bluuebunny/crossref_metadata_2025 huggingface dataset:
Craniofacial Osteoma: Clinical Presentation and Patterns of Growth
Authors: Halawi Akaber M. , Maley Joan E. , Robinson Robert A. , Swenson Casey , Graham Scott M.
Published: March 2013

Background

This study was designed to investigate the clinical features and the growth rate of craniofacial osteomas.

Methods

Retrospective chart review was performed of 200 cases of craniofacial osteomas diagnosed from January 2001 to September 2011. Data pertinent to patient and osteoma lesion characteristics were collected. Histology of operated cases was reviewed. Computer tomography (CT) charts were reviewed and those with multiple images were analyzed for growth characteristics.

Results

One hundred forty-nine patients met our inclusion criteria. Eighty-nine percent of these osteomas were found incidentally. Forty-three percent were in the frontal sinus. Fifteen percent of the patients complained of headaches and only 6.71% of patients with osteoma had headaches congruent with osteoma location. Thirty-one percent of CT scans had sinus mucosal disease; only 8% had mucosal disease adjacent to the osteoma. Ten of the 149 patients underwent surgery for cosmetic and/or rapidly growing osteomas. Thirteen patients had intestinal tubular adenoma, and one was genetically positive for Gardner's syndrome. Fifty-two patients had multiple CT scans that were included in growth rate analysis. The mean linear growth rate of osteomas was estimated to be 0.117 mm/yr (95% CI, 0.004, 0.230) in maximal dimension, assuming linear growth. A descriptive analysis of osteoma growth divided the osteomas into several intervals and studied the growth rate separately in each interval. The median change in maximum dimension was different in each interval in a nonsystematic manner, ranging from −0.066 mm, over 3- to 9-month interval (interquartile range [IQR] = −0.404–1.069), to 0.369 mm over 9- to 15-month interval (IQR = −0.032–0.855), and 0.082 mm over 45- to 51-month interval (IQR = −0.000–0.197). There was no significant association between tumor size, location, or complications.

Conclusion

Craniofacial osteomas are slow-growing lesions with no specific growth pattern and rare complications. Their clinical behavior is ill defined and justifies a conservative approach toward asymptomatic lesions with close radiological follow-up.
Role of α2-adrenoceptors in Electrical Field Stimulation–induced Contraction of Pig Nasal Mucosa and Pharmacologic Characterization of a Novel α2C-adrenoceptor Agonist
Authors: Corboz Michel R. , Rivelli Maria A. , Shah Himanshu , Boyce Christopher W. , McCormick Kevin D. , Chapman Richard W. , Hunter John C.
Published: March 2013

Background

Blood vessels of the nasal mucosa are richly innervated by sympathetic nerves and neural mechanism is of great interest in upper respiratory tract disorders. This study was designed to determine the role of α2-adrenoceptors and, more specifically, α2C-adrenoceptors, on neurogenic sympathetic vasoconstrictor responses in pig nasal mucosa, and to define the pharmacologic profile of a novel selective α2C-adrenoreceptor agonist.

Methods

Electrical field stimulation (EFS) was applied to nasal mucosa strips placed in an organ bath and attached to force displacement transducers for continuous recording of isometric tension. The affinity and functional activity of compound B for α2C-adrenoceptors were determined by binding analysis and the ability of compound B to stimulate [35S]GTPγS binding to the receptors. Compound B was also tested in a postjunctional α2C-adrenoreceptor bioassay.

Results

EFS-induced contractions were partly blocked by the α2-adrenoreceptor antagonist yohimbine (41.1%) and the α2C-adrenoreceptor antagonist JP-1302 had no effect. The α2-adrenoreceptor agonist clonidine, but not compound B, exerted a significant blockade (70.6%). Compound B had high affinity (Ki = 18 nM), produced potent agonist (EC50 = 279 nM) and good efficacy (Emax = 73%) responses at the α2C-adrenoceptors, and displayed good functional agonist potency in the human saphenous vein α2C-adrenoreceptor bioassay (pD2 = 6.2).

Conclusion

(1) Neurogenic vasomotor contractility is largely regulated through an α-adrenergic mechanism; (2) pig nasal mucosa possesses post- and prejunctional α2-adrenoceptors; (3) the α2C-adrenoreceptor subtype does not seem to be involved; and (4) compound B is a novel, highly selective, and potent α2C-adrenoreceptor agonist.
Platelet-activating Factor Nasal Challenge Induces Nasal Congestion and Reduces Nasal Volume in Both Healthy Volunteers and Allergic Rhinitis Patients
Authors: Muñoz-Cano Rosa , Valero Antonio , Roca-Ferrer Jordi , Bartra Joan , Sanchez-Lopez Jaime , Mullol Joaquim , Picado Cesar
Published: March 2013

Background

Platelet-activating factor (PAF) is a lipid mediator produced by most inflammatory cells. Clinical and experimental findings suggest that PAF participates in allergic rhinitis (AR) pathogenesis. The aim was to assess the PAF ability to induce clinical response in nasal airway after local stimulation.

Method

Ten nonatopic healthy volunteers (HVs) and 10 AR patients out of pollen season were enrolled. PAF increasing concentrations (100, 200, and 400 nM) were instilled into both nasal cavities (0, 30, and 60 minutes, respectively). Nasal symptoms (congestion, rhinorrhea, sneezing, itching, and total 4 symptom score and nasal volume between the 2nd and 5th cm (Vol2–5) using acoustic rhinometry (AcR), were assessed at −30, 0, 30, 60, 90, 120, and 240 minutes.

