bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Extraction Sites for Evidence of Retained Tooth Roots and Periapical Pathology*
Authors: Moore James I. , Niemiec Brook
Published: January 2014

The objective of this retrospective clinical study was to determine the frequency and pathogenicity of unintentional retained tooth root fragments after extraction of the maxillary fourth premolar (108 and 208) and mandibular first molar teeth (309 and 409) in 74 canine and 42 feline client-owned patients. Radiographs of client-owned animals with historical evidence of extraction of teeth 309 and 409 were reviewed. All patients had dental extraction(s) for clinical reasons, and all extractions were deemed successful by the practitioners. Extraction sites were radiographed to identify tooth root fragments and pathology. Twenty-five canine and 25 feline patients that had extractions utilizing preoperative and postoperative radiography were also included. Sixty-one of 74 canine patients (82.4%; P < 0.0001) and 39 of 42 feline patients (92.8%; P < 0.0001) had evidence of retained tooth root fragments. In total, 100 of 116 cases (86.4%; P < 0.0001) had retained tooth root fragments, and periapical pathology was found in 66 of 116 (56.8%; P = 0.000000743) radiographs, including 39 of 74 canine cases (52.7%; P = 0.00002765) and 27 of 42 feline cases (64.3%; P = 0.01589). The control group had no evidence of retained root fragments. Further veterinary dental training and routine use of pre- and postoperative dental radiology are recommended.
Présentation
Authors: Clain Olivier
Published: January 2014

Dans un contexte marqué par la propagation de l’onde de choc de la crise économique et les puissantes mobilisations qui ont suivi un peu partout dans le monde, la lutte des étudiants québécois a puisé une fois de plus à la tradition qui singularise le Québec en Amérique du Nord et qui veut que la question de l’accès le plus large possible à l’éducation supérieure y revête une signification collective et éminemment politique. Le texte introduit à ce numéro en rappelant ces quelques points tout en indiquant sommairement comment chacune des explorations sociographiques ici réunies approfondit de façon originale l’interprétation qui s’en déduit. En s’appuyant sur la montée d’un syndicalisme de combat, le mouvement étudiant, qui fut cette fois d’abord ancré dans les humanités, est parvenu à exprimer et à canaliser le mécontentement d’une fraction significative de la société québécoise contre le parti au pouvoir en contestant ses politiques économiques, en particulier celles qui touchent à l’exploitation des ressources naturelles. Mais son succès même a suscité des réactions passionnées, dans les médias, au Québec d’abord et au Canada-anglais aussi bien. 2012, au Québec, ce fut bien décidément l’année des carrés rouges.
Le printemps contre l’hégémonie
Authors: Martin Éric
Published: January 2014

À partir d’entrevues avec des protagonistes du mouvement étudiant, ce texte cherche à identifier les conditions qui ont permis l’émergence d’un mouvement étudiant et populaire d’une ampleur sans précédent lors du printemps 2012. L’émergence d’un pôle étudiant organisé autour du syndicalisme de combat et de la démocratie directe est identifié comme l’un des facteurs importants de consolidation et de persistance du mouvement. Dans un deuxième temps, les revendications en faveur du changement social portées par ce mouvement sont resituées dans le contexte de l’impasse ou du « blocage institutionnel » qui caractérise la société québécoise sous l’empire du néolibéralisme, et qui a pour effet de neutraliser les tentatives d’objectiver de nouvelles formes institutionnelles traversées par des finalités de justice sociale.
Tout voir et tout entendre, mais sans comprendre !
Authors: Sauvageau Florian , Thibault Simon
Published: January 2014

Sans surprise, le conflit étudiant du printemps 2012 a été abondamment couvert par les médias. Est-ce à dire que les Québécois ont été bien informés ? Rien n’est moins certain. Une étude menée par le Centre d’études sur les médias révèle que si les faits (manifestations, violences, négociations, etc.) étaient bien connus des citoyens interviewés, plusieurs d’entre eux estimaient en savoir peu sur les enjeux de fond, que les médias n’avaient pas clarifié à leur satisfaction. À cet égard, le conflit étudiant semble constituer une autre illustration des difficultés qu’ont les médias traditionnels à offrir « a truthful, comprehensive and intelligent account of the day’s events in a context which gives them meaning », selon les mots de la célèbre Commission on Freedom of the Press de 1947, aux États-Unis. À l’aide d’une analyse de données et de propos recueillis lors de rencontres avec des citoyens et un groupe d’intellectuels québécois, nous analysons le contexte de cette couverture médiatique et les enjeux peu ou mal couverts par les médias québécois. Nous proposons également quelques constats qui pourraient expliquer les difficultés des médias à informer adéquatement le public sur ces enjeux de fond durant le conflit étudiant, ainsi que quelques pistes de solution.
« Les enfants gâtés d’une province parasite. »
Authors: Lacombe Sylvie
Published: January 2014

Notre contribution analyse des articles d’opinion – éditoriaux et chroniques – dans le Toronto Star, le Globe and Mail et le National Post durant les mois de mars à septembre 2012. La perception du Printemps québécois y est, dans l’ensemble, plutôt négative, les revendications des étudiants grévistes restant largement incomprises des éditorialistes et chroniqueurs, qui y voient une défense insensée d’intérêts étroits, un caprice d’enfants déjà choyés du fait de leur situation. Mais commenter les événements qui agitent le Québec au printemps 2012 conduit surtout les commentateurs à juger le « modèle québécois » et à se prononcer sur la différence québécoise dans l’ensemble canadien. Plusieurs chroniqueurs rattachent aussi cette agitation aux désordres que connaissent certains pays européens, notamment la Grèce, pour leur trouver des similitudes. Dans tous les cas, la différence québécoise n’inspire aucune bienveillance : au mieux, elle témoigne de l’inconscience et de l’irrationalité qui imprègnent les politiques publiques dans cette province ; au pire, elle est artificiellement maintenue au détriment de tous les contribuables canadiens. C’est ainsi que les étudiants grévistes apparaissent comme les enfants gâtés d’une province parasite.
Influence of mass contrast in alloy phonon scattering
Authors: Shiga Takuma , Hori Takuma , Shiomi Junichiro
Published: January 2014

