bluuebunny/crossref_metadata_2025 huggingface dataset:
Respective importance of protein folding and glycosylation in the thermal stability of recombinant feruloyl esterase A
Authors: Benoit Isabelle , Asther Michèle , Sulzenbacher Gerlind , Record Eric , Marmuse Laurence , Parsiegla Goetz , Gimbert Isabelle , Asther Marcel , Bignon Christophe
Published: September 2006

The thermal stability of four molecular forms (native, refolded, glycosylated, non‐glycosylated) of feruloyl esterase A (FAEA) was studied. From the most to the least thermo‐resistant, the four molecular species ranked as follows: (i) glycosylated form produced native, (ii) non‐glycosylated form produced native, (iii) non‐glycosylated form produced as inclusion bodies and refolded, and (iv) glycosylated form produced native chemically denatured and then refolded. On the basis of these results and of crystal structure data, we discuss the respective importance of protein folding and glycosylation in the thermal stability of recombinant FAEA.
Depletion of Jab1 inhibits proliferation of pancreatic cancer cell lines
Authors: Fukumoto Akihisa , Tomoda Kiichiro , Yoneda-Kato Noriko , Nakajima Yoshiyuki , Kato Jun-ya
Published: September 2006

Jab1 overexpression is observed in many human cancers, but its physiological significance remains to be investigated. We reduced the level of Jab1 expression in pancreatic cancer cell lines, MIA PaCa‐2 and PANC‐1 by the RNA interference and found that Jab1‐knockdown resulted in impaired cell proliferation and enhanced apoptosis regardless of the genotype of the tumor suppressor p53. This growth inhibition was rescued by the introduction of siRNA‐resistant mouse Jab1 cDNA. Jab1‐knocked‐down cells expressed a higher level of c‐myc, and additional depletion of c‐myc rescued cells from Jab1‐knockdown‐mediated growth suppression. Thus, Jab1 overexpression contributes to pancreatic cancer cell proliferation and survival. Jab1 could be a novel target in cancer therapy.
Phosphorylation of Numb regulates its interaction with the clathrin‐associated adaptor AP‐2
Authors: Tokumitsu Hiroshi , Hatano Naoya , Yokokura Shigeyuki , Sueyoshi Yuka , Nozaki Naohito , Kobayashi Ryoji
Published: September 2006

Numb is thought to participate in clathrin‐dependent endocytosis by directly interacting with the clathrin‐associated adaptor complex AP‐2, although the underlying mechanisms are unknown. Numb is also known to be phosphorylated at Ser264 in vitro and in vivo. Here, we found that Numb is phosphorylated in vitro by Ca2+/calmodulin‐dependent protein kinase I on Ser283. This phosphorylation was also observed in transfected COS‐7 cells, indicating its physiological relevance. Pull‐down experiments showed that the phosphorylation of Numb impaired its binding to the AP‐2 complex and simultaneously recruited 14–3–3 proteins in vitro. Based on experiments using Numb mutants, both the initial phosphorylation of Ser264 and the subsequent phosphorylation of Ser283 are sufficient to abolish the binding of Numb to AP‐2 and to promote the interaction with 14–3–3 protein. These findings suggest a novel mechanism for the regulation of Numb‐mediated endocytosis, namely through direct phosphorylation.
Medical treatment of vulvar squamous cell hyperplasia
Authors: Ayhan A. , Guvendag Guven E.S. , Guven S. , Sakinci M. , Kucukali T.
Published: September 2006

Objective: To evaluate symptomatic response and recurrence rates of graduated topical fluorinated corticosteroid in patients with vulvar squamous cell hyperplasia.

Methods: Nine hundred seventy‐six patients with biopsy‐proven vulvar squamous cell hyperplasia from 1990 to 2003 were reviewed in this retrospective study. All patients were treated with graduated topical fluorinated corticosteroid. Data were obtained from hospital records. Symptomatic remission and recurrence rates were noted following six months local therapy.

Results: The mean age was 42.55 ± 10.93 (15‐85). The remission rate was 93.8% in six months. The remission rate was non‐significantly higher in postmenopausal patients than that in their premenopausal counterpart (94.9% vs 93.0%, p = 0.15). The disease recurred in 6.9% of patients. Of the patients that suffered recurrence 47.5% had persistent disease initially. The patients with following factors older ages (>40 years), postmenopausal period had significantly higher recurrence rates. Four patients with recurrent disease and six patients with persistent disease in the form of vulvar intraepithelial neoplasia I‐II or atypical squamous hyperplasia, were treated with skinning vulvectomy.

Conclusion: Corticosteroid in the treatment of vulvar squamous cell hyperplasia yielded excellent response rates. In the evaluation of patients without symptomatic relief, the first step should be a vulvar biopsy to exclude the presence of atypical components.
Natural History of Benign Paroxysmal Positional Vertigo and Efficacy of Epley and Lempert Maneuvers
Authors: Sekine Kazunori , Imai Takao , Sato Go , Ito Mahito , Takeda Noriaki
Published: September 2006

We assessed the efficacy of Epley maneuver in patients with posterior canal benign paroxysmal positional vertigo (P‐BPPV) and Lempert maneuver in patients with horizontal canal BPPV (H‐BPPV). In patients with P‐BPPV, positional vertigo in patients treated by Epley maneuver was significantly resolved more quickly than that in untreated patients. But in patients with H‐BPPV, there were no significant differences of time course in remission of positional vertigo between untreated patients and patients treated by Lempert maneuver. Among the untreated patients, the positional vertigo in patients with H‐BPPV was significantly resolved more quickly than that in patients with P‐BPPV. Epley maneuver was effective for the treatment of patients with P‐BPPV, whereas the efficacy of Lempert maneuver for the treatment of patients with H‐BPPV was limited. The natural courses in remission of positional vertigo in untreated patients with H‐BPPV showed significantly faster resolution than that in patients with P‐BPPV.
Balance Ability in Patients with Benign Paroxysmal Positional Vertigo
Authors: Chang Wen‐Ching , Hsu Li‐Chi , Yang Yea‐Ru , Wang Ray‐Yau
Published: September 2006

OBJECTIVE

The purpose of the study was to investigate the balance ability of the patients with benign paroxysmal positional vertigo (BPPV).