Result

PAF increased individual and total nasal symptom score in both HVs and seasonal AR (SAR) patients from 30 to 120 minutes (maximum score at 120’, p < 0.05). Nasal obstruction was the most relevant and lasting nasal symptom. PAF also induced a significant reduction of Vol2–5 at 90’ (27%), 120’ (38.7%), and 240’ (36.4%). No differences in the response to PAF nasal challenge were observed between HVs and SAR subjects in either clinical symptoms or AcR.

Conclusion

This is the first description of PAF effects on human nasal mucosa using a cumulative dose schedule and evaluated by both nasal symptoms and AcR. Nasal provocation with PAF showed long-lasting effects on nasal symptoms and nasal obstruction in HVs and in patients with SAR. Nasal challenge may be a useful tool to investigate the role of PAF in AR and the potential role of anti-PAF drugs.
Therapeutic Equivalence of Triamcinolone Acetonide Hydrofluoroalkane and Chlorofluorocarbon Nasal Inhalers in Patients with Seasonal Allergic Rhinitis
Authors: Schenkel Eric , Newman Kenneth B.
Published: March 2013

Background

Triamcinolone acetonide (TAA) has been reformulated as an hydrofluoroalkane (HFA) aerosol for intranasal use in patients with seasonal allergic rhinitis (SAR). This study compared the TAA HFA formulation with the previously available chlorofluorocarbon (CFC) nasal inhaler in a dose-ranging study.

Methods

This was a double-blind, parallel-group, multicenter study in 780 adults with SAR. Patients had a history of fall seasonal rhinitis and positive skin tests to ragweed. After meeting minimum symptom requirements during the run-in phase, patients were randomized to one of eight groups: TAA CFC or HFA at 14, 110, or 440 micrograms once daily or matching placebo. Treatment was continued for two weeks and patient completed a daily diary for reflective and instantaneous rating of nasal and ocular allergy symptoms.

Results

All active treatment groups were statistically superior to placebo with respect to the primary outcome variable, total nasal symptoms. Furthermore, the TAA HFA and TAA CFC formulations were statistically comparable over the dose range. Within each formulation, there was a significant mean reduction from baseline in the symptoms of rhinitis that increased with increasing dose. Ocular symptoms were also reduced with both formulations. Both preparations were well tolerated without any safety concerns.

Conclusion

In conclusion, a new formulation of TAA with a HFA propellant was found to be effective in the treatment of SAR and comparable with the previously available TAA CFC formulation. There was a dose response to TAA, with doses as low as 7 micrograms per nostril once daily producing statistically significant improvement in rhinitis symptoms.
Mini-nasoseptal Flap for Recalcitrant Sphenoid Sinusitis
Authors: Thompson Christopher F. , DeConde Adam S. , Chiu Alexander G. , Lee John M. , Suh Jeffrey D.
Published: March 2013

Background

Recalcitrant sphenoid sinusitis occurs in 27% of patients undergoing revision functional endoscopic sinus surgery. One of the main causes of disease recurrence in the sphenoid is cicatricial scarring of the ostium. Highly inflammatory lesions such as fungal balls or chronic mucoceles can predispose patients to restenosis. We present a novel use of a modified nasoseptal flap to cover exposed bone after sphenoid wide sinusotomy to prevent restenosis and expedite healing.

Methods

A case series was performed.

Results

The mini-nasoseptal flap was successful in preventing sphenoid ostium restenosis in nine patients undergoing endoscopic sinus surgery for highly inflammatory sphenoid sinus pathology with a mean postoperative follow-up of 8.4 months (range, 2–21 months). Patients had a mean of 2.3 prior sinus surgeries (range, 0–7 surgeries). Most common indications for the flap in this series included long-standing fungal sinusitis or fungal balls (n = 6) with or without significant sphenoid wall osteoneogenesis (n = 6). There were no significant side effects related to flap harvest or inset.

Conclusion

The mini-nasoseptal flap decreases the risk of restenosis after sphenoid sinusotomy by preventing circumferential cicatricial scarring and offers an effective surgical option on the spectrum of sphenoid surgical interventions in select patients.
Toward Photorealism in Endoscopic Sinus Surgery Simulation
Authors: Ruthenbeck Greg S. , Hobson Jonathan , Carney A. Simon , Sloan Steve , Sacks Raymond , Reynolds Karen J.
Published: March 2013

Background

Endoscopic sinus surgery (ESS) is the surgical standard treatment for chronic rhinitis/rhinosinusitis and nasal polyposis. There is a reported complication rate of 5–10% associated with this type of surgery. Simulation has been advocated as a means to improve surgical training and minimize the rates of complication and medical error. This study aimed to show how a virtual reality ESS simulator was developed, with particular emphasis on achieving satisfactory photorealism and surgical verisimilitude.

Methods

Sinus computed tomography scans were processed to create a triangle-based three-dimensional mesh model; this was incorporated into a spring-damper model of thousands of interconnected nodes, which is allowed to deform in response to user interactions. Dual haptic handpiece devices were programmed to simulate an endoscope and various surgical instruments. Textures and lighting effects were added to the mesh model to provide an accurate representation of the surgical field. Effects such as vasoconstriction in response to “virtual” decongestant were added.

Results

The final simulated endoscopic view of the sinuses accurately simulates the moist and glossy appearance of the sinuses. The interactive tissue simulation system enables the user to interactively cut and remove tissue while receiving accurate haptic feedback. A working prototype of the simulator has been developed that leverages recent advances in computer hardware to deliver a realistic user experience, both visually and haptically.

Conclusion

This new computer-based training tool for practicing ESS provides a risk-free environment for surgical trainees to practice and develop core skills. The novel use of customized precision force feedback (haptic) devices enables trainees to use movements during training that closely mimic those used during the actual procedure, which we anticipate will improve learning, retention, and recall.
Effects of Budesonide on the Expression of the Glucocorticoid Receptor-α in Nasal Polyp Epithelial Cells
Authors: Wang De-Sheng , Liu Qin-Song , Lai Hai-Chun
Published: March 2013

Background

This study explores effects of budesonide on the proliferation of nasal polyp epithelial cells and expression of the glucocorticoid receptor (GR) alpha in nasal polyp epithelial cells.