We have investigated the effect of mass contrast on alloy phonon scattering in mass-substituted Lennard-Jones crystals. By calculating the mass-difference phonon scattering rate using a modal analysis method based on molecular dynamics, we have identified the applicability and limits of the widely used mass-difference perturbation model in terms of the magnitude and sign of the mass difference. The result of a phonon-mode-dependent analysis reveals that the critical phonon frequency, above which the mass-difference perturbation theory fails, decreases with increasing magnitude of the mass difference independently of its sign. This gives rise to a critical mass contrast, above which the mass-difference perturbation model noticeably underestimates the lattice thermal conductivity.
Enhanced red photoluminescence of samarium in zeolite A by interaction with silver ions
Authors: gui Sa chu rong , Imakita Kenji , Fujii Minoru , Hayashi Shinji
Published: January 2014

Photosensitization of samarium (Sm) ions by silver (Ag) ions was achieved by simultaneously doping Sm and Ag in zeolite A cages. Photoluminescence (PL) from the 4G2/5 → 6H2/7 transition of Sm ions at 600 nm was found to be more than 30 times enhanced by the presence of Ag ions. The excitation wavelength dependence of the PL intensity coincided well with the absorption spectra of Ag ions in the ultraviolet region, indicating that Sm ions are excited by the energy transfer from Ag ions.
Pathologic and Clinical Characteristics of Elderly Patients With Breast Cancer: A Retrospective Analysis of a Multicenter Study (Anatolian Society of Medical Oncology)
Authors: İnal Ali , Akman Tulay , Yaman Sebnem , Ozturk Selcuk Cemil , Geredeli Caglayan , Bilici Mehmet , İnanc Mevlude , Harputoglu Hakan , Demirci Umut , Balakan Ozan , Cınkır Havva Yesil , Alıcı Suleyman , Colak Dilsen , Sonmez Ozlem Uysal , Goksel Gamze , Dogu Gamze Gokoz , Engin Huseyin , Unal Olcun Umit , Tamozlu Tulay , Buyukberber Suleyman , Boruban Cem Melih , Isıkdogan Abdurrahman
Published: January 2014

There is very little information about breast cancer characteristics, treatment choices, and survival among elderly patients. The purpose of this multicenter retrospective study was to examine the clinical, pathologic, and biologic characteristics of 620 breast cancer patients age 70 years or older. Between June 1991 and May 2012, 620 patients with breast cancer, recruited from 16 institutions, were enrolled in the retrospective study. Patients had smaller tumors at diagnosis; only 15% of patients had tumors larger than 5 cm. The number of patients who had no axillary lymph node involvement was 203 (32.7%). Ninety-three patients (15.0%) had metastatic disease at diagnosis. Patients were characterized by a higher fraction of pure lobular carcinomas (75.3%). The tumors of the elderly patients were also more frequently estrogen receptor (ER) positive (75.2%) and progesterone receptor (PR) positive (67.3%). The local and systemic therapies for breast cancer differed according to age. An association between age and overall survival has not been demonstrated in elderly patients with breast cancer. In conclusion, the biologic behavior of older patients with breast cancer differs from younger patients, and older patients receive different treatments.
Duplicated Gallbladder
Authors: Shiba Hiroaki , Misawa Takeyuki , Ito Ryusuke , Ohki Kazuyoshi , Igarashi Takao , Yanaga Katsuhiko
Published: January 2014

Duplication of the gallbladder is a rare congenital anomaly of the biliary system with the incidence of 1 in 3800. A 38-year-old woman visited our patient clinic for evaluation of wall thickening of the gallbladder, detected by abdominal ultrasonography during a regular medical checkup. Drip infusion cholecystocholangiography–computed tomography revealed Y-shaped duplicated gallbladders.
Metachronous Multiple Primary Malignant Neoplasms of the Stomach and the Breast: Report of Two Cases With Review of Literature
Authors: Karthikeyan Vilvapathy Senguttuvan , Sistla Sarath Chandra , Srinivasan Ramachandran , Basu Debdatta , Panicker Lakshmi C. , Ali Sheik Manwar , Rajkumar Nagarajan
Published: January 2014

Multiple primary malignant neoplasm is the occurrence of a second primary malignancy in the same patient within 6 months of the detection of first primary (synchronous), or 6 months or more after primary detection (metachronous). Multiple primary malignant neoplasms are not very frequently encountered in clinical practice. The relative risk for a second primary malignancy increases by 1.111-fold every month from the detection of the first primary malignancy in any individual. We present 2 patients treated for carcinoma of the breast who developed a metachronous primary malignancy in the stomach to highlight the rare occurrence of multiple primary malignant neoplasms. These tumors were histologically dissimilar, with distinct immunohistochemical parameters. The importance lies in carefully identifying the second primary malignancies, not dismissing them as metastases, and treating them accordingly.
Retroperitoneal Liposarcoma With Leiomyosarcomatous Differentiation
Authors: Suzuki Masaki , Fukuchi Minoru , Sakurai Shinji , Naitoh Hiroshi , Kiriyama Shinsuke , Fukasawa Takaharu , Tabe Yuichi , Yamauchi Hayato , Yoshida Tomonori , Kuwano Hiroyuki
Published: January 2014