STUDY DESIGN AND SETTING

Twenty‐three patients (63.3 ± 9.2 years of age) with a diagnosis of unilateral posterior semicircular canal BPPV were recruited. Static balance was measured in 4 conditions with eyes open and eyes closed: stance on firm surface, stance on foam surface, left leg stance, and right leg stance. Dynamic balance was measured in tandem walk test. Data of the patients with BPPV were compared to age‐matched norm values of the healthy adults.

RESULTS

The patients with BPPV demonstrated greater sway velocity in stance on foam surface with eyes closed (P < 0.05), in single leg stance with eyes closed (P < 0.001), and in tandem walk test (P < 0.05) compared to the healthy adults.

CONCLUSIONS

Patients with BPPV demonstrated impaired static and dynamic balance ability particularly when depriving visual and changing proprioceptive inputs.

SIGNIFICANCE

Clinically, in addition to canalith repositioning maneuver, balance retraining on different conditions may be a useful adjunct to treatment for patients with BPPV.
Severity of Obstructive Sleep Apnea: Correlation with Clinical Examination and Patient Perception
Authors: Pang Kenny P. , Terris David J. , Podolsky Robert
Published: September 2006

OBJECTIVE

To correlate clinical history, patient self‐perception of obstructive sleep apnea, and physical examination with the severity of OSA.

METHODS

One hundred and two consecutive patients were prospectively enrolled over a 6‐month period. All patients underwent a comprehensive history and clinical examination, nasopharyngoscopy, and an overnight‐attended polysomnogram.

RESULTS

There were 65 males and 37 females with a mean age of 50.2 ± 11.3 years (range, 24 to 76 years). The mean apnea‐hypopnea index (AHI) was 37.9 ± 27.7 (range, 0.7 to 111.2). There was a strong correlation between patient self‐perception of OSA severity and AHI (r = 0.499, P < 0.0001), and the correlation with AI was 0.577 (P < 0.0001). OSA severity strongly correlated with Friedman Tongue Position grade, (r = 0.389, P < 0.0001), Friedman clinical staging, (r = 0.331, P = 0.0007). Of significance, only 6.9% of patients with mild OSA had a >50% collapse of the base of tongue region, as compared to 65.9% of patients with severe OSA.

CONCLUSION

There is good correlation between clinical examination parameters and the severity of OSA. An algorithm for surgical treatment of OSA should acknowledge both the site of obstruction and the severity of disease.
Thyroid Cancer in Children: Management and Outcome Experience of a Referral Center
Authors: Popovtzer Aron , Shpitzer Thomas , Bahar Gideon , Feinmesser Raphael , Segal Karol
Published: September 2006

OBJECTIVE

To shed light on the discrepancy between the advanced stage at presentation and high recurrence rate of well‐differentiated thyroid cancer in children and the overall good survival.

DESIGN AND METHODS

The files of 75 children with well‐differentiated thyroid cancer treated from 1954 to 2001 in a major tertiary‐care hospital were reviewed for disease course, management, and outcome.

RESULTS

Sixty patients (80%) had positive neck metastases with involvement of central compartment lymph nodes in all, lateral neck nodes in 36, and distant metastases in 4. Sixty‐seven patients underwent total thyroidectomy with adjuvant radioiodine treatment and 8 underwent hemithyroidectomy; all had concomitant neck treatment. The rate of local (5%) and neck (9%) recurrence was similar to the total rate reported in adults. Total thyroidectomy led to a significantly lower recurrence rate (7.5%) than hemithyroidectomy (38%; P < 0.005). Type of neck dissection did not affect recurrence or appearance of distant metastases. All deaths (n = 2) were due to distant metastases, whereas 30% of adult deaths are due to local or neck disease.

CONCLUSIONS

The treatment of choice for well‐differentiated thyroid cancer in young patients is total thyroidectomy. Neither regional disease at presentation nor recurrences affect survival.
Laryngotracheal Separation Surgery: Outcome in 60 Patients
Authors: Zocratto Orlando B. , Savassi‐Rocha Paulo R. , Paixão Rafael M. , Salles José M. P.
Published: September 2006

OBJECTIVE

To determine the outcome of laryngotracheal separation (LTS) in 60 patients in terms of the control and prevention of severe and persistent aspiration, morbidity and mortality, reversibility rate, and the influence of the presence of a tracheostomy.

STUDY DESIGN

Retrospective study.

RESULTS

LTS showed significant efficacy rates in terms of both treatment (87%) and prevention (100%) of pulmonary aspiration. Twenty‐six (43%) patients developed postoperative complications. A tracheocutaneous fistula of the proximal tracheal stump was observed in 14 (23%) patients and was the most frequent complication, especially in patients with a therapeutic indication (P = 0.028) and in those with a tracheostomy (P = 0.058). Reversion of LTS was possible in 12 (20%) patients, mainly those with a prophylactic indication (P = 0.005). However, the rates of complications (58%) and inefficacy (27%) of reversion surgery were high.

CONCLUSION

LTS is effective in the elimination and prevention of clinically intractable aspiration. The procedure is potentially reversible. However, the frequency of complications for both LTS and reversion surgery is significant.
Adenoidectomy: Long‐term Follow‐Up
Authors: Joshua Benzion , Bahar Gideon , Sulkes Jaqueline , Shpitzer Thomas , Raveh Eyal
Published: September 2006

OBJECTIVE

To assess the long‐term (3‐5 years) success of adenoidectomy and reasons for unsatisfactory results.