Methods

Primary cultured, purified, and identified the epithelial cells collected from nasal polyps. The proliferation of nasal polyp epithelial cells was examined by a cell counting kit, and expression of GR-alpha mRNA in nasal polyp epithelial cells was examined by reverse transcription polymerase chain reaction, after training nasal polyp epithelial cells in budesonide solution.

Results

The average survival rate of nasal polyp epithelial cells was the lowest in 1 × 10−6 M budesonide solution (29.284 ± 0.311%), compared with other concentrations. Budesonide at 1 × 10−8 M caused down-regulation of GR-alpha mRNA expression levels at 6 and 12 ours, compared with the 0-hour group (p < 0.001); compared with the 0-hour group, there were significantly lower expression levels of GR-alpha mRNA at both 24 and 48 hours (p < 0.001); Expression of GR-alpha mRNA at either 48 or 12 hours was not significantly different from that at 24 hours.

Conclusion

Budesonide can significantly inhibit the proliferation of nasal polyp epithelial cells, down-regulate the expression of GR-alpha mRNA in nasal polyp epithelial cells with time dependence.
Mometasone Furoate Nasal Spray plus Oxymetazoline Nasal Spray: Short-term Efficacy and Safety in Seasonal Allergic Rhinitis
Authors: Meltzer Eli O. , Bernstein David I. , Prenner Bruce M. , Berger William E. , Shekar Tulin , Teper Ariel A.
Published: March 2013

Background

Allergic rhinitis (AR) and associated congestion adversely affect patients’ lives. The intranasal corticosteroid mometasone furoate nasal spray (MFNS) is effective for AR symptoms including nasal congestion, and the intranasal decongestant oxymetazoline (OXY) is effective against nasal congestion, but the combination has not been fully studied. This study was designed to assess the efficacy of the combination of MFNS and OXY for the relief of seasonal allergic rhinitis (SAR) symptoms.

Methods

This phase 2 controlled clinical trial randomized adolescent and adult subjects (≥12 years; 2-year SAR) to MFNS q.d. (200 μg) + 3 sprays/nostril of OXY 0.05% (MFNS + OXY3); MFNS q.d. + 1 spray/nostril of OXY (MFNS + OXY1); MFNS q.d.; OXY b.i.d.; or placebo for 15 days, with 1-week follow-up. Coprimary end points were change from baseline in morning/evening (A.M./P.M.) instantaneous (NOW) total nasal symptom score (TNSS) over days 1–15 and AUC (AUC[0–4 hr]) change from baseline in day 1 congestion.

Results

In 705 subjects, both combinations reduced A.M./P.M. NOW TNSS over days 1–15 significantly more than OXY b.i.d. or placebo (p ≤ 0.002). Mean standardized AUC(0–4hr) day 1 congestion change from baseline was significantly greater in combination and OXY b.i.d. groups (MFNS + OXY3, −0.92; MFNS + OXY1, −0.80; OXY b.i.d., −1.06) versus placebo (–0.57) and MFNS q.d. (–0.63). Combinations and MFNS q.d. were significantly effective for A.M./P.M. NOW TNSS over each weekly period; OXY b.i.d. was superior to placebo in week 1. Adverse events (AEs) were few and similar across treatments; one MFNS q.d. and one placebo subject experienced a serious AE, with neither considered treatment related.

Conclusion

Combining MFNS with OXY relieves SAR symptoms, including congestion, with faster onset of action than MFNS q.d. and better sustained efficacy than OXY b.i.d.
Nasal Provocation Test Using Allergen Extract versus Cold Dry Air Provocation Test: Which and When?
Authors: Kim Young Hyo , Jang Tae Young
Published: March 2013

Background

Nasal provocation tests (NPTs) are useful for evaluation of patients with allergic rhinitis. The cold dry air (CDA) provocation test is useful for evaluation of patients with nonspecific nasal hyperreactivity (NHR). This study aimed to determine whether the NPT or CDA provocation would be more useful for patients with different clinical pictures.

Methods

We evaluated changes in nasal symptoms (visual analog scale [VAS]) and acoustic parameters after NPT or CDA provocation in healthy volunteers (group A, n = 27), patients with allergic rhinitis (group B, n = 20), and subjects with nonallergic rhinitis (group C, n = 26). According to their subjective cold hyperresponsiveness (SCH), we compared changes in VAS and acoustic parameters after each protocol. The correlation between results of the skin-prick test (SPT) and changes in VAS after each protocol was analyzed. Finally, we performed an analysis of correlation between NPT and CDA provocation.

Results

After NPT, group B showed a larger change in VAS for rhinorrhea, sneezing, and itching (p < 0.01). After CDA challenge, the change in VAS for nasal obstruction was larger in group C (p < 0.05). Changes in acoustic parameters were larger in groups B and C after NPT (p < 0.01). After CDA challenge, the SCH+ group (n = 49) showed a larger decrease of acoustic parameters than the SCH– group (n = 24; p < 0.01). Significant correlation was observed between the size of SPT and degree of change in VAS after NPT. No significant correlation was observed between NPT and CDA.