We herein describe a 60-year-old Japanese man with a giant retroperitoneal liposarcoma undergoing leiomyosarcomatous differentiation. He was admitted to our hospital because of a 5-month history of dysphagia and abdominal distention. Abdominal computed tomography showed a giant tumor that occupied the entire retroperitoneal space. The majority of the mass was lipomatous and low density; both a heterogenous and solid mass were also present. A giant retroperitoneal liposarcoma was diagnosed, and tumor resection was performed. At surgery, the tumor was mostly isolated from the retroperitoneum and other organs. Histopathologically, the tumor comprised well-differentiated and dedifferentiated liposarcoma with heterologous differentiation of the leiomyosarcomatous components, which is a rare phenomenon in liposarcoma. The patient was alive 3 years after the first treatment, although he has had 3 local recurrences (approximately one recurrence yearly) and has been treated by repeated resection and radiotherapy.
Early Versus Delayed Laparoscopic Cholecystectomy for Acute Cholecystitis: A Prospective, Randomized Study
Authors: Özkardeş Alper Bilal , Tokaç Mehmet , Dumlu Ersin Gürkan , Bozkurt Birkan , Çiftçi Ahmet Burak , Yetişir Fahri , Kılıç Mehmet
Published: January 2014

We aimed to compare the clinical outcome and cost of early versus delayed laparoscopic cholecystectomy for acute cholecystitis. Sixty patients with acute cholecystitis were randomized into early (within 24 hours of admission) or delayed (after 6–8 weeks of conservative treatment) laparoscopic cholecystectomy groups. There was no significant difference between study groups in terms of operation time and rates for conversion to open cholecystectomy. On the other hand, total hospital stay was longer (5.2 ± 1.40 versus 7.8 ± 1.65 days; P = 0.04) and total costs were higher (2500.97 ± 755.265 versus 3713.47 ± 517.331 Turkish Lira; P = 0.03) in the delayed laparoscopic cholecystectomy group. Intraoperative and postoperative complications were recorded in 8 patients in the early laparoscopic cholecystectomy group, whereas no complications occurred in the delayed laparoscopic cholecystectomy group (P = 0.002). Despite intraoperative and postoperative complications being associated more with early laparoscopic cholecystectomy compared with delayed intervention, early laparoscopic cholecystectomy should be preferred for treatment of acute cholecystitis because of its advantages of shorter hospital stay and lower cost.
Peripancreatic Soft Tissue Involvement: Independent Outcome Predictor in Patients With Resected Pancreatic Adenocarcinoma
Authors: Jahromi Alireza Hamidian , Zibari Gazi B. , Jafarimehr Elnaz , Chu Quyen , Wellman Gregory P. , Shi Runhua , Johnson Lester W. , Shokouh-Amiri Hosein
Published: January 2014

The impact of cancer involving the peripancreatic soft tissue (PST), irrespective of margin status, following a resection of pancreatic adenocarcinoma is not known. The purpose of this study is to determine such an impact on a cohort of patients. Data from 274 patients who underwent pancreatic surgery by our team between 1998 and 2012 was reviewed. Of those 119 patients who had pancreatic resection for adenocarcinoma were retrospectively analyzed. Patients were categorized into 3 groups: Group 1 = R1 resection (N = 39), Group 2 = R0 with involved PST (N = 54), and Group 3 = R0 with uninvolved PST (N = 26). Demographics, operative data, tumor characteristics and overall survival (OS) were evaluated. Operations performed were: Whipple (N = 53), pylorus sparing Whipple (N = 41), total pancreatectomy (N = 11), and other (N = 14). Median OS for Groups 1, 2, and 3 were 8.5 months, 12 months, and 69.6 months respectively (P < 0.001). Tumor size (P = 0.016), margin status (P = 0.006), grade (P = 0.001), stage (P = 0.037), PST status (P < 0.001), complications (P = 0.046), transfusion history (P = 0.003) were all predictors of survival. Cox regression analysis demonstrated that grade (HR = 3.1), PST involvement (HR = 2.7), transfusion requirement (HR = 2.6) and margin status (HR = 2.0) were the only independent predictors of mortality. PST is a novel predictor of poor outcome for patients with resected pancreatic cancer.
Portal Vein Stenting to Treat Portal Vein Stenosis in a Patient With Malignant Tumor and Gastrointestinal Bleeding
Authors: Sakurai Katsunobu , Amano Ryosuke , Yamamoto Akira , Nishida Norifumi , Matsutani Shinya , Hirata Keiichiro , Kimura Kenjiro , Muguruma Kazuya , Toyokawa Takahiro , Kubo Naoshi , Tanaka Hiroaki , Yashiro Masakazu , Ohira Masaichi , Hirakawa Kosei
Published: January 2014

This report describes the successful use of portal venous stent placement for a patient with recurrent melena secondary to jejunal varices that developed after subtotal stomach preserved pancreatoduodenectomy (SSPPD). A 67-year-old man was admitted to our hospital with tarry stool and severe anemia at 2 years after SSPPD for carcinoma of the head of the pancreas. Abdominal computed tomography examination showed severe stenosis of the extrahepatic portal vein caused by local recurrence and showed an intensely enhanced jejunal wall at the choledochojejunostomy. Gastrointestinal bleeding scintigraphy also revealed active bleeding near the choledochojejunostomy. Based on these findings, jejunal varices resulting from portal vein stenosis were suspected as the cause of the melena. Portal vein stenting and balloon dilation was performed via the ileocecal vein after laparotomy. Coiling of the jejunal varices and sclerotherapy of the dilate postgastric vein with 5% ethanolamine oleate with iopamidol was performed. After portal stent placement, the patient was able to lead a normal life without gastrointestinal hemorrhage. However, he died 7 months later due to liver metastasis.
Safe Transanal Tumor Resection Using a Harmonic Scalpel
Authors: Inoue Yuji , Ohki Takeshi , Nakagawa Ryousuke , Yamamoto Masakazu
Published: January 2014