STUDY DESIGN AND SETTING

The parents of all children who underwent adenoidectomy alone at a major tertiary center from 1998 to 2000 were asked to complete a questionnaire assessing their child's well‐being and symptomatology 3‐5 years after surgery; some were invited for follow‐up. Symptom improvement, persistent symptoms, and adenoid regrowth were evaluated.

RESULTS

Among the 206 parents who complied, 74%‐87% reported improvement in all main symptoms: nasal obstruction, snoring, chronic rhinorrhea, hyponasal speech, and obstructive sleep disorder. At follow‐up (n = 36), the symptomatic patients had significantly more anatomic nasal abnormalities (P = 0.01) and a higher rate of significant adenoid enlargement (P = 0.08), 3 patients (19%) vs none (0%).

CONCLUSIONS AND SIGNIFICANCE

Adenoidectomy alone is satisfactory treatment for nasal obstruction and obstructive sleep apnea in selected children. Though some adenoid regrowth is not rare, clinically significant adenoid regrowth is infrequent. Persistent or recurrent symptoms are attributable mainly to nasal pathology.
Image‐Guided Frontal Trephination: A Minimally Invasive Approach for Hard‐To‐Reach Frontal Sinus Disease
Authors: Zacharek Mark A. , Fong Karen J. , Hwang Peter H.
Published: September 2006

OBJECTIVES

Peripherally located frontal sinus pathology may be unreachable with standard endoscopic techniques. Patients with superiorly or laterally based lesions often undergo osteoplastic flap with or without obliteration. Image‐guided frontal trephination (IGFT) can localize pathology and provide excellent exposure. We present 13 patients in whom this technique was applied.

STUDY DESIGN

Medical records of 13 patients undergoing IGFT were retrospectively reviewed.

RESULTS

The patients' mean age was 49.2 years, (range 14‐79); follow‐up time was 29.9 months (range 12‐39). Indications for IGFT were superiorly or laterally based mucoceles (3), fibrous dysplasia or osteoma (3), type 4 frontal cells (3), and frontal recess stenosis or ossification (4). In five patients, IGFT was combined with endoscopic transethmoid frontal sinusotomy; eight patients were treated through a trephination approach, and three patients underwent trephination with unilateral frontal sinus obliteration. One patient required revision; all others remain symptom free.

CONCLUSIONS/SIGNIFICANCE

IGFT offers an attractive alternative to osteoplastic flap.
Disease Severity in Acute Bacterial Rhinosinusitis is Greater in Patients Infected with Streptococcus Pneumoniae Than in Those Infected with Haemophilus Influenzae
Authors: Benninger Michael , Brook Itzhak , Farrell David J.
Published: September 2006

BACKGROUND

Streptococcus pneumoniae and Haemophilus influenzae are the most common causative pathogens in acute bacterial rhinosinusitis. A post hoc pooled analysis of four multinational Phase III clinical trials was conducted to compare disease severity in acute bacterial rhinosinusitis caused by S. pneumoniae or H. influenzae.

METHODS

Patients were evaluated for acute bacterial rhinosinusitis clinician‐assessed symptom severity and radiologic findings (total opacity, mucosal thickening, and air‐fluid levels on maxillary sinus x‐rays). Specimens for bacteriologic identification were collected by maxillary sinus tap, or by selective middle meatal cultures (sinus aspirates or swabs).

RESULTS

Compared with patients infected with H. influenzae (n = 106), patients infected with S. pneumoniae (n = 143) showed a statistically significant higher incidence of severe disease (39.2% vs 23.6%, P = 0.0097) and total opacity (46.2% vs 29.2%, P = 0.0085). Mucosal thickening (47.6% vs 56.6%, P = 0.1616) and air‐fluid levels (49% vs 56.6%, P = 0.2500) were comparable between the two groups.

CONCLUSIONS

In acute bacterial rhinosinusitis, infection with S. pneumoniae is associated with more severe clinical symptoms and radiographic total opacification findings than infection with H. influenzae.
Herbal Medicines for the Treatment of Rhinosinusitis: A Systematic Review
Authors: Guo Ruoling , Cantery Peter H. , Ernst Edzard
Published: September 2006

OBJECTIVES

To assess the efficacy of herbal medicines for treating rhinosinusitis.

DATA SOURCE

Five electronic databases, bibliographies of located papers, manufacturers, and experts in the field.

REVIEW METHODS

Inclusion of randomized clinical trials (RCT) testing any herbal medicine in rhinosinusitis, as sole or adjunctive treatment. Data were extracted independently by two reviewers following a predetermined protocol.

RESULTS

Ten RCTs, testing six different herbal products against placebo (8 RCTs) or “no additional treatment” (2 RCTs) were included. Four RCTs tested Sinupret as adjunctive treatment for either acute (3 RCTs) or chronic (1 RCT) rhinosinusitis. The quality of these studies varied, but two in acute sinusitis, including the largest and best quality study, and one in chronic sinusitis reported significant positive findings. Three RCTs tested bromelain in either acute sinusitis (2 RCTs) or patients of mixed diagnosis (chronic and acute sinusitis), and all reported some positive findings. Metanalysis of the two RCTs in acute sinusitis suggested that adjunctive use of bromelain significantly improves some symptoms of acute rhinosinusitis. Single RCTs were identified for 4 other herbal products (Esberitox, Myrtol, Cineole, and Bi Yuan Shu) as treatments for sinusitis, all reported some positive results. The median methodological quality score was 3 of 5.