Conclusion

CDA could be an adjunct tool for evaluating NHR in patients with self-reported SCH.
Nasal Eosinophilia and Serum Soluble Intercellular Adhesion Molecule 1 in Patients with Allergic Rhinitis Treated with Montelukast Alone or in Combination with Desloratadine or Levocetirizine
Authors: Ciebiada Maciej , Barylski Marcin , Ciebiada Malgorzata Gorska
Published: March 2013

Background

Because intercellular adhesion molecule (ICAM) 1 and recruitment of eosinophils are crucial in supporting allergic inflammation, their down-regulation may bring additional benefits in patients’ recovery. We have assessed nasal eosinophilia and serum soluble ICAM-1 (sICAM-1) concentrations in relation to nasal symptoms in patients with persistent allergic rhinitis (AR) treated for 6 weeks with either desloratadine, levocetirizine, montelukast alone, or in combination.

Methods

In this single-center, randomized, double-blind, placebo-controlled, crossover, two-arm study, 40 patients with persistent AR were randomized to receive either montelukast and/or levocetirizine or placebo (n = 20) or to receive treatment with montelukast and/or desloratadine or placebo (n = 20). Nasal eosinophilia and concentration of sICAM-1 in peripheral blood were assessed before and on the last day of each treatment period.

Results

All active treatments in both arms of the study resulted in the decrease of sICAM-1 and nasal eosinophilia, which correlated with the severity of nasal symptoms. In the montelukast/levocetirizine arm, montelukast decreased nasal eosinophilia more significantly than levocetirizine, whereas in reduction of sICAM-1 all active treatment options were equally effective. However, in the desloratadine/montelukast arm, the resulting improvement of combination therapy of sICAM-1 and the influx of eosinophils was not statistically significant.

Conclusion

The improvement of nasal symptoms in patients with AR treated with antihistamines, with or without montelukast, may additionally result from the reduction of sICAM-1 and nasal eosinophilia. Because the combination therapy may bring inconclusive benefits in this area there is a strong need of further studies to find mechanisms that favor combination therapy.
The Auricle's Cavum conchae Composite Graft in Nasal Reconstruction
Authors: Scheithauer Marc O. , Rotter Nicole , Lindemann Joerg , Schulz Melanie , Rettinger Gerhard , Veit Johannes A.
Published: March 2013

Background

Autologous transplants consisting of skin and cartilage, so-called composite grafts (CGs), are useful in nasal reconstruction of multilayered defects. A CG from the auricle's cavum conchae serves both functional and esthetic demands. This article outlines the indications and the requirements of the CG, making special considerations to improve wound healing, and discusses our results in consideration with recent publications.

Methods

A retrospective case–control study assessing the functional and esthetic long-term results in the donor and recipient site is presented.

Results

Between 2005 and 2011, 91 patients received differently sized CGs of the auricle for nasal reconstruction. In 85/91 cases the donor site defect was closed using a retroauricular pedicled island flap. Six of 91 defects were closed primarily. Indications were multilayered defects of the nasal vestibule, the nasal floor, the inner nasal valve, and the lateral sidewall. The main indication for surgery was skin malignancies. One of 91 major and 14/91 minor complications were observed. Seventy-seven of 91 patients received a custom-made prosthesis to prevent stenotic scarring. The 2.5-year follow-up showed excellent results of stability and shape at the donor and recipient site.

Conclusion

The auricular inner lining CG is a versatile and reliable autologous transplant, which is ideal for multilayered nasal reconstruction because of easy harvesting, little donor site morbidity, and its convex shape. Septal splints and custom-made prosthesis secure healing and prevent stenotic scarring.
Evaluation of a Polysaccharide Gel for Laser-assisted Skull Base Repair
Authors: Bleier Benjamin S. , Palmer James N. , Cohen Noam A.
Published: March 2013

Background

Endoscopic reconstruction of skull base defects remains a challenge. Laser tissue welding (LTW) is a technique in which a laser-activated solder is used to create instantaneous repairs of skull base defects with burst strengths far exceeding intracranial pressure (ICP). This study was designed to define the thermal and inflammatory profile of a novel polysaccharide soldering gel, to assess the burst strength of the repair, and to determine the time required for solder resorption.

Methods

A prospective study was performed in rabbit and mouse models. Ten dorsal rabbit maxillary sinusotomies were laser welded and burst pressure thresholds were compared with control wounds on postoperative days (PODs) 0 and 5. All welds were examined histologically on PODs 0, 5, and 45 for thermal injury, inflammation, and degree of solder resorption. In mice, dura was exposed and laser welding was performed (n = 2). Results were compared histologically with dura exposed to laser energy alone (n = 2) on POD 7.

Results

The burst pressures of the rabbit LTW group were significantly higher than control on PODs 0 (135.0 mmHg and SD = 5.8 versus 8.0 mmHg and SD = 0.5; n = 4) and 5 (155.4 mmHg and SD = 2.9 versus 41.7 mmHg and SD = 7.3; n = 4; p < 0.05). No significant thermal or inflammatory effect was found in any of the rabbit or mouse welds. Complete solder resorption was noted by POD 45.

Conclusion

LTW using a polysaccharide gel is capable of creating mucosal repairs capable of withstanding over four times normal ICP without additional grafting materials. These repairs increase in strength over time, have no thermal or inflammatory sequelae, and establish complete solder resorption within 45 days.
Computational Comparison of CPDT to other Conjugated Linkers in Triarylamine-based Organic Dyes
Authors: Climent Clàudia , Casanova David
Published: March 2013

