Young adults' intention to quit using JUUL.

BACKGROUND: With research indicating some young audiences may desire to quit using JUUL, a high-nicotine e-cigarette, we sought to explore factors that may motivate them to quit. METHODS: This sequential, mixed methods study included a cross-sectional online survey of college students (n = 631) followed by in-person interviews (n = 51) with survey participants. Data were collected March-April 2019. The survey asked about intention to quit using JUUL. A latent class analysis (LCA) identified participant groups who would quit for various reasons. Participants were also asked 'Can you be too old to JUUL?' during the survey. During the interviews, participants were provided preliminary survey findings and asked about their perceptions of the data. Interview participants were also asked about their expectations for future use of JUUL. RESULTS: Four classes emerged from the LCA, indicating costs to self (i.e., harm to lungs/brain, price; 46.8%), financial costs (36.6%), all costs (e.g., social, monetary, health; 9.3%), and harm to self (7.3%) may have influenced our sample's decision to quit using JUUL. Interviewees affirmed desires to quit using JUUL, especially after leaving college. Only 27.19% of survey participants reported an age threshold for using JUUL (M = 31.8 years, SD = 10.0); however, several interviewees explained that although someone could not be too old to JUUL, it would be 'immature' or 'childish' for adults who were not trying to quit smoking to use JUUL socially. DISCUSSION: Comprehensive tobacco control strategies such as taxing e-cigarettes, marketing campaigns, and nicotine cessation programs are needed to help nicotine dependent young adults quit using high-nicotine e-cigarettes.

Nitrogen sources affect productivity, desiccation tolerance and storage stability of Beauveria bassiana blastospores.

AIMS: Nitrogen is a critical element in industrial fermentation media. This study investigated the influence of various nitrogen sources on blastospore production, desiccation tolerance and storage stability using two strains of the cosmopolitan insect-pathogenic fungus Beauveria bassiana. METHODS AND RESULTS: Complex organic sources of nitrogen such as soy flour, autolysed yeast and cottonseed flour induced great numbers of blastospores after 2-3 days of fermentation, which also survived drying and remained viable (32-56% survival) after 9 months storage at 4°C, although variations were found between strains. Nitrogen availability in the form of free amino acids directly influenced blastospore production and resistance to desiccation. Increasing glucose and nitrogen concentrations up to 120 and 30 g l-1 , respectively, did not improve blastospore production but enhanced desiccation tolerance. Cell viability after drying and upon fast-rehydration was increased when ≥25 g acid-hydrolysed casein per litre was supplemented in the liquid culture medium. CONCLUSIONS: These findings indicate that low-cost complex nitrogen compounds are suitable to enhance yeast-like growth by B. bassiana with good desiccation tolerance and therefore support its further scale-up production as a mycoinsecticide. SIGNIFICANCE AND IMPACT OF THE STUDY: Nitrogen is the most expensive nutrient in liquid media composition, but this study underscores the feasibility of using low-cost nitrogen compounds composed mainly of agro-industrial by-products for rapid production of desiccation-tolerant B. bassiana blastospores by liquid culture fermentation.

First record of epizootics in the ocola skipper, Panoquina ocola (Lepidopera: Hesperiidae), caused by Isaria tenuipes in flooded rice fields of Central Brazil.

AIMS: We report the first occurrence of an epizootic of the ascomycete fungus, Isaria tenuipes (teleomorph Cordyceps takaomontana), on the ocola skipper Panoquina ocola (Lepidoptera: Hesperiidae), an insect pest affecting rice in Brazil. METHODS AND RESULTS: Field surveys in flooded rice fields in the state of Goiás in Brazil were conducted, and a fungal pathogen of a caterpillar pest (P. ocola) was serendipitously found. This fungus inflicted high infection levels (average 86·2%) mainly to the pupal stage during warm, humid growing conditions. Typically, mycosed pupal cadavers produced milky-white to pale yellow synnemata bearing an average of 1·1 ± 0·2 × 109 conidia per cadaver. Based on phylogenetic analysis using beta-tubulin gene sequences, we confirmed that all 12 isolates obtained from field-mummified pupae were identifiable as I. tenuipes. CONCLUSIONS: Our data expand our knowledge on the host and geographical ranges of this mycopathogen and underscore its epizootic potential to affect a lepidopterous insect pest on rice in Brazil. This finding may facilitate the exploitation of this fungus as a mycoinsecticide. SIGNIFICANCE AND IMPACT OF THE STUDY: Isaria tenuipes may be used as an effective and environmentally friendly bioinsecticide against agricultural caterpillar pests due to its epizootic potential, as well as explored for medicinal purposes by pharmaceutical industry.