CONCLUSION

Evidence that any herbal medicines are beneficial in the treatment of rhinosinusitis is limited, particularly in chronic rhinosinusitis. There is encouraging evidence that Sinupret and bromelain may be effective adjunctive treatments in acute rhinosinusitis. Positive results from isolated RCTs of four other herbal products require independent replication.
Effects of Ototopic Steroid and NSAIDS in Clearing Middle ear Effusion in an Animal Model
Authors: Cutler Jeffrey L. , Wall Michael , Labadie Robert F.
Published: September 2006

OBJECTIVE

A model of otitis media with effusion (OME) has been developed in the Sprague‐Dawley (SD) rat. This model was used to study the effects of an ototopic steroid and nonsteroidal anti‐inflammatory drug (NSAID) on lipopolysaccharide (LPS)‐induced OME.

STUDY DESIGN

Twenty‐six rats were randomized into 4 groups: saline solution, LPS, NSAID + LPS, and steroids + LPS. Test substance was injected into the middle ear at 0, 2, and 4 hours. The effusion was collected at 2, 4, and 6 hours. Statistical analysis of effusion volume and albumin concentration was performed.

RESULTS

The LPS group demonstrated statistically significant increase in both effusion volume and albumin concentration compared with saline solution. Intergroup comparison revealed significantly less effusion volume in the steroid group and less albumin concentration in the NSAID group when compared with the LPS group.

CONCLUSIONS

Transtympanic steroid reduced LPS induced middle ear effusion while NSAID reduced albumin concentration in the rat model.

SIGNIFICANCE

Our results lend support to the current use of anti‐inflammatory ototopicals in the treatment of inflammatory middle ear disease.
Objective Measurement of Vocal Fatigue in Classical Singers: A Vocal Dosimetry Pilot Study
Authors: Carroll Thomas , Nix John , Hunter Eric , Emerich Kate , Titze Ingo , Abaza Mona
Published: September 2006

OBJECTIVES

To collect objective vibration dose data on singers and relate them to subjective measurements of vocal fatigue.

STUDY DESIGN AND SETTING

Seven subjects completed a 2‐week study period. The National Center for Voice and Speech (NCVS) dosimeter recorded vocal load, soft phonation tasks, and subjective soft voice ratings. Three vocal doses (time, distance, and cycle) were measured in classical singers' larynges during an intensive practice period.

RESULTS

Spikes in vocal load are reflected as harsher subjective ratings on the same day as well as 24‐72 hours later. When at least 48 hours of vocal rest occurred before a vocal load, improved subjective evaluations were seen after the load.

CONCLUSIONS

The NCVS dosimeter appears to be an effective tool for data collection on prolonged use of the voice.

SIGNIFICANCE

This is the first multi‐day study comparing objective and subjective data on vocal fatigue in a group of professional singers.
An unusual high-Mg garnet–spinel orthopyroxenite from southern India: evidence for ultrahigh-temperature metamorphism at high-pressure conditions
Authors: SAJEEV K. , SANTOSH M.
Published: September 2006

We report here a garnet–spinel orthopyroxenite in close association with an ultrahigh-temperature (UHT) granulite from the central part of the Madurai Granulite Block in southern India. The garnet–spinel orthopyroxenite is almost entirely composed of orthopyroxene, spinel and rare garnet in a granular texture. Spinels in the rock are characterized by high Mg (XMg = 0.69–0.71) with low Cr and Fe3+, consistent with compositions reported from spinels occurring within xenoliths in kimberlites and high pressure–temperature (P–T) Alpine complexes. The orthopyroxenes have high Al content (Al2O3 up to 4.85 wt%), typical of equilibration under high P–T conditions. The P–T estimates derived for the garnet–spinel orthopyroxenite indicate temperatures of around 1000°C and pressures exceeding 17 kbar. The data indicate that UHT metamorphism in this locality traversed from above 17 kbar to 11 kbar prior to the final stage of isothermal decompression. Our study reports the highest pressures obtained by far, for extreme crustal metamorphism in southern India and elsewhere in Gondwana. The multi-stage decompression observed in the UHT rocks associated with the high P–T garnet–spinel orthopyroxenite could be correlated to extension of the crust and possibly of the lithospheric mantle and/or its delamination, with the asthenospheric mantle as the ultimate heat source, during the final stage of amalgamation of the Gondwana supercontinent.
Chemotherapy alone in laryngeal squamous cell carcinoma
Authors: Bonfils P , Trotoux J , Bassot V
Published: September 2006

Aims: To evaluate the results of chemotherapy alone in patients with invasive squamous cell carcinoma of the larynx who have achieved a complete clinical response after an induction chemotherapy protocol.

Methods: A comparison of results in a group of complete responders managed with a chemotherapy alone protocol, matched with those of an incomplete responder group managed with conventional modalities.

Results: The survival rate of the complete responder group was significantly higher than that of the incomplete responder group. No statistically significant difference was noted between the two groups in terms of local failure and nodal recurrence.

Conclusion: Our results confirm the fact that chemotherapy alone is a viable option in selected patients with carcinoma of the larynx who have achieved a complete clinical response after an induction chemotherapy protocol. This therapeutic approach allows surgery and/or radiation therapy to be reserved for the management of metachronous second primary tumours.
Prevalence of HIV infection among young adult injecting and non-injecting heroin users in Spain in the era of harm reduction programmes: gender differences and other related factors
Authors: BARRIO G. , De La FUENTE L. , TORO C. , BRUGAL T. M. , SORIANO V. , GONZALEZ F. , BRAVO M. J. , VALLEJO F. , SILVA T. C. ,   the Project Itinere Group
Published: September 2006