We performed a safe and simple transanal tumor resection involving total layer resection using a harmonic scalpel as a resecting device. Here we report the results of our experience with this technique between 2005 and 2011. This study involved 32 patients who underwent transanal tumor resection using a harmonic scalpel. The subjects comprised 18 men and 14 women ranging in age from 34 to 87 years (mean: 64.5 years). The tumors measured 8 to 70 mm (mean: 31 mm) in diameter. The operation took 7 to 86 minutes (mean: 29 minutes), and the amount of bleeding was 0 to 165 mL (mean: 16.2 mL). There was no intraoperative blood loss that necessitated hemostatic procedures. Histopathologically, the lesions included hyperplastic polyp in 1 case, adenoma in 9, carcinoma in situ in 7, submucosal invasive cancer in 6, muscularis propria cancer in 4, carcinoid in 1, malignant lymphoma in 1, gastrointestinal stromal tumor in 1, mucosal prolapsed syndrome in 1, and mucosa-associated lymphoid tissue lymphoma in 1. With our technique, en bloc resection was achieved in all patients, and the use of a harmonic scalpel enabled us to complete the operation within 30 minutes, on average, without intraoperative bleeding.
A Rare Case of Granular Cell Tumor of the Anal Region: Diagnostic Difficulty to Masses in the Anal Area
Authors: Fujii Takaaki , Morita Hiroki , Yamaguchi Satoru , Tsutsumi Soichi , Asao Takayuki , Kuwano Hiroyuki
Published: January 2014

Granular cell tumor may be located anywhere in the body; however, the gastrointestinal tract is infrequently involved and anal granular cell tumors are extremely rare. We report herein a rare case of granular cell tumor in the anal region. In the current case, a 66-year-old Japanese woman was found to have a polypoid lesion in the anus with hemorrhoids. The mass detected as an anal polypoid lesion with ulceration was resected and diagnosed as granular cell tumor by histologic examination. Granular cell tumor of the anal region is rare, and benign perianal polypoid lesions are relatively uncommon clinical findings. They might present diagnostic challenges to surgeons and pathologists. Awareness of the differential diagnosis of granular cell tumor and careful microscopic examination might allow proper management and diagnosis.
Seminal Vesicle-Rectal Fistula Secondary to Anastomotic Leakage After Low Anterior Resection for Rectal Cancer: A Case Report and Brief Literature Review
Authors: Kitazawa Masato , Hiraguri Manabu , Maeda Chika , Yoshiki Mizukami , Horigome Naoto , Kaneko Gengo
Published: January 2014

We report a case of a patient with seminal vesicle-rectal fistula, an extremely rare complication of low anterior resection of the rectum. A 53-year-old man with rectal adenocarcinoma underwent low anterior resection in our hospital. The patient experienced diarrhea, pneumaturia, and low-grade fever on postoperative day 13. A computed tomography scan showed emphysema in the right seminal vesicle. We concluded that anastomotic leakage induced a seminal vesicle-rectal fistula. The patient underwent conservative therapy with total parenteral nutrition and oral intake of metronidazole. Diarrhea and pneumaturia rapidly improved after metronidazole administration and the patient was successfully cured without invasive therapy such as colostomy or surgical drainage. A seminal vesicle-rectal fistula is a rare complication of low anterior resection, and therapeutic strategies for this condition remain elusive. Our report provides valuable information on the successful conservative treatment of a secondary seminal vesicle-rectal fistula that developed after low anterior resection of the rectum in a patient.
Molecular Analysis of Fragile X Syndrome
Authors: Basehore Monica J. , Friez Michael J.
Published: January 2014

The gene responsible for Fragile X syndrome, fragile X mental retardation‐1 (FMR1), contains an unstable sequence of CGG trinucleotide repeats in its promoter region. Expansions of >200 trinucleotide repeats are considered full mutations and typically lead to abnormal methylation of the region, resulting in loss of FMR1 expression. Males with loss of FMR1 protein are expected to be affected by Fragile X syndrome, while females may or may not clinically manifest features of the condition. The protocols in this unit outline the complementary use of polymerase chain reaction (PCR) and methylation‐sensitive Southern blot hybridization to accurately measure trinucleotide repeat size and methylation status. These protocols are also used to evaluate CGG repeat size in two adult‐onset conditions known for their association with FMR1 premutation alleles, Fragile X Tremor/Ataxia (FXTAS) syndrome and Premature Ovarian Failure (POF). Curr. Protoc. Hum. Genet. 80:9.5.1‐9.5.19. © 2014 by John Wiley & Sons, Inc.
Seismicity within a propagating ice shelf rift: The relationship between icequake locations and ice shelf structure
Authors: Heeszel David S. , Fricker Helen A. , Bassis Jeremy N. , O'Neel Shad , Walter Fabian
Published: January 2014

