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X-ray diffraction/scattering computed tomography (XRS-CT) was used to create two-dimensional images, with 20 µm resolution, of passivated Co/TiO2/Mn Fischer-Tropsch catalyst extrudates postreaction after 300 h on stream under industrially relevant conditions. This combination of scattering techniques provided insights into both the spatial variation of the different cobalt phases and the influence that increasing Mn loading has on this. It also demonstrated the presence of a wax coating throughout the extrudate and its capacity to preserve the Co/Mn species in their state in the reactor. Correlating these findings with catalytic performance highlights the crucial phases and active sites within Fischer-Tropsch catalysts required for understanding the tunability of the product distribution between saturated hydrocarbons or oxygenate and olefin products. In particular, a Mn loading of 3 wt % led to an optimum equilibrium between the amount of hexagonal close-packed Co and Co2C phases resulting in maximum oxygenate selectivity. XRS-CT revealed Co2C to be located on the extrudates' periphery, while metallic Co phases were more prevalent toward the center, possibly due to a lower [CO] ratio there. Reduction at 450 °C of a 10 wt % Mn sample resulted in MnTiO3 formation, which inhibited carbide formation and alcohol selectivity. It is suggested that small MnO particles promote Co carburization by decreasing the CO dissociation barrier, and the Co2C phase promotes CO nondissociative adsorption leading to increased oxygenate selectivity. This study highlights the influence of Mn on the catalyst structure and function and the importance of studying catalysts under industrially relevant reaction times.

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Modifying traditional Co/TiO2-based Fischer-Tropsch (FT) catalysts with Mn promoters induces a selectivity shift from long-chain paraffins toward commercially desirable alcohols and olefins. In this work, we use in situ gas cell scanning transmission electron microscopy (STEM) with energy-dispersive X-ray spectroscopy (EDS) elemental mapping, and near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) to demonstrate how the elemental dispersion and chemical structure of the as-calcined materials evolve during the H2 activation heat treatment required for industrial CoMn/TiO2 FT catalysts. We find that Mn additions reduce both the mean Co particle diameter and the size distribution but that the Mn remains dispersed on the support after the activation step. Density functional theory calculations show that the slower surface diffusion of Mn is likely due to the lower number of energetically accessible sites for the Mn on the titania support and that favorable Co-Mn interactions likely cause greater dispersion and slower sintering of Co in the Mn-promoted catalyst. These mechanistic insights into how the introduction of Mn tunes the Co nanoparticle size can be applied to inform the design of future-supported nanoparticle catalysts for FT and other heterogeneous catalytic processes.

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INTRODUCTION: Plasma cell gingivitis (PCG) is a rare benign condition usually found on marginal and attached gingiva. This case details a generalized PCG, to include the management of the patient and clinicopathologic characteristics of the disorder. CASE PRESENTATION: The patient, a 24-year-old African American female, was referred to the periodontics clinic for severe generalized gingival erythema and edema. Past medical history review was remarkable for sickle cell anemia and systemic lupus erythematosus. The patient was initially prescribed dexamethasone oral rinse (0.5 mg/5 ml) pending biopsy and medical consult for potential causes of any hypersensitivity reaction. The patient also was instructed to discontinue her current type of oral mouthrinse and dentifrice. Biopsy results confirmed a diagnosis of PCG. Resolution of signs and symptoms started 1 month later, and approximately 2 years after initial diagnosis the patient was clinically stable. CONCLUSION: This report describes the management of a diffuse plasma cell gingivitis and reviews pertinent literature on the lesion. The etiology of PCG, although unclear, may be attributable to a hypersensitivity reaction. PCG may mimic other pathological entities, which underscores the importance of microscopic examination in establishing a definitive diagnosis before treatment initiation.