The aims were to assess the prevalence of HIV infection among young adult heroin users, including injecting heroin users (IHUs) and non-injecting heroin users (NIHUs), and to explore the differences by gender and other factors. The design was a cross-sectional cohort study between April 2001 and December 2003, which included 961 current heroin users (HU), aged 18–30 years: 422 in Madrid, 351 in Barcelona and 188 in Seville; 621 were IHUs and 340 were NIHUs. All were street-recruited by chain referral methods. Face-to-face interviews were conducted using a structured questionnaire with computer-assisted personal interviewing (CAPI). Samples for HIV testing (dried blood spot) were collected and tested with ELISA and Western Blot. Bivariate, logistic regression, and classification and regression tree analyses were performed. The overall prevalence of HIV infection among IHUs was 25·8% (95% CI 22·3–29·3) [32·4% (95% CI 26·6–38·1) in Madrid, 20·5% (95% CI 15·6–25·4) in Barcelona, and 20·6% (95% CI 9·8–31·4) in Seville], whereas in NIHUs it was 4·0% (95% CI 2·1–6·7), with no differences among cities. The prevalence was significantly higher in women than in men in NIHUs (10·9%, 95% CI 4·3–17·5 vs. 1·7%, 95% CI 0·5–4·2) and was non-significantly higher in IHUs (30·4%, 95% CI 23·0–37·8 vs. 24·1%, 95% CI 20·1–28·1). HIV prevalence in short-term IHUs was 12·9% (CI 8·8–17·02), with no differences among cities. In the logistic analysis, the variables associated with infection in IHUs were ever having injected with used syringes (OR 3·4, 95% CI 2·2–5·3), ever having been in prison (OR 2·6, 95% CI 1·6–4·0), and heroin as the first drug injected at least weekly (OR 2·3, 95% CI 1·1–4·5). Factors positively associated with HIV infection in NIHUs were female sex (OR 8·7, 95% CI 2·6–29·2) and age >25 years (OR 3·1, 95% CI 0·9–11·1), while primary educational level was inversely associated (OR 0·26, 95% CI 0·1–0·9). Although there are important geographic differences, HIV prevalence in IHUs remains high, even in short-term IHUs, whereas it was almost six times lower in NIHUs. The prevalence in women is higher than in men, particularly among NIHUs. A wide range of preventive strategies should be developed, aimed primarily at empowering women to negotiate safe sex.
Energetic nitrogen ions within the inner magnetosphere of Saturn
Authors: Sittler E. C. , Johnson R. E. , Smith H. T. , Richardson J. D. , Jurac S. , Moore M. , Cooper J. F. , Mauk B. H. , Michael M. , Paranicas C. , Armstrong T. P. , Tsurutani B.
Published: September 2006

We investigate the importance of nitrogen ions within Saturn's magnetosphere and their contribution to the energetic charged particle population within Saturn's inner magnetosphere. This study is based on the Voyager observations of Saturn's magnetosphere and Cassini observations. The latter have shown that water group ions dominate both the plasma and energetic particle populations but that nitrogen ions over a broad range of energies were observed at ∼5% abundance level. In the outer magnetosphere, methane ions were predicted to be an important pickup ion at Titan and were detected at significant levels in the outer magnetosphere and at Titan. O+ ions were found to be the dominant heavy ion in the outer magnetosphere, ∼60%, with methane ions being ∼30% of the heavy ions and N+ being a few percent. The two major sources of nitrogen ions within Saturn's magnetosphere are Titan's atmosphere and primordial nitrogen trapped in the icy crust of Saturn's moons and its ring particles deep within the magnetosphere. It is important to understand the source, transport, and sinks of nitrogen in order to determine whether they have a primordial origin or are from Titan's atmosphere. The energetic component is important, since it can come from Titan, be implanted into the surfaces of the icy moons, and reappear at plasma energies via sputtering obfuscating the ultimate source. As we will show, such implantation of nitrogen ions can produce interesting chemistry within the ice of Saturn's moons. The emphasis will be on the nitrogen, but the oxygen and other water group ions are also considered. We argue that neutral clouds of heavy atoms and molecules within Saturn's outer magnetosphere may be the dominant source of energetic heavy ions observed within the inner magnetosphere. Pickup heavy ions in the outer magnetosphere have energies ∼1–4 keV when born. If they diffuse radially inward, while conserving the first and second adiabatic invariants, they can have energies greater than several hundred keV inside of Dione's L shell. We will show how observations relate to the various sources and acceleration processes such as ionization, collisions, wave‐particle interactions, and radial diffusion.
Estimating changes in global vegetation cover (1850–2100) for use in climate models
Authors: Wang Audrey , Price David T. , Arora Vivek
Published: September 2006

Historical changes in global cropland area based on estimates of Ramankutty and Foley (1999), and projections of future changes under IPCC SRES development scenarios taken from the IMAGE 2 model, were combined with a simple classification of present‐day satellite data. These data were used to estimate annual changes in area fractions occupied by primary plant functional types (PFTs) between 1850 and 2100 using two different approaches. The linear interpolation approach assumed that natural vegetation area varies in inverse proportion to cropland area. The rule‐based approach added simple transition rules to define the sequence by which natural PFTs are converted to agriculture (e.g., grassland before forest) and by which abandoned cropland reverts to natural vegetation. In both approaches, constraints were imposed to ensure the simulated PFT composition was consistent with available information. The resulting time series data can be used in coupled biosphere‐atmosphere models, and in uncoupled global climate models, to represent time‐varying land cover.
Influence of 13C‐enriched foliage respired CO2 on δ13C of ecosystem‐respired CO2
Authors: Mortazavi Behzad , Chanton Jeffrey P. , Smith Matthew C.
Published: September 2006