Iceberg calving is a dominant mass loss mechanism for Antarctic ice shelves, second only to basal melting. An important process involved in calving is the initiation and propagation of through‐penetrating fractures called rifts; however, the mechanisms controlling rift propagation remain poorly understood. To investigate the mechanics of ice shelf rifting, we analyzed seismicity associated with a propagating rift tip on the Amery Ice Shelf, using data collected during the austral summers of 2004–2007. We apply a suite of passive seismological techniques including icequake locations, back projection, and moment tensor inversion. We confirm previous results that show ice shelf rifting is characterized by periods of relative quiescence punctuated by swarms of intense seismicity of 1 to 3 h. Even during periods of quiescence, we find significant deformation around the rift tip. Moment tensors, calculated for a subset of the largest icequakes (Mw > −2.0) located near the rift tip, show steeply dipping fault planes, horizontal or shallowly plunging stress orientations, and often have a significant volumetric component. They also reveal that much of the observed seismicity is limited to the upper 50 m of the ice shelf. This suggests a complex system of deformation that involves the propagating rift, the region behind the rift tip, and a system of rift‐transverse crevasses. Small‐scale variations in the mechanical structure of the ice shelf, especially rift‐transverse crevasses and accreted marine ice, play an important role in modulating the rate and location of seismicity associated with the propagating ice shelf rifts.
Densification of polar snow: Measurements, modeling, and implications for altimetry
Authors: Morris E. M. , Wingham D. J.
Published: January 2014

Density profiles in the upper 10–14 m of snow have been measured along a 500 km traverse across the Greenland ice sheet, using a neutron scattering technique. Repeat measurements, over periods ranging from a few days to 5 years, allow strain rates to be determined as a function of depth. Very large strain rates are observed in the surface layer of snow over summer periods. In the underlying multiyear snow, strain rate decreases with decreasing porosity. However, once this effect has been removed, the effect of increasing overburden pressure is counteracted by increasing strength of the material. There are fluctuations in strain rate associated with the annual layering, which indicate that winter and summer snow have different strengths. Based on these observations, we derive a new densification equation which includes the effect of snow density and snow type, and the effect of temperature, described by an Arrhenius expression with activation energy of the order of 110 kJ mol−1 and an exponential prefactor determined simply by the temperature history of the snow. For multiyear snow and meteorological conditions that do not vary from year to year, our equation reduces to a form similar to the Herron and Langway equation for first‐stage densification. Using the new equation, we calculate the sensitivity of compaction rate to short‐term fluctuations in temperature and accumulation as 0.11–0.20 m a−1 K−1 and 0.33–0.95 m a−1(meters water equivalent)−1, respectively, and discuss the consequent uncertainty in satellite measurements of the long‐term elevation trend in this area of the Greenland ice sheet.
A Focus on Environment at High School Students' Fall Meeting Poster Session
Authors: Kumar Mohi
Published: January 2014

With titles like “Correlates of avian building strikes at a glass façade museum surrounded by avian habitat” and “Electrospray ionization FT‐ICR/MS investigation of zinc sulfate clusters,” a series of posters presented at AGU's Fall Meeting on 12 December 2013 might seem like a session covering general contributions from AGU members. However, something was unique about the posters: Most were created and presented by high school students.
Kimball to Be Nominated to Lead USGS
Authors: Showstack Randy
Published: January 2014

Suzette Kimball, who has served as acting director of the U.S. Geological Survey (USGS) since February 2013, will be nominated to be director of the agency, U.S. president Barack Obama announced on 9 January. If Kimball's nomination is confirmed by the U.S. Senate, she will lead the science agency, which has more than 8000 employees and an annual budget of more than $1.1 billion.
Click Chemistry in Materials Science
Authors: Xi Weixian , Scott Timothy F. , Kloxin Christopher J. , Bowman Christopher N.
Published: January 2014

Despite originating only a little more than a decade ago, click chemistry has become one of the most powerful paradigms in materials science, synthesis, and modification. By developing and implementing simple, robust chemistries that do not require difficult separations or harsh conditions, the ability to form, modify, and control the structure of materials on various length scales has become more broadly available to those in the materials science community. As such, click chemistry has seen broad implementation in polymer functionalization, surface modification, block copolymer and dendrimer synthesis, biomaterials fabrication, biofunctionalization, and in many other areas of materials science. Here, the basic reactions, approaches, and applications of click chemistry in materials science are highlighted, and a brief look is taken into the future enabling developments in this field.
Anomalous Photodeposition of Ag on Ferroelectric Surfaces with Below‐Bandgap Excitation
Authors: Seal Katyayani , Rodriguez Brian J. , Ivanov Ilia N. , Kalinin Sergei V.
Published: January 2014

Ferroelectric lithography, a recent method of fabricating functional interfaces, traditionally involves photoreduction on polarized ferroelectric surfaces at optical energies above the bandgap of the ferroelectric. In this work, for the first time, photochemical deposition of elemental Ag nanoparticles on a specifically poled lithium niobate substrate is reported, with a broad white‐light spectrum transmitted through the crystal. The transmitted light has energies only below the bandgap, leading to the conclusion that the Ag reduction proceeds through non‐linear effects, specifically, second harmonic generation.
Polypoid changes of the middle turbinate as an indicator of atopic disease
Authors: White Laura J. , Rotella Melissa R. , DelGaudio John M.
Published: January 2014

Background

High levels of local immunoglobulin E (IgE) have been demonstrated in nasal polypoid tissue; however, an association between nasal polyps and allergy has not been proven. The authors have observed that polypoid edema isolated to the leading edge of the middle turbinate (MT) is highly associated with allergic rhinitis. The objective of this study was to determine if there is an association between isolated MT polyps and inhalant allergy.

Methods

A single institution prospective study was performed. Twenty‐five consecutive patients found to have isolated MT polyps on endoscopic exam were recruited. Nasal and allergy symptoms were documented on the intake form. Allergy testing was recommended to all patients.

Results

Of the 25 patients found to have isolated MT polypoid edema documented on endoscopic exam, 16 patients underwent skin or in vitro allergy testing. All of the patients tested positive for inhalant allergy.