The use of the cyclopentadithiophene (cpdt) fragment to chemically link electron donor and acceptor groups has become a rather common procedure to design new organic dyes with enhanced light harvesting properties. The photo-to-current efficiencies obtained by sensitized solar
cells with dyes incorporating the cpdt moiety are commonly improved with respect to other similar ?-fragments as separators. In many cases, the advantages of cpdt can be related to the larger extinction coefficients obtained. In this work we perform a detailed computational
study of triarylamine-based organic dyes with the cyanoacrylic acid as the acceptor group and considering a variety of conjugated linkers with cpdt as the reference case. The influence of slightly different linkers and donor groups in the computed excitation energies and oscillator
strengths is discussed by means of molecular geometries and frontier orbitals. The structural characteristics imposed by cpdt compared to similar conjugated bridges are responsible for its larger computed oscillator strengths. The insertion of an ethylene unit between the donor group
and the linker systematically reduces the energy gap to the first excited singlet state and yields larger oscillator strengths of the optical transition. These results could be very helpful in the quest of new organic dyes with improved properties as sensitizers in Grätzel cells.
Everything you always wanted to Know about Black Dye (but Were Afraid to Ask): A DFT/TDDFT Investigation
Authors: Fantacci Simona , Lobello Maria G. , De Angelis Filippo
Published: March 2013

We report an exhaustive theoretical and computational investigation of the electronic, optical, redox and acid-base properties, along with the adsorption mode on TiO2, of Black Dye (BD), the prototypical panchromatic dye for solar cell applications. We investigated in detail
the variation of the relevant dye properties as a function of the solution pH, corresponding to the stepwise deprotonation of the carboxylic groups. Our results reproduced the expected blue-shift of the optical absorption spectrum and the experimental trend of oxidation potentials by increasing
pH, which turned both out to be in excellent agreement with experimental values. Also, our calculated excited state oxidation potential is in good agreement with available experimental data. We then looked at the pKa of the various deprotonation steps, finding lowest pKa
values for the stepwise dissociation of three protons of 2.71, 3.69 and 5.20, in excellent agreement with experimental pKa values of 3 and 5, for two and one protons dissociation, respectively. We finally investigated the adsorption of BD on TiO2, finding the most stable
adsorption to occur via two dissociated monodentate carboxylic groups. Inspection of the electronic structure and alignment of energy levels for N719 and BD revealed a reduced driving force for electron injection in the latter dye, which could possibly lead to energetically unfavorable electron
transfer from the excited dye to the TiO2 conduction band. Our results may constitute a reference study for future investigations and optimization of BD-based dye-sensitized solar cells.
Near-infrared Sensitization in Dye-sensitized Solar Cells
Authors: Park Jinhyung , Viscardi Guido , Barolo Claudia , Barbero Nadia
Published: March 2013

Dye-sensitized solar cells (DSCs) are a low cost and colorful promising alternative to standard silicon photovoltaic cells. Though many of the highest efficiencies have been associated with sensitizers absorbing only in the visible portion of the solar radiation, there is a growing
interest for NIR sensitization. This paper reviews the efforts made so far to find sensitizers able to absorb efficiently in the far-red NIR region of solar light. Panchromatic sensitizers as well as dyes absorbing mainly in the 650–920 nm region have been considered.
One-dimensional and (001) Facetted Nanostructured TiO2 Photoanodes for Dye-sensitized Solar Cells
Authors: Lin Hong , Wang Xiao , Hao Feng
Published: March 2013

As one of the most important components in dye-sensitized solar cells (DSCs), photoanode materials have attracted massive interest and been greatly developed through the efforts of various research institutions in recent years. Photoanode materials not only provide a large surface for
the sensitizer to favor charge separation, but also conduct the electrons to the collection electrode. In recent years, one-dimensional (1D) nanostructures (nanotubes (NT), nanowires (NW) and nanorods(NR)), which offer direct pathways for electron transport, and nanostructures (nanosheets
(NS) and nanoparticles (NP)) with (001) crystal facets which possess higher surface energies have been widely employed as photoanode materials. In this review, the progress of 1D nanostructures and those with (001) crystal facets, as well as their photovoltaic performance in DSCs will be discussed
briefly. Further efforts are needed to provide theoretical research for 1D and (001) facet nanostructured TiO2 and to improve DSC performances based on these photoanodes.
Dye-sensitized Solar Cells Employing a SnO2-TiO2 Core-shell Structure Made by Atomic Layer Deposition
Authors: Karlsson Martin , Jõgi Indrek , Eriksson Susanna K. , Rensmo Håkan , Boman Mats , Boschloo Gerrit , Hagfeldt Anders
Published: March 2013

This paper describes the synthesis and characterization of core-shell structures, based on SnO2 and TiO2, for use in dye-sensitized solar cells (DSC). Atomic layer deposition is employed to control and vary the thickness of the TiO2 shell. Increasing
the TiO2 shell thickness to 2 nm improved the device performance of liquid electrolyte-based DSC from 0.7% to 3.5%. The increase in efficiency originates from a higher open-circuit potential and a higher short-circuit current, as well as from an improvement in the electron lifetime.
SnO2-TiO2 core-shell DSC devices retain their photovoltage in darkness for longer than 500 seconds, demonstrating that the electrons are contained in the core material. Finally core-shell structures were used for solid-state DSC applications using the hole transporting
material 2,2',7,7',-tetrakis(N, N-di-p-methoxyphenyl-amine)-9,9',-spirofluorene. Similar improvements in device performance were obtained for solid-state DSC devices.
The Application of Electrospun Titania Nanofibers in Dye-sensitized Solar Cells
Authors: Krysova Hana , Zukal Arnost , Trckova-Barakova Jana , Chandiran Aravind Kumar , Nazeeruddin Mohammad Khaja , Grätzel Michael , Kavan Ladislav
Published: March 2013