The δ13C of slash pine foliage dark‐respired CO2 (δ13CF) was measured at temperatures ranging from 6.6° to 30°C. The δ13CF was 13C‐enriched initially after dark by as much as 9‰ and declined toward an asymptotic value after a few hours in the dark. Maximum enrichment in δ13CF occurred at the lowest temperatures and the decline in δ13CF toward the asymptotic value took longer at lower temperatures. The effect of this temporal variation in foliage enriched CO2 on determination of the δ13CO2 of ecosystem respiration (δ13CR) was investigated using two approaches by measuring the nighttime CO2 concentration and δ13CO2 ratio in a 30‐m‐tall pine forest in Florida, United States. The first approach (time series) consisted of making measurements at a single height at midcanopy from 1 hour after sunset until 0200 local time. The second approach (profile) consisted of making measurements at multiple heights from ground level to the top of the canopy synoptically prior to dawn. For each method a Keeling plot was used to estimate the δ13CR. The δ13CR values determined with the time series were 13C‐enriched relative to those determined from profiles on average by 1.0‰ and by as much as 3.1‰. A mass balance was used to determine the impact of the nonconstancy of δCF on the overall Keeling plot intercepts. For the months examined, results indicate that (1) the enrichment in the Keeling intercepts determined from time series compared to those determined from profiles was consistent with the addition of nighttime foliage respired 13C‐enriched CO2 and (2) Keeling plots determined from midcanopy heights appear linear despite the addition of temporally variable source δ13CO2 (range: 4‰). A common approach that specifies the time (predawn) and spatial distribution (multiple heights) for CO2 collection is suggested to improve intercomparisons of δ13CR from different ecosystems.
S velocity reversal in the mantle transition zone
Authors: Vinnik L. , Farra V.
Published: September 2006

The transition zone differs from the rest of the mantle by high positive P and S wave velocity gradients. However, by applying S receiver function technique to recordings of about 50 globally distributed stations, in 7 regions we obtain evidence of negative discontinuity at a depth around 500 km. Four of these regions correspond to the well known hotspots. No other hotspots are sampled by our observations at this depth. Our modeling suggests that the negative discontinuity is hardly an effect of anisotropy of wadsleyite. More likely, it is caused by isotropic S velocity reduction of around 0.2 km/s. Origin of the low velocity can be related to enhanced water content in wadsleyite.
Critique of the tracer‐tracer correlation technique and its potential to analyze polar ozone loss in chemistry‐climate models
Authors: Lemmen Carsten , Müller Rolf , Konopka Paul , Dameris Martin
Published: September 2006

The tracer‐tracer correlation technique (TRAC) has been widely employed to infer chemical ozone loss from observations. Yet, its applicability to chemistry‐climate model (CCM) data is disputed. Here, we report the successful application of TRAC on the results of a CCM simulation. By comparing TRAC‐calculated ozone loss to ozone loss derived with the passive ozone method in a chemistry transport model we differentiate effects of internal mixing and cross vortex boundary mixing on a TRAC reference correlation. As a test case, we consider results of a cold Arctic winter/spring episode from an E39/C experiment, where typical features, for example, sufficient polar stratospheric cloud formation potential, denitrification and dehydration, and intermittent and final stratospheric warming events, are simulated. We find that internal mixing does not impact the TRAC‐derived reference correlation at all. Mixing across the vortex boundary would lead to an underestimation of ozone loss by ∼10% when calculated with TRAC. We provide arguments that TRAC is a consistent and conservative method to derive chemical ozone loss and can be used to extract its chemical signature also from CCM simulations. As a consequence, we will be able to provide a lower bound for chemical ozone loss for model simulations where a passive ozone tracer is not available.
Ultrafast processes in OClO molecules excited by femtosecond laser pulses at 386–409nm
Authors: Stert V. , Ritze H.-H. , Hertel I. V. , Radloff W.
Published: September 2006

Ultrafast dissociation dynamics in OClO molecules is studied, induced by femtosecond laser pulses in the wavelength region from 386to409nm, i.e., within the wide absorption band to the ÃA22 electronic state. The decay of the initially excited state due to nonadiabatic coupling to the close lying A12 and B22 electronic states proceeds with a time constant increasing from 4.6ps at 386nmto30ps at 408.5nm. Dissociation of the OClO molecule occurs after internal conversion within about 250fs. In addition, a minor channel of direct excitation of the A12 electronic state has been identified, the lifetime of which increases from a few 100fs at 386nmto2.2ps at 408.5nm. Simultaneous excitation of two neighboring vibrational bands in the ÃA22 state leads to a coherent oscillation of the parent ion signal with the frequency difference of both modes.
Proton line narrowing in solid-state nuclear magnetic resonance: New insights from windowed phase-modulated Lee-Goldburg sequence
Authors: Leskes Michal , Madhu P. K. , Vega Shimon
Published: September 2006

We present here a bimodal Floquet analysis of the windowed phase-modulated Lee-Goldburg (wPMLG) sequence for homonuclear dipolar decoupling. One of the main criteria for an efficient homonuclear dipolar decoupling scheme is an effective z-rotation condition. This is brought about by the presence of radio-frequency imperfections in the pulse sequence together with a systematic manipulation of the wPMLG pulses. Additional improvement in the H1 spectral resolution was obtained by a proper understanding of the off-resonance dependence of the wPMLG irradiation scheme based on bimodal Floquet theory. Numerical investigations further corroborate both theoretical and experimental findings. Theoretical analysis points to accidental degeneracies between the cycle time of the wPMLG sequence and the rotor period leading to the experimentally observed off-resonance dependence of the resolution. Two-dimensional H1–H1 homonuclear single-quantum correlation spectra of model amino acids are also presented, highlighting the improved spectral resolution of wPMLG sequences.
Size-dependent alternation of magnetoresistive properties in atomic chains
Authors: Durgun E. , Senger R. T. , Mehrez H. , Sevinçli H. , Ciraci S.
Published: September 2006