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BACKGROUND: Splenic flexure mobilization (SFM) during anterior resection is often debated given its increased operative complexity and lack of clear data suggesting oncological benefit. This study aimed to compare postoperative complications and 3-year oncological outcomes in patients undergoing anterior resection with and without SFM. METHODS: A retrospective single center observational study was performed. Notes review was performed for all patients undergoing anterior resection over a one-year period at a high-volume institution for sigmoid and rectal cancers. Anterior resections performed for benign disease or non-colorectal cancers were excluded. RESULTS: One hundred seventeen patients were included and 49 (41.9%) underwent SFM. 75 (64.1%) cases were completed laparoscopically and 48 (41%) resulted in stoma formation. SFM significantly increased the risk of minor Clavien Dindo Grade 1 postoperative complications (18.4% vs. 5.9%, P=0.03), however, it had no impact on more major postoperative complications, including anastomotic leaks (4.2% vs. 7.1%, P=0.52). There were no significant differences in median total lymph node yield (21.0% vs. 21.1, P=0.57) or R0 resection margin (93.9% vs. 94.1%, P=0.96). There was a non-significant trend towards lower overall recurrence rates in the SFM group (10.2% vs. 19.1%, P=0.19). CONCLUSIONS: In patients undergoing anterior resection for colorectal cancer, SFM provides no clear oncological benefit, but does increase the likelihood of minor postoperative complications. Whilst a trend towards lower overall recurrence rates was observed in the SFM group, this was not statistically significant. Therefore, SFM should be carefully considered on a case-by-case basis.

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INTRODUCTION: Prader-Willi syndrome (PWS) is a rare genetic multisystemic disease that is the most common inherited cause of severe childhood obesity. PWS patients are prone to significant oral and systemic health issues that detrimentally affect quality of life and decrease longevity. This report documents full-mouth pre-prosthetic surgical and restorative care in an adult PWS patient. CASE REPORT: The patient, a 29-year-old male, presented to the clinic accompanied by his guardians (parents) with the chief complaint that "My Teeth are breaking down and I would like to get them fixed". Periodontal and prosthetic comprehensive clinical and radiographic exams revealed a severely worn dentition, deep anterior overbite, altered passive eruption with generalized biofilm-induced gingivitis, and altered occlusal vertical dimension. Full mouth crown lengthening surgery combined with full mouth prosthodontic reconstruction was performed under parenteral sedation and local anesthesia. Completion of treatment was successful, and the patient was placed on a 3-month periodontal maintenance interval. DISCUSSION: Full mouth periodontal surgical and prosthodontic reconstruction on a PWS patient has not previously been reported in the literature. This case underscores the potential need for complex dental care in patients with this syndrome.

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An increasing number of outbreaks due to resistant non-albicans Candida species have been reported worldwide. Between 2014 and 2016, Candida isolates causing invasive candidiasis were recovered in a Mexican hospital. Isolates were identified to species level and antifungal susceptibility was determined. In the time period studied, 74 invasive candidiasis cases were identified, with 38% (28/74) caused by Candida parapsilosis, out of which 54% (15/28) were fluconazole resistant. The ERG11 gene was sequenced for 12 recoverable fluconazole-resistant C. parapsilosis isolates and SNPs identified. The 12 isolates had one common silent point mutation in ERG11 (T591C) and seven isolates had an additional (A395T) mutation, which corresponded to Y132F. Four of the isolates carrying this mutation were closely related within the same cluster by microsatellite typing. This is the first report of an invasive candidiasis outbreak in Mexico due to azole-resistant C. parapsilosis associated with the Y132F substitution.

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INTRODUCTION: Gingival fenestration (GF) is a distinct clinical entity of uncertain etiology that is seldom documented in the literature. It has been associated mainly with submucosal mechanical irritants such as calculus that subsequently create an opening in the oral soft tissue, usually at facial anterior sites. Surgical correction may be indicated to address functional and/or esthetic concerns. CASE PRESENTATION: The patient, a 74-year-old male, presented to the clinic with a chief complaint of "something is poking through my gum." Clinical exam revealed a gingival fenestration on the facial of tooth #11, associated with what appeared to be a pronounced noncarious cervical lesion (NCCL). Surgical treatment consisted of a connective tissue graft and odontoplasty of the sharp protruding edge of the root surface. Healing was uneventful with excellent closure of the fenestration and no evidence of recurrence after 18 months of follow-up. CONCLUSION: GF is a perforation of the mucosa typically associated with underlying sharp mechanical etiology. This report describes a fenestration that developed from a probable abfractive lesion, which later was successfully closed and exhibits long-term stability.