Titania nanofibers were fabricated using the industrial NanospiderTM technology. The preparative protocol was optimized by screening various precursor materials to get pure anatase nanofibers. Composite films were prepared by mixing a commercial paste of nanocrystalline anatase
particles with the electrospun nanofibers, which were shortened by milling. The composite films were sensitized by Ru-bipyridine dye (coded C106) and the solar conversion efficiency was tested in a dye-sensitized solar cell filled with iodide-based electrolyte solution (coded Z960). The solar
conversion efficiency of a solar cell with the optimized composite electrode (? = 7.53% at AM 1.5 irradiation) outperforms that of a solar cell with pure nanoparticle film (? = 5.44%). Still larger improvement was found for lower light intensities. At 10% sun illumination, the best
composite electrode showed ? = 7.04%, referenced to that of pure nanoparticle film (? = 4.69%). There are non-monotonic relations between the film's surface area, dye sorption capacity and solar performance of nanofiber-containing composite films, but the beneficial effect of the nanofiber
morphology for enhancement of the solar efficiency has been demonstrated.
Solar-to-Chemical Energy Conversion with Photoelectrochemical Tandem Cells
Authors: Sivula Kevin
Published: March 2013

Efficiently and inexpensively converting solar energy into chemical fuels is an important goal towards a sustainable energy economy. An integrated tandem cell approach could reasonably convert over 20% of the sun's energy directly into chemical fuels like H2 via water splitting.
Many different systems have been investigated using various combinations of photovoltaic cells and photoelectrodes, but in order to be economically competitive with the production of H2 from fossil fuels, a practical water splitting tandem cell must optimize cost, longevity and
performance. In this short review, the practical aspects of solar fuel production are considered from the perspective of a semiconductor-based tandem cell and the latest advances with a very promising technology – metal oxide photoelectrochemical tandem cells – are presented.
Perovskite-related Oxynitrides in Photocatalysis
Authors: Pokrant Simone , Maegli Alexandra E. , Chiarello Gian Luca , Weidenkaff Anke
Published: March 2013

Over the last decades photocatalytic water splitting has become of increasing importance for fundamental and applied research, since the direct conversion of sunlight into chemical energy via the production of H2 has the potential to contribute to the world's energy needs
without CO2 generation. One of the unsolved challenges consists of finding a highly efficient photocatalyst that is cheap, environmentally friendly, contains exclusively abundant elements, is (photo)chemically stable and absorbs visible light. Photocatalytic efficiency is closely
connected to both structural properties like crystallinity, particle size and surface area and to electronic properties like the band gap and the quantum efficiency. Hence extensive control over a large parameter field is necessary to design a good photocatalyst. A material class where the
structure-composition-property relations and the influence of substitution effects are well studied is the perovskite-type family of compounds. The perovskite-related oxynitrides belong to this very flexible compound family where many of the necessary characteristics for a photocatalyst are
already given and some of the intrinsic properties like the band gap can be tuned within the same crystal structure by substitution. In this work we present materials' design concepts to improve the photocatalytic efficiency of a perovskite-type catalyst and describe their effects on the photocatalytic
activity.
From 1e-4 m2 to 2e+4 m2 and Beyond: The Long Road from Lab to Manufacturing
Authors: Meschter John
Published: March 2013

So just how, exactly, does one take something that works in a lab and turn it into a mass produced, globally marketed product? What could be done better to make the whole process more efficient at delivering 'lab marvel' into 'everyday utility'? What are the skill-sets of the people
who do this kind of manufacturing development? How are those skill-sets complementary to and synergistic with the skills of scientists in academia? What is the best marriage of these diverse kinds of people to deliver results quickly and consistently? This article will discuss the steps from
lab to manufacturing and the pitfalls and opportunities that can make the difference between success and failure.
Stained Glass Solar Windows for the Swiss Tech Convention Center
Authors: Barraud Emmanuel
Published: March 2013

As a world first, 300 m² of dye-sensitized solar cells will be integrated into the facade of the EPFL's Convention Center. This prototype will constitute the first application of such technology to a public building. The translucent panels are constructed and assembled by local
small and medium businesses and make use of an invention by EPFL researcher Michael Grätzel. This project is embedded within the framework of the partnership established in 2009 between EPFL and Romande Energie – whose aim is to create one of the largest solar energy parks in Switzerland.
Antisense RNA Regulation and Application in the Development of Novel Antibiotics to Combat Multidrug Resistant Bacteria
Authors: Ji Yinduo , Lei Ting
Published: March 2013

Despite the availability of antibiotics and vaccines, infectious diseases remain one of most dangerous threats to humans and animals. The overuse and misuse of antibacterial agents have led to the emergence of multidrug resistant bacterial pathogens. Bacterial cells are often resilient enough to survive in even the most extreme environments. To do so, the organisms have evolved different mechanisms, including a variety of two-component signal transduction systems, which allow the bacteria to sense the surrounding environment and regulate gene expression in order to adapt and respond to environmental stimuli. In addition, some bacteria evolve resistance to antibacterial agents while many bacterial cells are able to acquire resistance genes from other bacterial species to enable them to survive in the presence of toxic antimicrobial agents. The crisis of antimicrobial resistance is an unremitting menace to human health and a burden on public health. The rapid increase in antimicrobial resistant organisms and limited options for development of new classes of antibiotics heighten the urgent need to develop novel potent antibacterial therapeutics in order to combat multidrug resistant infections. In this review, we introduce the regulatory mechanisms of antisense RNA and significant applications of regulated antisense RNA interference technology in early drug discovery. This includes the identification and evaluation of drug targets in vitro and in vivo, the determination of mode of action for antibiotics and new antibacterial agents, as well as the development of peptide-nucleic acid conjugates as novel antibacterials.
Finding Research Information on the Web: How to Make the Most of Google and Other Free Search Tools
Authors: Blakeman Karen
Published: March 2013

The Internet and the World Wide Web has had a major impact on the accessibility of research information. The move towards open access and development of institutional repositories has resulted in increasing amounts of information being made available free of charge. Many of these resources are not included in conventional subscription databases and Google is not always the best way to ensure that one is picking up all relevant material on a topic. This article will look at how Google's search engine works, how to use Google more effectively for identifying research information, alternatives to Google and will review some of the specialist tools that have evolved to cope with the diverse forms of information that now exist in electronic form.
Spectral and Structural Study of two Piperazine Based Nitrate Salts
Authors: Hakimi Mohammad , Mardani Zahra , Moeini Keyvan
Published: March 2013