Conclusion

This small series provides strong evidence to support an association between isolated MT polypoid edema and allergy. We recommend allergy testing in all patients with isolated MT polyps or polypoid edema.
Osteitis is a misnomer: a histopathology study in primary chronic rhinosinusitis
Authors: Snidvongs Kornkiat , Earls Peter , Dalgorf Dustin , Sacks Raymond , Pratt Eleanor , Harvey Richard J.
Published: January 2014

Background

The histological features of osteitis in chronic rhinosinusitis (CRS) in animal studies induced by bacterial inoculation into maxillary sinuses revealed inflammatory involvement of the underlying bone matrix and/or the Haversian system; however, human studies do not mention these findings. The objective of this study was to investigate the inflammatory characterization of osteitis in CRS.

Method

A prospective study of primary CRS patients undergoing sinus surgery was conducted (August 2012 to April 2013). Bone‐mucosa samples were taken from a predetermined site that correlated to a computed tomography location. Radiological bone thickness was measured. A blinded histopathological assessment included inflammatory infiltrate of bone, periosteal reaction, presence of osteoblasts or osteoclasts, fibrosis, and the percentage of new woven bone to total bone thickness, together with an overall opinion of whether neo‐osteogenesis was present.

Results

Twenty‐two primary CRS patients (age 45.8 ± 15.6 years; 59.1% female) were recruited. CRS with polyps accounted for 59.1% of patients. The bony thickness measured radiologically was a median 1.72 (interquartile range [IQR], 2.38; range, 0.3‐12.14) mm. No samples (0%) had evidence of inflammatory infiltrate of bone; 90.9% had both osteoblasts present and new woven bone formation. Woven bone was greater with periosteal reaction (80.83% ± 9.25% vs. 47.50% ± 29.37%; p = 0.006), greater with osteoclasts present (80.00% ± 12.58% vs 59.00% ± 28.52%; p = 0.03), and greater when fibrosis was present (69.75% ± 24.14% vs 25.00% ± 7.07%; p = 0.003).

Conclusion

Most primary CRS patients demonstrated evidence of new woven bone formation. True “osteitis” with inflammatory infiltrate of the bone was not observed. “Osteitis” is likely a process of neo‐osteogenesis and bone remodeling, rather than bone inflammation in primary CRS.
Size‐Dependent Phase Transformation of Catalytically Active Nanoparticles Captured In Situ
Authors: Fischer Nico , Clapham Brett , Feltes Theresa , van Steen Eric , Claeys Michael
Published: January 2014

The utilization of metal nanoparticles traverses across disciplines and we continue to explore the intrinsic size‐dependent properties that make them so unique. Ideal nanoparticle formulation to improve a process’s efficiency is classically presented as exposing a greater surface area to volume ratio through decreasing the nanoparticle size. Although, the physiochemical characteristics of the nanoparticles, such as phase, structure, or behavior, may be influenced by the nature of the environment in which the nanoparticles are subjected1, 2 and, in some cases, could potentially lead to unwanted side effects. The degree of this influence on the particle properties can be size‐dependent, which is seldom highlighted in research. Herein we reveal such an effect in an industrially valuable cobalt Fischer–Tropsch synthesis (FTS) catalyst using novel in situ characterization. We expose a direct correlation that exists between the cobalt nanoparticle’s size and a phase transformation, which ultimately leads to catalyst deactivation.
Direct Catalytic Trifluoromethylthiolation of Boronic Acids and Alkynes Employing Electrophilic Shelf‐Stable N‐(trifluoromethylthio)phthalimide
Authors: Pluta Roman , Nikolaienko Pavlo , Rueping Magnus
Published: January 2014

A new and safe method for the synthesis of N‐(trifluoromethylthio)phthalimide, a convenient and shelf‐stable reagent for the direct trifluoromethylthiolation, has been developed. N‐(Trifluoromethylthio)phthalimide can be used as an electrophilic source of F3CS+ and reacts readily with boronic acids and alkynes under copper catalysis. The utility of CF3S‐containing molecules as biologically active agents, the mild reaction conditions employed, and the high tolerance of functional groups demonstrate the potential of this new methodology to be widely applied in organic synthesis as well as industrial pharmaceutical and agrochemical research and development.
Dipole‐Induced Band‐Gap Reduction in an Inorganic Cage
Authors: Lv Yaokang , Cheng Jun , Steiner Alexander , Gan Lihua , Wright Dominic S.
Published: January 2014

Metal‐doped polyoxotitanium cages are a developing class of inorganic compounds which can be regarded as nano‐ and sub‐nano sized molecular relatives of metal‐doped titania nanoparticles. These species can serve as models for the ways in which dopant metal ions can be incorporated into metal‐doped titania (TiO2), a technologically important class of photocatalytic materials with broad applications in devices and pollution control. In this study a series of cobalt(II)‐containing cages in the size range ca. 0.7–1.3 nm have been synthesized and structurally characterized, allowing a coherent study of the factors affecting the band gaps in well‐defined metal‐doped model systems. Band structure calculations are consistent with experimental UV/Vis measurements of the TixOy absorption edges in these species and reveal that molecular dipole moment can have a profound effect on the band gap. The observation of a dipole‐induced band‐gap decrease mechanism provides a potentially general design strategy for the formation of low band‐gap inorganic cages.
Thread Insertion of a Bis(dipyridophenazine) Diruthenium Complex into the DNA Double Helix by the Extrusion of AT Base Pairs and Cross‐Linking of DNA Duplexes
Authors: Boer D. Roeland , Wu Lisha , Lincoln Per , Coll Miquel
Published: January 2014