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OBJECTIVES: Vitamin D deficiency/insufficiency is a worldwide public health issue that has been linked to numerous inflammatory disorders, including periodontitis. There is increasing support for a role for adequate vitamin D levels in overall health. Populations with darker skin color have a higher prevalence of vitamin D deficiency/insufficiency and periodontitis. The purpose of this small pilot study was to investigate the influence of 12 weeks of 25(OH)D vitamin D supplementation (VDS) on mediators of systemic inflammation in dark-skinned, periodontitis patients. MATERIALS AND METHODS: A total of 23 patients with moderate to severe periodontitis were randomly assigned to the vitamin D group or placebo group and received intensive single visit scaling and root planning to elicit a systemic inflammatory response. RESULTS: Vitamin D supplementation increased serum 25(OH)D levels approximately 2-fold over baseline levels; moreover, VDS group had reduced peripheral blood CD3 and CD3+CD8+ cytotoxic T lymphocyte (CTLs) counts and reduced pro-inflammatory salivary cytokines. In contrast, VDS group had higher levels of the autophagy-related proteins and other proteins crucial for anti-microbial autophagy in whole blood PBMCs. CONCLUSION: In conclusion, VDS has multiple benefits for reducing systemic inflammation and promoting induction of autophagy-related proteins related to anti-microbial functions.

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Periodontal regeneration of lost tissue, including periodontal ligament (PDL), cementum, and bone, has evolved with regard to surgical techniques, biomaterials, and growth factors. Simultaneous orthodontic therapy and periodontal surgical treatment has been documented previously and shown to enhance the regenerative outcome due to stimulation of the PDL by tooth movement. This combined strategy is becoming increasingly common as clinicians explore the capabilities of a collaborative approach. This article presents a case series that documents three cases in which combined orthodontic and surgical procedures were used to enhance the regenerative outcome in challenging clinical scenarios. The article includes a review of the literature and discusses clinical factors related to increasing predictability in such cases.

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BACKGROUND: Increasing evidence implicates biofilms, consisting of species such as Porphyromonas gingivalis (Pg), in the etiology of peri-implantitis. Multiple approaches to ablate biofilms on failing implants have been proposed and include use of lasers, most recently the erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser. The purpose of this study is to establish an in vitro single-species biofilm model on implant surfaces and determine power settings of the Er,Cr:YSGG laser that remove biofilm without causing physical damage to disks. METHODS: Single-species biofilms consisting of Pg strain 381 were grown on titanium disks, including: 1) sandblasted, large-grit, acid-etched (SLA); 2) calcium phosphate nano-coated (CaP); 3) anodized; or 4) machined surfaces. Power settings from 0 to 1.5 W using an Er,Cr:YSGG laser equipped with radial firing tip were used. Biofilm formation/removal was quantitated using confocal and scanning electron microscopy. Surface changes in temperature, microroughness, and water contact angle were analyzed. RESULTS: Results show confluent Pg biofilm coating all disk surfaces. The laser removed biofilms from all surfaces, with CaP and SLA surfaces requiring power setting of 1.0 to 1.5 W for ablation of bacteria coating the disks. Within this power range, and with water spray, there were no changes in surface temperature, surface roughness, or contact angle on any surfaces tested. CONCLUSION: The Er,Cr:YSGG laser with radial firing tip and water spray was able to effectively ablate ≥95% of biofilm on all types of tested titanium surfaces, using clinically relevant power settings, without causing measurable physical changes to surfaces.

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INTRODUCTION: Gingival cysts of the adult (GCAs) are rare developmental soft tissue cysts usually found on the facial attached gingiva. Documented cases on the lingual aspect are extremely uncommon. This report details a lingual GCA along with distinguishing characteristics of this lesion. CASE PRESENTATION: The patient, a 37-year-old female, presented with a firm, round-shaped, bluish swelling on the lingual gingiva in the interproximal area between teeth #21 and #22. Radiographs revealed a circular radiolucency at the osseous crest. Surgical exploration showed cystic-appearing tissue with accompanying bone resorption. Histologic examination, along with clinical presentation, confirmed a diagnosis of gingival cyst. Healing was uneventful with no evidence of recurrence at a 5-month recall. CONCLUSIONS: A GCA is usually of odontogenic origin and occurs typically in the attached gingiva of the mandibular premolar region. Occasionally, it demonstrates radiographic evidence of bone loss from pressure resorption. Its more frequent intraosseous counterpart, the lateral periodontal cyst, shares histopathologic characteristics with the GCA. These findings underscore the importance in establishing a definitive diagnosis.