Nepetalactones from essential oil of Nepeta cataria represent a stable fly feeding and oviposition repellent.

The stable fly, Stomoxys calcitrans (L.) (Diptera: Muscidae), is one of the most serious pests to livestock. It feeds mainly on cattle and causes significant economic losses in the cattle industry. Standard stable fly control involving insecticides and sanitation is usually costly and often has limited effectiveness. As we continue to evaluate and develop safer fly control strategies, the present study reports on the effectiveness of catnip (Nepeta cataria L.) oil and its constituent compounds, nepetalactones, as stable fly repellents. The essential oil of catnip reduced the feeding of stable flies by >96% in an in vitro bioassay system, compared with other sesquiterpene-rich plant oils (e.g. amyris and sandalwood). Catnip oil demonstrated strong repellency against stable flies relative to other chemicals for repelling biting insects, including isolongifolenone, 2-methylpiperidinyl-3-cyclohexen-1-carboxamide and (1S,2'S)-2-methylpiperidinyl-3-cyclohexen-1-carboxamide. The repellency against stable flies of the most commonly used mosquito repellent, DEET, was relatively low. In field trials, two formulations of catnip oil provided >95% protection and were effective for up to 6 h when tested on cattle. Catnip oil also acted as a strong oviposition repellent and reduced gravid stable fly oviposition by 98%.

Developing wax-based granule formulations for mating disruption of oriental beetles (Coleoptera: Scarabaeidae) in turfgrass.

Oriental beetle, Anomala orientalis Waterhouse (Coleoptera: Scarabaeidae), is a pest of turfgrass that may be controlled by applications of synthetic pheromone (Z)-/ (E)-7-tetradecen-2-one to disrupt mating. Laboratory experiments were conducted to determine release profiles of pheromone from experimental wax-based granules, a proprietary wax granule, and rubber septa commonly used in pheromone traps. Rubber septa loaded with 10, 100, and 300 microg per septum provided steady rates of pheromone release (zero-order) over 4 wk of laboratory evaluation (total = 1.1, 9.0, and 26.9 microg/4 wk, respectively). Septa with 1,000 microg per septum had a significant decline in the rate of pheromone release for this 4-wk exposure time (total = 119 microg/4 wk). A large proprietary wax granule (44 mg per granule, 25% wt:wt pheromone) provided a steady rate of pheromone release (total = 2,347 microg/4 wk per granule). Experimental granules (16 mg per granule) made of soywax with higher pheromone loads (10% wt:wt) approached zero-order release (steady state) (total = 69 microg/4 wk per granule), whereas smaller granules (4 mg per granule) with less pheromone (0.1% wt:wt) provided first-order release profiles (decreasing rate with longer exposure time) (total = 0.35 microg/4 wk per granule). A field trial in turfgrass demonstrated the potential of selected granular formulations to provide effective mating disruption for up to 4 wk, as measured by pheromone trap shutdown. Documenting pheromone release profiles for these experimental granules and rubber septa provides valuable information that will support future field evaluations of mating disruption as a control strategy.

Part II. Chromatography using ultra-stable metal oxide-based stationary phases for HPLC.

In this part of the review authors discuss methods used for modification of metal oxide surfaces. On the basis of literature data it is shown, that silanization of the surfaces do not form stable supports for chromatography. On the other hand, the success of polymer modified surfaces such as polybutadiene (PBD) and polystyrene (PS) is emphasized. Permanent modification of metal oxide surfaces with Lewis bases is also widely discussed. Chromatographic properties of polymer modified surfaces of zirconia are discussed in details. The perspectives of carbon-coated metal oxide surfaces in HPLC and high temperature separations are described.

Part I. Chromatography using ultra-stable metal oxide-based stationary phases for HPLC.

The first part of the review contrasts the main drawbacks of silica-based packings such as their relative thermal and chemical instability with excellent stability of metal oxides. The paper concerns mainly ZrO2, TiO2 and Al2O3. Methods of preparation of spherical particles for HPLC are described. Surface chemistry of the oxides is, however, very different from that of silica. Ability of the oxides to ion- and ligand exchange is discussed from a chromatographic point of view.

Insight into the catalytic mechanism of DNA polymerase beta: structures of intermediate complexes.