The crystal structure of the Δ,Δ enantiomer of the binuclear “light‐switch” ruthenium complex [μ‐(11,11′‐bidppz)(1,10‐phenanthroline)4 Ru2]4+ bound to the oligonucleotide d(CGTACG) shows that one dppz moiety of the dumbbell‐like compound inserts into the DNA stack through the extrusion of an AT base pair. The second dppz moiety recruits a neighboring DNA molecule, and the complex thus cross‐links two adjacent duplexes by bridging their major grooves.
Highly Efficient Four‐Component Synthesis of 4(3H)‐Quinazolinones: Palladium‐Catalyzed Carbonylative Coupling Reactions
Authors: He Lin , Li Haoquan , Neumann Helfried , Beller Matthias , Wu Xiao‐Feng
Published: January 2014

Given the importance of quinazolinones and carbonylative transformations, a palladium‐catalyzed four‐component carbonylative coupling system for the synthesis of diverse 4(3H)‐quinazolinone in a concise and convergent fashion has been developed. Starting from 2‐bromoanilines (1 mmol), trimethyl orthoformate (2 mmol), and amines (1.1 mmol), under 10 bar of CO, the desired products were isolated in good yields in the presence of Pd(OAc)2 (2 mol %), BuPAd2 (6 mol %) in 1,4‐dioxane (2 mL) at 100 °C, using N,N‐diisopropylethylamine (2 mmol) as the base. Notably, the process tolerates the presence of various reactive functional groups and is very selective for quinazolinones, and was used in the synthesis of the precursor to the bioactive dihydrorutaempine.
Site‐Differentiated Polyboron Arenes Prepared by Direct CH Borylation and Their Highly Selective Suzuki–Miyaura Cross‐Coupling Reactions
Authors: Xu Liang , Ding Siyi , Li Pengfei
Published: January 2014

Di‐ and polyboron (hetero)arenes, site‐differentiated with MIDA boronyl (MIDA=N‐methyliminodiacetic acid) and pinacolato boronyl (Bpin), were prepared by an iridium‐catalyzed direct CH borylation of readily available (hetero)aryl MIDA boronates. The excellent synthetic uses of these multisite nucleophiles were demonstrated by the high‐yield production of a variety of multifunctionalized poly(hetero)arenes with the highly chemoselective Suzuki–Miyaura coupling (SMC) of the Bpin moiety being an essential step.
S‐((Phenylsulfonyl)difluoromethyl)thiophenium Salts: Carbon‐Selective Electrophilic Difluoromethylation of β‐Ketoesters, β‐Diketones, and Dicyanoalkylidenes
Authors: Wang Xin , Liu Guokai , Xu Xiu‐Hua , Shibata Naoyuki , Tokunaga Etsuko , Shibata Norio
Published: January 2014

S‐((Phenylsulfonyl)difluoromethyl)thiophenium salts were designed and prepared by a triflic acid catalyzed intramolecular cyclization of ortho‐ethynyl aryldifluoromethyl sulfanes. The thiophenium salts were found to be efficient as electrophilic difluoromehtylating reagents for introduction of a CF2H group to sp3‐hybridized carbon nucleophiles such as of β‐ketoesters and dicyanoalkylidenes. The (phenylsulfonyl)difluoromethyl group can be readily transformed into CF2H under mild reaction conditions. Enantioselective electrophilic difluoromethylation was also achieved in the presence of bis(cinchona) alkaloids.
An Electrochemically and Thermally Switchable Donor–Acceptor [c2]Daisy Chain Rotaxane
Authors: Bruns Carson J. , Li Jianing , Frasconi Marco , Schneebeli Severin T. , Iehl Julien , Jacquot de Rouville Henri‐Pierre , Stupp Samuel I. , Voth Gregory A. , Stoddart J. Fraser
Published: January 2014

Although motor proteins are essential cellular components that carry out biological processes by converting chemical energy into mechanical motion, their functions have been difficult to mimic in artificial synthetic systems. Daisy chains are a class of rotaxanes which have been targeted to serve as artificial molecular machines because their mechanically interlocked architectures enable them to contract and expand linearly, in a manner that is reminiscent of the sarcomeres of muscle tissue. The scope of external stimuli that can be used to control the musclelike motions of daisy chains remains limited, however, because of the narrow range of supramolecular motifs that have been utilized in their templated synthesis. Reported herein is a cyclic daisy chain dimer based on π‐associated donor–acceptor interactions, which can be actuated with either thermal or electrochemical stimuli. Molecular dynamics simulations have shown the daisy chain’s mechanism of extension/contraction in the ground state in atomistic detail.
Copper Nanoparticles on Graphene Support: An Efficient Photocatalyst for Coupling of Nitroaromatics in Visible Light
Authors: Guo Xiaoning , Hao Caihong , Jin Guoqiang , Zhu Huai‐Yong , Guo Xiang‐Yun
Published: January 2014

Copper is a low‐cost plasmonic metal. Efficient photocatalysts of copper nanoparticles on graphene support are successfully developed for controllably catalyzing the coupling reactions of aromatic nitro compounds to the corresponding azoxy or azo compounds under visible‐light irradiation. The coupling of nitrobenzene produces azoxybenzene with a yield of 90 % at 60 °C, but azobenzene with a yield of 96 % at 90 °C. When irradiated with natural sunlight (mean light intensity of 0.044 W cm−2) at about 35 °C, 70 % of the nitrobenzene is converted and 57 % of the product is azobenzene. The electrons of the copper nanoparticles gain the energy of the incident light through a localized surface plasmon resonance effect and photoexcitation of the bound electrons. The excited energetic electrons at the surface of the copper nanoparticles facilitate the cleavage of the NO bonds in the aromatic nitro compounds. Hence, the catalyzed coupling reaction can proceed under light irradiation and moderate conditions. This study provides a green photocatalytic route for the production of azo compounds and highlights a potential application for graphene.
Enhancement in the thermal and dynamic mechanical properties of high performance liquid crystalline epoxy composites through uniaxial orientation of mesogenic on carbon fiber
Authors: Guo Huilong , Lu Mangeng , Liang Liyan , Zheng Jian , Zhang Yunfei , Li Yinwen , Li Zhaoxia , Yang Chenghua
Published: January 2014