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OBJECTIVE: The goal of this study was to reveal clinical and pathologic findings on idiopathic bone cavity lesions (IBC). STUDY DESIGN: A retrospective analysis of 20 IBC cases diagnosed from 2004 to 2014 from a university-based maxillofacial pathology service was performed and included all pertinent clinical, histologic, and radiographic findings. RESULTS: Eleven women (age = 36 ± 12.7) and 9 men (age = 23 ± 17.9) diagnosed with IBC were selected for analysis. There was a higher African-American female predilection (40%). Thirty percent of the cases were associated with florid cementoosseous dysplasia (COD) (all middle-aged African-American women). The location of the lesions was mandibular in 85% of the patients. All symptomatic patients (25%) had concomitant COD. Only 1 patient reported previous trauma, and only 1 patient had prior orthodontic treatment. Follow-up period ranged from 1 to 8 years, with only 1 recurrence 3 years after surgery. CONCLUSIONS: The results suggest that IBC concurrent with COD may not be as rare as the literature implies. Clinicians must be attentive to this possible relationship to ensure accurate diagnosis and appropriate treatment.

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Hiccups, or singulata (hiccup is singultus), are commonly experienced by most people at one time or another and are usually brief and self-limiting. Although pharmacotherapeutic agents are not generally considered causal in the etiology of hiccups, many clinicians empirically associate episodic hiccups in their patients as being drug induced. The two classes of drugs most often cited as causing hiccups are corticosteroids and benzodiazepines. This report involved a patient who was given preoperative dexamethasone and developed hiccups before anesthesia and surgery commenced. He at no time was in distress, and the surgical procedure was completed without complication. By the second postsurgical day his hiccups were resolved completely. Although the association may be anecdotal, many clinicians consider hiccups a potential side effect of steroid therapy, especially high doses of steroids. Of interest in this case is the relatively low dose of corticosteroid used, albeit apparently linked to his hiccups. Practitioners should be aware of this potential condition.

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Tailgut cysts are rare congenital anomalies, believed to be remnants of the primitive embryonic hindgut. In addition to causing genitourinary and bowel obstructive symptoms, they have been reported to harbour occult adenocarcinoma. Varying positions of a tailgut cyst with respect to the rectum have also been reported in literature. We present a rare presentation of this disease vis a vis obstipation and acute urinary retention in a 70 year old man.

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Retrorectal hamartomas or tail gut cysts are rare congenital anomalies most commonly seen in a retrorectal location; most common in middle aged women. This article describes the radiological appearance in two cases of tail gut cysts in males, one a child with a visible perianal swelling since birth and the other, a 72-year-old man with symptoms for one week. In both, the tailgut cysts were in a right perirectal location. Presentation in such a location in males, at extremes of age, is unusual for tailgut cysts.

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Demineralized freeze-dried bone (DFDB) in matrix form must be rehydrated with a carrier medium which allows for easy manipulation during periodontal surgery. The purpose of this study was to evaluate how human DFDB suspended in a polyol matrix affects new bone formation in the rat calvarium critical-sized defect (CSD) model. Fifty-five adult male Harlan Sprague-Dawley rats were assigned to 1 of 5 treatment groups: polyol, 100% DFDB, 47% DFDB/polyol, 47% DFDB, or an unfilled control. They were then placed into 8-m calvarial CSDs. The bone donor source company for the DFDB and DFDB/polyol groups was the same. Calvaria were harvested 10 weeks after surgery and evaluated histomorphometrically. The diameter of bone particles from the 3 groups containing DFDB was measured by scanning electron microscopy. There was no statistically significant difference in the percentage of bone fill between any of the groups, although the 100% DFDB group exhibited the most bone fill. The 47% DFDB/polyol and 47% DFDB groups had similar amounts of bone formation. The average size of the demineralized bone particles from the 100% DFDB group was significantly smaller than that of the other 2 groups containing DFDB. Adding a polyol to DFDB produced similar osseous regeneration in the rat calvarium defect model vs DFDB alone. Yet from a clinical standpoint, the polyol enhanced graft handling and stability. Graft particle size may have an effect on bone fill.