Spin-polarized electronic and transport properties of carbon atomic chains are investigated when they are capped with magnetic transition-metal (TM) atoms like Cr or Co. The magnetic ground state of the TM-Cn-TM chains alternates between the ferromagnetic (F) and antiferromagnetic (AF) spin configurations as a function of n. In view of the nanoscale spintronic device applications the desirable AF state is obtained for only even-n chains with Cr; conversely only odd-n chains with Co have AF ground states. When connected to appropriate metallic electrodes these atomic chains display a strong spin-valve effect. Analysis of structural, electronic, and magnetic properties of these atomic chains, as well as the indirect exchange coupling of the TM atoms through non-magnetic carbon atoms are presented.
High magnetoresistance and low coercivity in electrodeposited Co∕Cu granular multilayers
Authors: Ghosh S. K. , Grover A. K. , Chowdhury P. , Gupta S. K. , Ravikumar G. , Aswal D. K. , Kumar M. Senthil , Dusane R. O.
Published: September 2006

Co ∕ Cu multilayers were electrodeposited from a single solution electrolyte. By reducing the magnetic layer thickness from 1to0.2nm, samples with heterogeneous mixture of ferromagnetic and superparamagnetic clusters have been made. Magnetization and magnetotransport measurements revealed the structured evolution of the multilayer granular samples. With critical thickness of tCo∼0.5nm, room temperature magnetoresistance of 7% was obtained at 2kOe with hysteresis of 70Oe. The large magnetoresistance obtained in granular multilayers is attributed to the presence of a range of sizes for the Co particles.
Subband electronic temperatures and electron-lattice energy relaxation in terahertz quantum cascade lasers with different conduction band offsets
Authors: Vitiello Miriam S. , Scamarcio Gaetano , Spagnolo Vincenzo , Worrall Chris , Beere Harvey E. , Ritchie David A. , Sirtori Carlo , Alton Jesse , Barbieri Stefano
Published: September 2006

The electronic temperatures of the conduction subbands, the local lattice temperature, and the electron-lattice energy relaxation times (τE) in bound-to-continuum GaAs∕AlxGa1−xAs quantum cascade lasers, operating at 2.9 and 2THz, are reported. This information has been gathered from the analysis of microprobe photoluminescence spectra collected during device continuous wave operation. We find that the electronic distributions in both the active region and the injector are thermalized and that all subbands share the same electronic temperature. The efficiency of electron cooling increases with the conduction band offset.
Molecular-scale imaging of unstained deoxyribonucleic acid fibers by phase transmission electron microscopy
Authors: Takai Yoshizo , Nomaguchi Tsunenori , Matsushita Shuhei , Kimura Yoshihide
Published: September 2006

The molecular structure of deoxyribonucleic acid (DNA) fibers was observed by a phase reconstruction method called three-dimensional Fourier filtering using a 200kV transmission electron microscope. The characteristic helical structure and the spacing of adjacent base pairs of DNA were partially resolved due to an improved signal-to-noise ratio and resolution enhancement by the phase reconstruction although the molecular structure was damaged by the electron beam irradiation. In the spherical aberration-free phase images, the arrangements of single atom-sized spots forming sinusoidal curves were sometimes observed, which seem to be the contrast originating in the sulfur atoms along the main chains.
Effect of interface passivation on the magnetoresistance of granular magnetite Fe3(1−δ)O4
Authors: Rybchenko S. I. , Fujishiro Y. , Takagi H. , Awano M.
Published: September 2006

The reductive passivation of granular interface was proposed to enhance the tunneling magnetoresistance of bulk granular magnetite. For this, an annealing in paraffin wax has been applied. As a result, the low-field magnetoresistance response was increased up to 8% at 300K and 32% at 130K. The effect is attributed to the passivation-induced depletion of density of the tunneling-active spin-depolarized interface states. The obtained results indicate the important role of interface states in tunneling contacts with magnetite electrodes and suggest a way to control these states.
Effective organic-based connection unit for stacked organic light-emitting devices
Authors: Law C. W. , Lau K. M. , Fung M. K. , Chan M. Y. , Wong F. L. , Lee C. S. , Lee S. T.
Published: September 2006

A bilayer connection unit of Mg-doped Alq3 and F4-TCNQ-doped m-MTDATA was investigated for application in stacked organic light-emitting device. This connection unit led to a stacked OLED with a luminous efficiency twice that of a single-unit OLED. Electronic structures, including relevant electron energy levels, of the various interfaces in the stacked OLED were studied by using ultraviolet photoemission spectroscopy and used to discuss the working mechanisms of the stacked OLED. The p-type dopant F4-TCNQ was shown to induce a large band bending of 1.36eV and facilitates efficient carrier injection from the connection units into the carrier-transporting layers.
Ohmic contacts to plasma etched n-Al0.58Ga0.42N
Authors: Miller M. A. , Mohney S. E. , Nikiforov A. , Cargill G. S. , Bogart K. H. A.
Published: September 2006

Plasma etching is required to expose n-AlxGa1−xN layers for bottom-emitting ultraviolet light emitting diodes grown on sapphire. However, etching can increase the difficulty of forming Ohmic contacts. X-ray photoelectron spectroscopy and cathodoluminescence reveal how the semiconductor changes with etching and help explain why it becomes more difficult to form an Ohmic contact. A V∕Al∕V∕Au metallization has been investigated for Ohmic contacts to n-Al0.58Ga0.42N etched with a BCl3∕Cl2∕Ar chemistry. Increased V thickness and higher annealing temperatures were required to obtain a specific contact resistance of 4.7×10−4Ωcm2 for etched n-Al0.58Ga0.42N compared to optimized contacts on unetched films.
Field effects on electron conduction through self-assembled monolayers
Authors: Hwang Gwo-Jen , Jeng Pei-Ren , Lien Chenhsin , Chen C. S. , Tsao Yung-Shiang , Hwang Hung-Shun , Xu Sheng-Quan , Hong T. M. , Chou Y. C.
Published: September 2006

