been characterised using mass spectrometry, 1H‐NMR spectroscopy and 13C‐NMR spectroscopy. The spectroscopic results confirm that, within experimental error, the syntheses were accomplished without scrambling or dilution of label. The labelled anthranilic acids are used as substrates for bioconversion into the correspondingly labelled L‐tryptophans. For this purpose, the (2‐13C)‐ label has been synthesised on the gram scale.
An efficient synthetic method for β‐cyclolavandulal and its corresponding alcohol
Authors: Oda Mitsunori , Isobe Atsushi , Hayashi Masashi , Miyatake Ryuta , Shimao Ichiro , Kuroda Shigeyasu
Published: September 2010

3,3‐Dimethylcyclohexanone (5) was efficiently converted to methyl β‐cyclolavandulate (6) in 74% yield in three steps, one of which included the preparation of β‐methyl α,β‐unsaturated esters by coupling lithium dimethylcuprate with enol phosphates of β‐oxo esters. Reduction of 6 with LiAlH4 gave β‐cyclolavandulol (2) in 94% yield and oxidation of 2 with pyridinium chlorochromate in the presence of molecular sieves afforded the title aldehyde quantitatively.
Synthesis of alkyl ethynyl tellurides and 1,2‐bis(alkyltelluro) acetylenes by electrophilic‐reagent‐induced reaction of dialkyl ditellurides with acetylene
Authors: Potapov V.A. , Amosova S.V. , Shestakova V.Y.U. , Zhnikin A.R. , Petrov B.V.
Published: September 2010

The reaction of dialkyl ditellurides with acetylene occurs only in the presence of an electrophilic reagent (alkyl halides, Lewis acid) to afford alkyl ethynyl tellurides and 1,2‐bis(alkyltelluro) acetylenes in up to 96% total yield.
A thermal rearrangement of ethylene acetal of bicyclo[4.2.0]octa‐4,7‐diene‐2,3‐dione
Authors: Oda Mitsunori , Kamata Yoshitaka , Nishii Satoshi , Miyatake Ryuta , Kuroda Shigeyasu , Oda Masaji
Published: September 2010

Pyrolysis of the title compound 3 at 400 °C gave α‐(2‐hydroxyphenyl)‐γ‐butyrolactone (4) whose structure was confirmed by an alternative synthesis. A reaction mechanism via a phenyl ketene acetal is proposed.
Surface reactions of ethylene with deuterium, oxygen and nitrogen oxide on rhodium: Kinetics and mechanism
Authors: Niemantsverdriet J.W. , Borg H.J. , van Hardeveld R.M. , van Santen R.A.
Published: September 2010

The kinetics of surface reactions of ethylene adsorbed on the (111) surface of a rhodium single crystal has been investigated by means of temperature‐programmed desorption and static secondary‐ion mass spectrometry (SSIMS). These reactions include the decomposition of ethylene to ethylidyne (CCH3), and the exchange of H for D‐atoms in the latter, the oxidation of adsorbed ethylene and its reaction with coadsorbed NO. The formation of relatively large amounts of HCN indicates that C‐N coupling on rhodium is possible under mild conditions.
Mechanistic study of the selective hydrogenolysis of CCI2F2 (CFC‐12) into CH2F2 (HFC‐32) over palladium on activated carbon
Authors: van de Sandt Emile J. A. X. , van Bekkum Herman , Wiersma André , Makkee Michiel , Moulijn Jacob A.
Published: September 2010

The influence of process parameters such as temperature (400‐560K), H2/CCl2F2 ratio (2.2‐20), and Weight Hourly Space Velocity (WHSV) (0.3‐1.0 g/(g · h)) on the hydrogenolysis of CCl2F2 into CH2F2 over palladium on activated carbon has been investigated. The reactivity of CHCIF2 and CH2F2 and the influence of HCl were also examined. In the reaction of CCl2F2, the main product is CH2F2. Significant amounts of CHCIF2 and CH4 are also found. The catalyst shows a remarkably high selectivity to CH2F2, in the range of 70‐90 mol%, at all conversion levels in a broad range of process conditions. A mechanism is proposed in which the reaction proceeds mainly via parallel reaction pathways. One route results in CH2F2 and CHCIF2, while the other route yields CH4. The selectivity to CH2F2 and CHCIF2 is determined by the amount of adsorbed chlorine on the catalytic surface and a constant selectivity for CH4 was found. High selectivity for CH2F2 can be achieved at high H2/CCl2F2 ratios and low HCl concentration. The postulated mechanism is supported by thermodynamic data.
Volcanoes and climate
Authors: Cole‐Dai Jihong
Published: September 2010