The catalytic reaction mediated by DNA polymerases is known to require two Mg(II) ions, one associated with dNTP binding and the other involved in metal ion catalysis of the chemical step. Here we report a functional intermediate structure of a DNA polymerase with only one metal ion bound, the DNA polymerase beta-DNA template-primer-chromium(III).2'-deoxythymidine 5'-beta,gamma-methylenetriphosphate [Cr(III).dTMPPCP] complex, at 2.6 A resolution. The complex is distinct from the structures of other polymerase-DNA-ddNTP complexes in that the 3'-terminus of the primer has a free hydroxyl group. Hence, this structure represents a fully functional intermediate state. Support for this contention is provided by the observation of turnover in biochemical assays of crystallized protein as well as from the determination that soaking Pol beta crystals with Mn(II) ions leads to formation of the product complex, Pol beta-DNA-Cr(III).PCP, whose structure is also reported. An important feature of both structures is that the fingers subdomain is closed, similar to structures of other ternary complexes in which both metal ion sites are occupied. These results suggest that closing of the fingers subdomain is induced specifically by binding of the metal-dNTP complex prior to binding of the catalytic Mg(2+) ion. This has led us to reevaluate our previous evidence regarding the existence of a rate-limiting conformational change in Pol beta's reaction pathway. The results of stopped-flow studies suggest that there is no detectable rate-limiting conformational change step.

New isotopic evidence for chronic lead contamination in the San Francisco Bay estuary system: implications for the persistence of past industrial lead emissions in the biosphere.

Measurements of lead isotope compositions in unfiltered San Francisco Bay waters from 1989 to 1998 have brought new insights into the cycling of anthropogenic lead in estuaries. Isotopic compositions of lead in the shallow (<2 m) southern reach were essentially invariant ( approximately 90% derived from 1960s-1970s leaded gasoline) during the study period because of limited hydraulic flushing and the remobilization of lead from bottom sediments. In contrast, in the northern reach freshwater flushing from the San Joaquin and Sacramento rivers produced seasonal and decadal variations in lead isotope compositions. The seasonal shifts are attributed to advection of soils containing late 1980s gasoline lead into the bay during winter rains. Mass balance calculations indicate that only a small fraction (1-10%) of this leaded gasoline fallout from the late 1980s has been washed out of the San Joaquin and Sacramento rivers' drainage basin by 1995. Superimposed on this seasonal cycling was a long-term systematic shift in the component of gasoline lead expressed in the river systems, with a small ( approximately 5-10%) decrease in the amount of 1960s-1970s gasoline lead in river and North Bay waters. The retention of gasoline lead in the river systems draining into the bay as well as San Francisco Bay sediments indicates that historic gasoline deposits may remain in the combined riparian/estuarine system for decades. Such a persistence is in contraindication to recent reports of rapid (annual) decreases in lead contamination in other environments, and the link between climate and contaminant transport suggests local or global climate change will have an impact on contaminant distribution and fate.

Odontogenic fibroma.

The odontogenic fibroma is a rare tumor that has generated controversy, perhaps disproportionately to its importance in the family of odontogenic tumors. The clinical and radiographic features are well documented but the histologic aspects have generated controversy. The behavior is benign, and published accounts indicate a low recurrence rate following treatment by curettage. The tumor recognized by the World Health Organization (WHO) is the legitimate odontogenic fibroma. Histologic variants include the granular cell type and the hybrid odontogenic fibroma giant cell-like tumor. Although the extraosseous "peripheral" odontogenic fibroma presents as a gingival enlargement clinically indistinguishable from other gingival lesions, its histomorphology is similar to the central tumor. A normal dental follicle around the crown of an unerupted tooth may histologically mimic the odontogenic fibroma and other odontogenic tumors.

Epidermolysis bullosa: case report of appropriate classification of subtype because of an early dental exam.

Epidermolysis bullosa is a unique group of disorders that have blister formation as the common feature. Although there are many variants of this disorder, the subtypes are classified into three groups based upon the level of tissue separation that occurs after mechanical trauma is sustained by the skin. Specific subtypes of EB may have substantial involvement of extracutaneous areas such as the oral cavity and dentition. This case report demonstrates the importance of a dental examination at an early age in order to facilitate the correct subtyping of EB. For the very young patient, correct classification of the subtype of EB may be very important in identifying the severity of clinical features associated with the disorder, and with this information the patient and family may become better aware of potential complications of the disorder such as the dental defects described in this report.

An in vivo evaluation of an electronic apex locator that uses the ratio method in vital and necrotic canals.