The electronic conduction through the self-assembled monolayer (SAM) can be modulated by the electric potential applied to the silicon gate electrode surrounding the SAM. The dependence of the current through SAM on the gate voltage can be explained that the renormalized molecular energy levels are swept through the window between the Fermi levels of the source and drain electrodes. The effects of the lowest unoccupied molecular orbital and a hybrid energy level near the Fermi level in the transmission spectrum can be identified.
InP nanobridges epitaxially formed between two vertical Si surfaces by metal-catalyzed chemical vapor deposition
Authors: Yi S. S. , Girolami G. , Amano J. , Saif Islam M. , Sharma S. , Kamins T. I. , Kimukin I.
Published: September 2006

The heteroepitaxial growth of III-V compound semiconductors on Si would enable the integration of high-performance III-V materials with Si technology. We report epitaxial growth on (111)-oriented Si surfaces of highly aligned, single crystalline InP nanowires by chemical vapor deposition catalyzed by Au. We demonstrate laterally oriented InP nanowires bridging between vertical (111) Si surfaces formed by anisotropically etching a (110)-oriented Si substrate or the top Si layer of a silicon-on-insulator wafer. This method of connecting nanowires offers a facile way of integrating nanoscale III-V optoelectronic and photonic devices with Si.
Low hysteretic behavior of Al∕AlOx∕Al Josephson junctions
Authors: Lotkhov S. V. , Tolkacheva E. M. , Balashov D. V. , Khabipov M. I. , Buchholz F.-I. , Zorin A. B.
Published: September 2006

All-aluminum Josephson junctions with high-transparency barriers were fabricated using the shadow-evaporation technique and measured at low temperatures, T≈25mK. Due to the high junction transparency, the IV characteristics showed only small hysteresis with a retrapping-to-switching current ratio of up to 80%. The observed critical currents were as large as 80%-100% of the Ambegaokar-Baratoff values. High barrier quality was confirmed by the low subgap leakage currents in the quasiparticle branches, which makes the low hysteretic Al junctions promising for application in integrated rapid single-flux quantum - qubit circuitry.
Origin of forward leakage current in GaN-based light-emitting devices
Authors: Lee S. W. , Oh D. C. , Goto H. , Ha J. S. , Lee H. J. , Hanada T. , Cho M. W. , Yao T. , Hong S. K. , Lee H. Y. , Cho S. R. , Choi J. W. , Choi J. H. , Jang J. H. , Shin J. E. , Lee J. S.
Published: September 2006

The authors fabricated GaN-based light-emitting diodes (LEDs) on two different GaN templates with the same LED structure. One on thin GaN template (∼2μm) with high dislocation density [low (109cm−2)] grown by metal-organic vapor-phase epitaxy (sample A) and the other on thick GaN template (∼20μm) with comparatively low dislocation density [high (108cm−2)] by hydride vapor-phase epitaxy (sample B). In order to understand the mechanism of leakage current in LEDs, the correlation between current-voltage characteristics and etch pit density of LEDs was studied.
Compositional grading effects on permittivity temperature stability in (Ba,Sr)TiO3 films
Authors: Sigman J. , Clem P. G. , Nordquist C. D.
Published: September 2006

Compositionally graded (BaxSr1−x)TiO3 films are deposited on Pt∕Ti∕SiO2∕Si via chemical solution deposition to investigate permittivity temperature stability improvement. Dielectric responses and temperature coefficients of capacitance (TCCs) are monitored as function of the grading sequence and direction. Downgraded (decreasing Ba∕Sr ratio with film thickness) films universally display the lowest TCC values. BaTiO3-rich films display finer grain sizes which appear to be propagated into overlying layers, apparently suppressing ferroelectric character. By applying this microstructure effect, properties may be tailored to develop more temperature-stable capacitor elements for microwave devices.
Modified local environment and enhanced near-infrared luminescence of Sm3+ in chalcohalide glasses
Authors: Yang Zhiyong , Tang Gao , Luo Lan , Chen Wei
Published: September 2006

Near-infrared luminescence properties of Sm3+ in Ge–Ga–Se and GeSe2–Ga2Se3–CsI glasses were studied and the local environments of Sm3+ were investigated. Strong 1.24 and 1.49μm fluorescence bands with respective bandwidths of 48 and 60nm were observed. About 540μs fluorescence lifetimes were obtained for the two emissions. As CsI was introduced to Ge–Ga–Se glasses, the luminescence properties were greatly enhanced, especially when I∕Ga ratio reaches 1. This enhancement can be attributed to decreased local phonon mode which dominates the multiphonon relaxation. The Sm3+-doped GeSe2-based chalcohalide glasses can be promising materials for optical fiber amplifiers operating at 1.22–1.28 and 1.46–1.53μm bands.
Nucleolar trafficking is essential for nuclear export of intronless herpesvirus mRNA
Authors: Boyne James R. , Whitehouse Adrian
Published: September 2006

The nucleolus is the largest subnuclear structure and is plurifunctional in nature. Here, we demonstrate that nucleolar localization of a key herpesvirus regulatory protein is essential for its role in virus mRNA nuclear export. The herpesvirus saimiri ORF57 protein is a nucleocytoplasmic shuttle protein that is conserved in all herpesviruses and orchestrates the nuclear export of viral intronless mRNAs. We demonstrate that expression of the ORF57 protein induces nucleolar redistribution of human TREX (transcription/export) proteins that are involved in mRNA nuclear export. Moreover, we describe a previously unidentified nucleolar localization signal within ORF57 that is composed of two distinct nuclear localization signals. Intriguingly, point mutations that ablate ORF57 nucleolar localization lead to a failure of ORF57-mediated viral mRNA nuclear export. Furthermore, nucleolar retargeting of the ORF57 mutant was achieved by the incorporation of the HIV-1 Rev nucleolar localization signal, and analysis demonstrated that this modification was sufficient to restore viral mRNA nuclear export. This finding represents a unique and fundamental role for the nucleolus in nuclear export of viral mRNA.