Of the natural forcings causing short‐term climatic variations, volcanism, along with its climatic impact, is perhaps the best understood. The primary net result of the impact is the reduced receipt of solar energy at Earth's surface due to the scattering of incoming solar radiation by secondary sulfate aerosols formed from volcanic sulfur. The quantitative effects can be measured in energy‐balance‐based climate models, which require validation using high‐quality paleoclimatic and paleovolcanic data. An important advancement in the effort to understand the role of volcanism in climate change in the recent decade is the significant improvement in paleovolcanic records from polar ice cores, represented by long records with unprecedented temporal accuracy and precision, and by the potential to identify climate‐impacting stratospheric eruptions in the records. Other improvements include (1) the investigation of long‐term relationship between eruptions (including super‐eruptions) and climate variations, beyond an eruption's radiative impact of up to a few years; (2) a better understanding of the response to volcanic perturbation of feedback mechanisms in the climate system; and (3) the limited role of volcanic eruptions in the era of human‐induced greenhouse warming. Urgent research/investigation is needed to evaluate the geoengineering proposition to counteract greenhouse warming by injecting sulfur dioxide into the stratosphere, which is based on the significant cooling effects of stratospheric volcanic eruptions, and its serious unintended consequences. WIREs Clim Change 2010 1 824–839 DOI: 10.1002/wcc.76

This article is categorized under:

Paleoclimates and Current Trends > Climate Forcing

Paleoclimates and Current Trends > Modern Climate Change

Paleoclimates and Current Trends > Paleoclimate
Climate hazards and disasters: the need for capacity building
Authors: McBean Gordon , Rodgers Caroline
Published: September 2010

Climate and climate‐related hazards such as floods, storms, and droughts have served as trigger events for more than 75% of the disasters that have occurred globally over the past decade. Proportionately, these disasters affect the least developed countries most intensely, proving to be especially harmful to poverty stricken populations. In the future, a changing climate is likely to exacerbate these effects and could make development unsustainable in many places. It is necessary to develop the capacity of all countries to combat hazards so that they do not become disasters. The international framework connects climate change and development, mainly within the UN Framework Convention on Climate Change. The Millennium Development Goals and Hyogo Framework for Action on Disaster Risk Reduction, and most recently the Declarations of the G8 and the Major Economies Forum on Energy and Climate provide further mandates for action. Climate hazards are now clearly linked with issues such as food security, migration, and national security. The linking of climate change adaptation and disaster risk reduction provides a framework for responding. The development of capacity for knowledge‐based reduction of hazards and disasters risk demands an integrated approach that recognizes the changing nature of natural hazards. Further, capacity development must also recognize the limitations in governmental response and facilitate alternate ways to overcome barriers. For example, the role of resilience is examined in order to demonstrate the tools available for policymakers and individuals, to respond to hazards as they occur. The path forward to sustainable development depends on investments in the development and then the utilization of knowledge‐based, integrated approaches that factor in the future in balance with the present needs of societies. WIREs Clim Change 2010 1 871–884 DOI: 10.1002/wcc.77

This article is categorized under:

Climate and Development > Sustainability and Human Well‐Being

Climate and Development > Social Justice and the Politics of Development
Pyrylium‐Synthesen 65 Jahre Pyryliumsalze
Authors: Schroth Werner , Fischer Gerhard , Balaban A. T.
Published: September 2010

Pyryliumsalze finden in den letzten Jahren ein steigendes theoretisches und präparatives Interesse. Es erscheint daher sinnvoll, im Rahmen einer Übersicht Synthesewege sowie sonstige präparative und reaktive Zusammenhange darzustellen.

Andere Übersichtsartikel betreffen vorwiegend die Reaktionen von Pyryliumsalzen und spezielle Synthesemöglichkeiten [12a], [77]. Über die von uns nur wahlweise und zu Vergleichszwecken angeführten Synthesen benzologer Pyryliumsalze (z. B. Chromylium‐ und Xanthyliumsalze) unterrichten bis zum Jahre 1951 ausführlich die Monographien in [12b].

Zweck einer solchen Gesamtschau soll es sein, weitere Arbeiten auf diesem experimentell wie theoretisch gleichermaßen wichtigen Teilgebiet der Heterocyclen‐Chemie anzuregen und die Einschätzung des bisher Erreichten zu erleichtern.
Neue Methoden zur Bestimmung von Leitfähigkeiten
Authors: Von Cruse K.
Published: September 2010

In Gegenüberstellung bisher bekannter Leitfähigkeitsmeßmethoden werden die prinzipiell anwendbaren Wege aufgezeigt, diskutiert und erörtert, die sich aus der Entwicklung der Meßtechnik ergeben. Soweit Meßergebnisse zu neuen Methoden vorliegen, wird auf deren Prinzip, auf deren Anwendungsmöglichkeiten und auf deren Vor‐ und Nachteile eingegangen. Neue Methoden mit Hochfrequenz werden dabei bevorzugt behandelt. Abschließend wird auf noch in Entwicklung begriffene neue Methoden hingewiesen.