The purpose of this study was to compare the canal length determined by an apex locator to the apical constriction in both vital and necrotic canals. Informed consent was obtained from patients waiting to have teeth extracted. The teeth were anesthetized, isolated, and accessed. The pulp was considered vital if bleeding was present in the pulp chamber. The Root ZX was used to measure the root canal length. The file was cemented into place, and the tooth was extracted. Twenty-nine teeth containing 34 cemented files were studied, and the distance from the apical constriction was measured. The Root ZX was 82.3% accurate to within 0.5 mm of the apical constriction. The mean distance from the apical constriction was 0.21 mm in vital cases versus 0.49 mm for necrotic cases. There was no statistical difference between the ability of the Root ZX to determine the apical constriction in vital canals versus necrotic canals.

Lichen sclerosus et atrophicus of the oral cavity: report of two cases.

Lichen sclerosus et atrophicus is a depigmenting mucocutaneous disease most frequently affecting the female genitalia. Genital lesions are symptomatic and may be functionally debilitating. Oral lesions are of little significance other than the esthetic concerns of perioral lesions. In view of the rarity of reported cases, one lesion of the labial mucocutaneous area and a second of the palate are presented along with a description of the disease's clinical and histopathologic findings and a brief review of the literature. The lip lesion was partially resolved with topical corticosteroids and was then fully eliminated with topical testosterone. Histologic verification and examination for the simultaneous occurrence or absence of oral and the more common genital-cutaneous lesions is essential if meaningful information in the medical-dental literature is to be obtained in the future.

Atypical palatal papillomatosis treated by excision and full-thickness grafting.

Papillary lesions of the oral cavity are extremely common, and inflammatory palatal hyperplasia is well known to dental practitioners. Advanced sophistication in viral laboratory technologies makes it apparent that various forms of the human papilloma virus are often causative. However, this is not true for inflammatory palatal hyperplasia. This article describes a patient with anatomically well-demarcated, multiple squamous cell papillomas of the palate that could not be classified as inflammatory palatal hyperplasia, nor could a viral etiology be ascertained, despite exhaustive laboratory studies. The lesion recurred despite numerous surgical ablation attempts. Eradication was achieved only after applying free soft-tissue grafts over the areas of excision. The differential diagnosis of papillary lesions with an emphasis on viral etiology, laboratory studies associated with their identification, and a hypothesis that explains why grafting was the only successful means of treatment are also discussed.

Chronic stomatitis: an early sign of Crohn's disease.

The authors describe an 11-year-old boy who had persistent oral lesions that clinically mimicked first-episode herpetic stomatitis. A biopsy revealed noncaseating sterile granulomas. Investigation of the small and large bowels revealed that the child had Crohn's disease. The oral lesions responded favorably to topical steroid therapy. The authors also discuss the range of oral lesions in inflammatory bowel disease and the differential diagnoses.

Synthesis and chromatographic characterization of dextran-coated zirconia high-performance liquid chromatographic stationary phases.

Porous zirconia particles made by the oil emulsion (OE) method and the polymerization-induced colloid aggregation (PICA) method have been coated with a small, carboxymethylated (approximately 5%) dextran polymer and crosslinked in place. The parameters of the coating process (dextran concentration, adsorption time and crosslinker concentration) have all been examined and an optimum value for each determined. The coated and uncoated materials were characterized by nitrogen sorptometry and size-exclusion chromatography (SEC) using solutes (polystyrenes and dextrans) of well-defined molecular masses. Nitrogen sorptometry results show that the PICA material has a much lower pore volume and smaller pore diameter than do the OE materials. Despite this, the elution volumes of the SEC probes change very little upon polymer coating the PICA material while the OE material shows a very large change upon coating.

Post-rhizotomy periodontal atrophy.

This report details the experience of two people who suffered a unique type of periodontal atrophy following trigeminal sensory rhizotomy. The cause is unknown but it may be the result of unintentional self-mutilation.

Radiologic findings of diseases involving the maxilla and mandible.

The purpose of this pictorial essay is to illustrate the radiologic appearances of diseases involving the maxilla and mandible. The high prevalence of dental disease results in inflammatory, infectious, and reactive processes that must be distinguished from more serious conditions with similar radiologic features. Because of their association with odontogenic tissues, lesions of the maxilla and mandible may have radiologic findings not seen in other bones. Furthermore, nonodontogenic cysts and tumors that occur elsewhere in the skeleton may exhibit unique radiologic characteristics when associated with teeth. This pictorial essay presents the radiologic characteristics of inflammatory lesions, developmental abnormalities, fibroosseous lesions, benign cysts and tumors, and malignant lesions of the maxilla and mandible.