Two new compounds, N-(2-aminoethyl)piperazinium trinitrate (AEPH3(NO3)3) and N-(2-hydroxyethyl)piperazinium dinitrate (HEPH2(NO3)2), were prepared. IR spectra of AEPH3(NO3)3 and HEPH2(NO3)2 were compared with those of the parent N-(2-aminoethyl)piperazine (AEP) and N-(2-hydroxyethyl)piperazine (HEP), respectively. The intermolecular interactions affect the symmetry of the nitrate ions in AEPH3(NO3)3 and HEPH2(NO3)2, lowering it from D3h to C2v or Cs. Single-crystal X-ray diffraction of AEPH3(NO3)3 showed that the piperazine moiety has a chair conformation and that two of its nitrogen atoms have a distorted tetrahedral geometry. Similar results were observed for HEPH2(NO3)2. In the crystals, there are N···O contacts between nitrate groups and hydrogen bond motifs between nitrate and ammonium groups (only in AEPH3(NO3)3).
Two Ni(II) Coordination Polymers Constructed with a Bent Connector: Crystal Structures and Magnetic Properties
Authors: Wu MeiChun , Li HaiYe , Huang FuPing
Published: March 2013

The hydrothermal reactions of a bent ligand, 1H-3,5-bis(4-pyridyl)-1,2,4-triazole (bpt), with Ni(II) ions as well as two carboxylate co-ligands yielded two new Ni(II) coordination polymers, {[Ni2(bptc)(bpt)2(H2O)2]·9H2O}n and [Ni(hb)2(bpt)2(H2O)]n (H4bptc = 3,3’,4,4′-benzophenone-tetracarboxylate acid, Hhb = p-Hydroxybenzoate acid). In the first complex, bptc acts as a μ4-bridge to link metal centres, forming a two-dimensional (2-D) layer architecture. The 2-D layer is further connected by bpt pillars to generate a 3-D non-interpenetrating open framework with a 4-connected 64.82 topology. A magnetic study revealed the occurrence of a weak ferromagnetic interaction within the Ni(II) centres. In the second complex, adjacent metal centres are connected by water molecules to furnish a metal–water chain, in which hb and bpt are both terminal ligands.
Synthesis and Crystal Structures of Transition metal(II) Coordination Polymers Constructed by Flexible Sebacic Acid
Authors: Guan Quan-Yin , Shi Pei , Shen Jin-Bei , Xian Hui-Duo , Zhao Guo-Liang
Published: March 2013

Two transition metal(II) coordination polymers [Mn(C10H16O4)(H2O)3]n, and [Co(C10H16O4)(H2O)2]n (C10H16O4 = sebacic dianion), have been synthesised and shown by X-ray crystal structure analyses to have six coordinated, distorted octahedron geometry. In the manganese complex, the metal is coordinated by three oxygen atoms from three sebacic anions and three oxygen atoms of three coordination water molecules, thereby forming a one-dimensional network structure. The cobalt complex is a two-dimensional coordination polymer constructed from mononuclear units in which the metal is coordinated by four oxygen atoms from three sebacic anions and two oxygen atoms from two coordinated water molecules.
Synthesis and Tautomeric Structure of 3,7-bis(arylazo)-2,6-dimethyl-1H-imidazo[1,2-b]pyrazoles
Authors: Shawali Ahmad Sami , Abdallah Magda A. , Shehata Mohamed R. , Kandil Mohamed
Published: March 2013

Three series of 3,7-bis(arylazo)-2,6-dimethyl-1 H-imidazo[1,2- b]pyrazoles were prepared starting from N-aryl-2-oxo-propanehydrazonoyl chlorides. The acid dissociation constants p Ka were determined and correlated with the Hammett equation. The results of such correlations together with the spectroscopic data indicated that the title compounds exist predominantly in the 1 H-bis(arylazo) form.
The Photochemical Synthesis of N-arylacetyl Lactams
Authors: Jiang Lei , Ma Nan , Qiu Jun , Zhang Ronghua
Published: March 2013

The photochemical formation is described of N-arylacetyl lactams from the corresponding N-phenylglyoxylic acid derivatives of pyrrolidine and piperidine-2-carboxylic acids in an acetone:water mixture containing potassium carbonate. Evidence is presented for the possible formation and cleavage of a cyclic ether during this process which leads to the 1, 4-transfer of a carbonyl group.
One-pot Synthesis of 1,3-dinitroalkanes Catalysed by Nickel Species
Authors: Gao Min , Wei Yu-Ping
Published: March 2013

The reaction of aromatic aldehydes with nitromethane afforded a one-pot preparation of 1,3-dinitroalkanes in the presence of a nickel catalytic system. This efficient and simple method proceeded with moderate to high yields (56–99%) under mild conditions.
Three-component Reaction between Ethyl N-(4-oxo-2-thioxothiazolidin-3-yl) Oxalamate and Acetylenic Esters in the Presence of Triphenylphosphine
Authors: Hassanabadi Alireza
Published: March 2013

N-aminorhodanine reacts with ethyl chlorooxoacetate in ethanol to produce ethyl N-(4-oxo-2-thioxothiazolidin-3-yl)oxalamate in nearly quantitative yield. Reaction between this adduct and electron-deficient acetylenic esters in the presence of triphenylphosphine leads to dialkyl 4-ethoxy-5-oxo-1-(4-oxo-2-thioxothiazolidin-3-yl)-2,5-dihydro-1 H-pyrrole-2,3-dicarboxylate derivatives in good yields.
Multicomponent Synthesis of 1-[aryl(p-tolylsulfanyl)methyl]naphthalen-2-ols Using p-toluenesulfonic Acid as a Catalyst
Authors: Hassanabadi Alireza
Published: March 2013