In this work, a high performance liquid crystalline epoxy composite was prepared and the effect of the alignment of LCE with long lateral substituent on the carbon fiber surface curing at low temperature on fracture toughness, dynamic mechanical, and thermal properties of liquid crystalline epoxy with lateral substituent (LCE6) was investigated by polarized optical microscopy (POM), wide angle X‐ray diffraction measurements (WAXS), dynamic mechanical analysis (DMA), thermogravimetric (TGA), and scanning electron microscopy (SEM). Curing degree of the composite was observed by FTIR. The experimental results indicate that the fracture toughness, glass transition temperature (Tg), thermal stability, degradation kinetics are associated with the alignment of LCE6 along long axis of carbon fiber. The alignment of LCE6 on carbon fiber surface can increase mesogen network density, which leads to higher fracture toughness, higher thermal stability, increase of the activation energies and higher Tg of the composite. The dynamic mechanical analysis shows that the compoaite possesses extremely higher dynamic storage moduli, which indicates that this LCE6/DDM/CF composite can be a high performance composite. Thus, the compoaite can be a potential candidate for advanced composites. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40363.
Fire‐retardant hybrid thermosetting resins from unsaturated polyesters and polysilazanes
Authors: Steffen Sebastian , Bauer Monika , Decker Daniel , Richter Frank
Published: January 2014

This introduces an organic–inorganic thermosetting hybrid resin system based on unsaturated polyester and polysilazanes. It shows the chemical modification of unsaturated polyester structures by end capping to enable the combination of both components. In general, halogen‐free unsaturated polyesters are not fire‐retardant and have to be equipped with additives. Fillers and intumescent additives are preponderantly used in today's fire‐retardant formulations. In contrast to these fire‐retardants, polysilazanes act as ceramizing agents. Polysilazanes are suitable fire‐retardants for resin transfer molding due to their low viscosity. Both burning behavior and glass transition temperature (Tg) are investigated as important application properties. In contrast to state‐of‐the‐art fire‐retardant formulations polysilazane‐based thermosetting hybrid resins burn with high intensity and fast extinction. Therefore, total heat and smoke emission is decreased. The formation of ceramic structures during burning results in high residual mechanical properties and a low mass loss. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40375.
Biobased thermosetting resins composed of L‐lysine methyl ester and bismaleimide
Authors: Ozawa Yuta , Shibata Mitsuhiro
Published: January 2014

Lysine methyl ester (LME), which was generated in situ by the reaction of lysine methyl ester dihydrochloride and triethylamine in dimethyl sulfoxide (DMSO), was prepolymerized with 4,4′‐bismaleimidodiphenylmethane (BMI) at 80°C for 2 h in DMSO. Then, the formed prepolymer was precipitated in water. The obtained LME/BMI prepolymers with molar ratios of 2:2, 2:3, and 2:4 were compression‐molded at a final temperature of 230°C for 2 h to produce cured lysine methyl ester/4,4′‐bismaleimidodiphenylmethane resins (cLBs; cLB22, cLB23, and cLB24, respectively). Fourier transform infrared (FTIR) analyses revealed that the Michael addition reaction of amino groups to the CC bonds of the maleimide group occurred in addition to the homopolymerization of the maleimide group. The glass‐transition temperature (Tg) and 5% weight loss temperature (T5) of the cured resin increased with increasing BMI feed content, and cLB24 showed the highest Tg (343°C) and T5 (389°C). The flexural strengths (131–150 MPa) and moduli (3.0–3.6 GPa) of the cLBs were comparable to those of the conventionally cured resins of BMI and 4,4′‐diaminodiphenylmethane. Field emission scanning electron microscopy analysis revealed that there was no phase separation for all of the cured resins. Although cLB23 and cLB24 were not biodegradable, cLB22 had a biodegradability of 8.5% after 30 days in an aerobic aqueous medium containing activated sludge. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40379.
Carbon‐Coated LiTi2(PO4)3: An Ideal Insertion Host for Lithium‐Ion and Sodium‐Ion Batteries
Authors: Aravindan Vanchiappan , Ling Wong Chui , Hartung Steffen , Bucher Nicolas , Madhavi Srinivasan
Published: January 2014

We report the extraordinary performance of carbon‐coated sodium super ion conductor (NASICON)‐type LiTi2(PO4)3 as an ideal host matrix for reversible insertion of both Li and Na ions. The NASICON‐type compound was prepared by means of a Pechini‐type polymerizable complex method and was subsequently carbon coated. Several characterization techniques such as XRD, thermogravimetric analysis (TGA), field‐emission (FE) SEM, TEM, and Raman analysis were used to study the physicochemical properties. Both guest species underwent a two‐phase insertion mechanism during the charge/discharge process that was clearly evidenced from galvanostatic and cyclic voltammetric studies. Unlike that of Li (≈1.5 moles of Li), Na insertion exhibits better reversibility (≈1.59 moles of Na) while experiencing a slightly higher capacity fade (≈8 % higher than Li) and polarization (780 mV) than Li. However, excellent rate capability profiles were noted for Na insertion relative to its counterpart Li. Overall, the Na insertion properties were found to be superior relative to Li insertion, which makes carbon‐coated NASICON‐type LiTi2(PO4)3 hosts attractive for the development of next‐generation batteries.