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BACKGROUND: Cigarette smoking can adversely affect the results of many periodontal procedures. The purpose of this study was to determine whether cigarette smoking affects wound healing of subepithelial connective tissue grafts. METHODS: Seventeen systemically healthy patients with 22 Miller Class I or II mucogingival defects were divided into a non-smoker group or smoker group. Patients were regarded as smokers if they reported smoking 10 to 20 cigarettes per day. The following parameters were documented at the surgery date and 3 and 6 months postoperatively: recession depth (RD), recession width (RW), keratinized gingiva height measured apico-coronally (KG), relative attachment level (RAL), probing depths (PD), bleeding on probing (BOP), and the full-mouth plaque score (FMP). Salivary cotinine samples were taken at the surgery to confirm the smoking history and to quantify cigarette use. RESULTS: Non-smokers (0- to 10-ng/ml cotinine level) healed with statistically more recession coverage than the smokers (>10-ng/ml cotinine level) (98.3% versus 82.3%, respectively; P=0.001). Six months postoperatively, the non-smokers healed with a 0.2-mm mean recession depth compared to a 1.0-mm mean recession depth for the smokers. This difference in recession depth was statistically significant (P=0.014). CONCLUSIONS: Root coverage with connective tissue grafts appears to be negatively associated with cigarette smoking. Smokers should consider smoking cessation or reducing the use of cigarettes for optimal results with connective tissue grafts.

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Demineralized freeze-dried bone allograft (DFDBA), a widely used graft material in periodontal regenerative procedures, is processed with hydrochloric acid in the attempt to expose proteins located within the bone matrixes that are capable of inducing new bone formation. However, the degree of DFDBA demineralization varies between tissue banks, which may have an effect on clinical regeneration. This study uses the critical-sized defect (CSD) model to evaluate the wound-healing response to the residual calcium of donor bone. If the percentage of residual calcium in a graft were demonstrated to significantly enhance wound healing, then periodontal patients may benefit from further standardization of human-allograft processing. Sixty adult, male, Harlan Sprague-Dawley rats (Rattus norvegicus) were randomly and equally divided into 4 test groups (ie, DFDBA at 1%, 2%, and 3% to 6% residual calcium levels and FDBA at 23% residual calcium) and a control group (no allograft). An 8-mm-diameter craniotomy was made in the rat calvarium, and polytetrafluoroethylene membranes with pore sizes of 0.50 microm were placed intracranially and ectocranially. Treatment materials were carefully placed into the CSD with a new sterilized dental amalgam carrier. Tetracycline hydrochloride was injected intraperitoneally for labeling new bone growth, and animals were euthanized 12 weeks postsurgery. As a result, histomorphometric bone fill at 12 weeks showed a statistically significant increase in the 2% DFDBA group as compared to all other groups. The authors conclude that a 2% residual calcium level in human DFDBA appears to significantly (P < or = .05) enhance osseous wound healing in the rat calvarium.

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BACKGROUND: Bony defects caused by periodontitis are often treated by regenerative therapy using autografts and/or allografts. Alloplasts, such as hydroxyapatite or ceramics, are also used as osteoconductive materials that serve as a scaffold for new bony ingrowth. The purpose of this study was to determine the effect of hydroxyapatite tricalcium phosphate (HA-TCP) on osseous repair in the rat calvarium. METHODS: Forty-four adult male Harlan Sprague-Dawley rats were assigned to one of four treatment groups: HA-TCP macroporous disk, HA-TCP microporous disk, HA-TCP granules, and demineralized freeze-dried bone (DFDB). The materials were placed into 8-mm calvarial critical-size defects (CSD). Calvariae were harvested at 10 weeks post-surgery and evaluated histomorphometrically. RESULTS: The DFDB group had significantly (P <0.05) more new bone formation (47%) than any other group. The HA-TCP macroporous disk group had significantly (P <0.05) more new bone formation (19.7%) than the HA-TCP microporous disk (8.5%) or HA-TCP granule (6.9%) groups. CONCLUSIONS: The HA-TCP macroporous disk may elicit significant new bone formation due to its rigid space-maintaining scaffold and pore size for vascular ingrowth. It is well tolerated by host tissues and may be a suitable carrier for growth factors.

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Cemental separations and tears are secondary etiological factors that may lead to rapid periodontal destruction if the lesion communicates with the oral cavity and allows bacterial invasion. Although many cemental tears that occur on proximal surfaces can be diagnosed radiographically, separations on the facial or lingual surface that cannot be detected on radiographs may present a diagnostic dilemma. This article describes a case of lingual cemental separation on a maxillary incisor, with subsequent successful surgical correction utilizing an osseous graft.

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