Three-component reaction between 2-naphthol, an aromatic aldehyde and thiols catalysed by p-toluene sulfonic acid ( p-TSA) provided a simple and efficient one-pot route for the synthesis of 1-[aryl(arylsulfanyl)methyl]naphthalen-2-ol derivatives in excellent yields.
The Discovery of a Facile Access to the Synthesis of NSAID Dendritic Prodrugs
Authors: Du Zuyin , Lu Yanhui , Dai Xuedong , Zhang-Negrerie Daisy , Gao Qingzhi
Published: March 2013

An efficient and straightforward method for the preparation of dendritic prodrugs is reported. Based on this new approach, a class of biodegradable dendrimers has been synthesised from L-tartaric acid and one of the nonsteroidal anti-inflammatory drugs, namely, aspirin or ibuprofen.
Synthesis of NO–NSAID Dendritic Prodrugs via Passerini Reaction: New Approach to the Design of Dendrimer-drug Conjugates
Authors: Du Zuyin , Lu Yanhui , Dai Xuedong , Zhang-Negrerie Daisy , Gao Qingzhi
Published: March 2013

We report the synthesis of a novel class of dendritic prodrugs via Passerini reaction in one pot. Such dendrimers feature a simultaneous attachment of a conventional non-steroidal anti-inflammatory drug (NSAID) (such as ibuprofen and aspirin) and a nitric oxide (NO)-releasing moiety (such as an organic nitrate) onto their surface, and are therefore regarded as new drug delivery systems for NO-releasing NSAIDs (NO–NSAIDs).
A Novel Method for the Conversion of Carboxylic Acids to N,N-dimethylamides Using N,N-dimethylacetamide as a Dimethylamine Source
Authors: Aavula Sanjeev Kumar , Chikkulapally Anil , Hanumanthappa N. , Jyothi Indira , Kumar C.H. Vinod , Manjunatha Sulur G. , Sythana Suresh Kumar
Published: March 2013

A simple, cost effective and environmentally benign method is reported for the preparation of N,N-dimethylamides from carboxylic acids. The versatility of the method is determined by synthesising a large number of N,N-dimethyl-amide derivatives. Carboxylic acids are heated at 160–165 °C in N,N-dimethylacetamide solvent in the presence of 1,1′-carbonyldiimidazole to afford the corresponding N,N-dimethylamides in good to excellent yields.
Use of Ester Formylhydrazones for the Synthesis of 1,2,4-triazole and 1,3,4-oxadiazole Derivatives
Authors: Yildirim Nuri , Bekircan Olcay
Published: March 2013

A series of ester formylhydrazones were synthesised by the reaction of alkyl imidate hydrochlorides with formyl-hydrazine. Treatment of the ester formylhydrazones with acetic acid hydrazide, isonicotinic acid hydrazide, nicotinic acid hydrazide, and 4-hydroxybenzhydrazide resulted in the formation of either 4-acylamino-4H-1,2,4-triazoles or 2,5-disubstituted 1,3,4-oxadiazoles. 3-Alkyl-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones were synthesised by the reaction of the ester formylhydrazones with carbohydrazide. Some arylidenamino compounds were synthesised by the reaction of 4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones with several aldehydes. These compounds were characterised by elemental analyses, IR, 1H NMR, and UV spectral techniques.
Efficient Microwave Assisted Synthesis of Some New Benzimidazoles Containing the Mebendazole Nucleus
Authors: Menteşe Emre
Published: March 2013

A simple and practical method has been developed for the synthesis of benzimidazoles containing the biological active mebendazole nucleus. Iminoester hydrochlorides of phenylacetic acids were used as intermediates in the reaction with 3,4-diaminobenzophenone under microwave irradiation leading to the products in good yields and in short reaction times.
Synthesis of Silica Supported Perchloric Acid Nanoparticles (HClO4–SiO2 NPs): Efficient Synthesis of Biscoumarin Derivatives in Water
Authors: Sadeghi Bahareh
Published: March 2013

Reaction between aromatic aldehydes or phenylglyoxals and 4-hydroxycoumarin catalysed by silica supported perchloric acid nanoparticles (HClO4–SiO2 NPs) in water at reflux provided a simple and efficient route for the synthesis of biscoumarin derivatives in high yields.
Gold-catalysed Homocoupling of Alkynes
Authors: Yao Peng
Published: March 2013

The homocoupling reaction of alkynes was carried out in the presence of 10 mol% AuCl3 using I2 as oxidant to generate 1,3-diynes products in high yield. The method is simple, safe and efficient. Both aryl and alkyl substituted alkynyl substrates reacted smoothly. AuClPPh3 also showed comparable catalytic activity to this transformation under a nitrogen atmosphere.
Synthesis, Crystal Structure and Fe3+ Recognition of Novel Triazolethione Schiff Base Derivatives
Authors: Yu Jing-Wen , Wang Yong , Wang Yu-Bo , Wang Chun-Feng
Published: March 2013

Triazolethione Schiff base derivatives have been synthesised from 3-(3-methyl- 4-amino-5-sulfanylidene-4,5-dihydro-1H-1,2,4-triazol-1-yl)-1,3-diphenylpropan-1-one with aromatic aldehydes (ArCHO) and an X-ray single crystal structure for Ar=Ph has been determined. UV-Vis and fluorescence spectral data indicate that the Schiff base where Ar=2-hydroxynaphthyl can recognise selectively Fe3+ and a 1:1 stoichiometric complex is formed between the receptor and the cation.