RESUMO
BACKGROUND: An increased incidence of Pseudomonas aeruginosa in microbiological surveillance (MS) cultures from gastrointestinal endoscopes was detected between March 2020 and March 2023 in Tan Tock Seng Hospital Singapore. AIM: To describe the use of whole-genome sequencing (WGS) in this investigation. METHODS: WGS was performed for all P. aeruginosa isolates with pairwise comparison of isolates to assess for genomic linkage. Comprehensive review of reprocessing practices and environmental sampling was performed. FINDINGS: Twenty-two P. aeruginosa isolates were detected from endoscopic MS cultures. Fifteen (68%) isolates were available for WGS. Eighteen pairwise comparisons of isolates were made, of which 10 were found to be genomically linked. One endoscope had P. aeruginosa repeatedly cultured from subsequent MS that were genomically linked and persistent despite repeat endoscopic reprocessing, establishing the persistence of biofilm that could not be eradicated with routine reprocessing. All P. aeruginosa isolates cultured from other different endoscopes were genetically distinct. Investigation into reprocessing practices revealed the use of air/water valves connected to endoscopes during clinical use. Inspection of these valves revealed the presences of cracks and tears. All other environmental samples were negative. CONCLUSION: The WGS findings helped to deprioritize common source contamination and supported the hypothesis of biofilm build-up within endoscopes, leading to repeatedly positive MS cultures that were genomically linked. This was possibly related to incomplete reprocessing of the damaged air/water valves, resulting in biofilm build-up. All faulty valves were changed and subsequently cleaned separately with ultrasonic cleaning followed by sterilization which resolved this incident.
RESUMO
PURPOSE: A feasibility study to evaluate the Chabner XRT® Radiation Bra (CIVCO Radiotherapy & Qfix, Coralville, IA, USA) as a customised immobilisation device for patients with pendulous breasts undergoing radiotherapy was conducted. METHODS: A total of 34 patients with large pendulous breasts were fitted with the Chabner XRT® Radiation Bra during RT. A mixed-method questionnaire was administered to both radiation therapists (RTTs) and patients. RTTs evaluated the effectiveness of the bra in setup. Patients appraised its comfort level and ease of wearing. Setup reproducibility was evaluated based on a departmental imaging protocol. Acute skin side effects were documented with photos and assessed using the Radiation Therapy Oncology Group (RTOG) classification. RESULTS: Of the patients, 27 (79.4%) completed the questionnaire. 23 patients felt comfortable wearing the bra while 20 felt less exposed during treatment. Reproducibility was acceptable, with a median (range) setup error (isocentre) of 0.0â¯cm (-0.6 to 0.7â¯cm; left/right), -0.1â¯cm (-0.5 to 1.2â¯cm; posterior) and 0.2â¯cm (-0.5 to 0.9â¯cm; inferior) achieved based on matched field borders on skin. However, repeated setups and imaging were required for 3 patients due to large breast size (cups D-G; size 4-5). Minimal skin toxicity (grade 0-1) was observed. No grade ≥â¯2 was reported. 10 RTTs completed the survey. Male RTTs (nâ¯= 4) were not confident in assisting patients with bra fitting. 8 RTTs agreed that although it was difficult to reproduce the breast tissue for treatment, it helped patients to maintain the treatment position. CONCLUSION: Our study demonstrated the feasibility of using a customised bra which provided optimal setup reproducibility while maintaining minimal skin toxicity and patient comfort, especially the value-added modesty felt among Asian women during their breast cancer radiotherapy.
Assuntos
Neoplasias da Mama , Radioterapia (Especialidade) , Humanos , Feminino , Masculino , Reprodutibilidade dos Testes , Mama , Neoplasias da Mama/radioterapiaRESUMO
The aim of this article is to show a way to extend the usefulness of the Generalized Bernoulli Method (GBM) with the purpose to apply it for the case of variational problems with functionals that depend explicitly of all the variables. Moreover, after expressing the Euler equations in terms of this extension of GBM, we will see that the resulting equations acquire a symmetric form, which is not shared by the known Euler equations. We will see that this symmetry is useful because it allows us to recall these equations with ease. The presentation of three examples shows that by applying GBM, the Euler equations are obtained just as well as it does the known Euler formalism but with much less effort, which makes GBM ideal for practical applications. In fact, given a variational problem, GBM establishes the corresponding Euler equations by means of a systematic procedure, which is easy to recall, based in both elementary calculus and algebra without having to memorize the known formulas. Finally, in order to extend the practical applications of the proposed method, this work will employ GBM with the purpose to apply it for the case of solving isoperimetric problems.
RESUMO
Nonlinear piezoelectric materials are raised as a great replacement for devices that require low power consumption, high sensitivity, and accurate transduction, fitting with the demanding requirements of new technologies such as the Fifth-Generation of telecommunications (5G), the Internet of Things (IoT), and modern radio frequency (RF) applications. In this work, the state equations that correctly predict the nonlinear piezoelectric phenomena observed experimentally are presented. Furthermore, we developed a fast methodology to implement the state equations in the main FEM simulation software, allowing an easy design and characterization of this type of device, as the symmetry structures for high-order tensors are shown and explained. The operation regime of each high-order tensor is discussed and connected with the main nonlinear phenomena reported in the literature. Finally, to demonstrate our theoretical deductions, we used the experimental measurements, which presented the nonlinear effects, which were reproduced through simulations, obtaining maximum percent errors for the effective elasticity constants, relative effective permittivity, and resonance frequencies of 0.79%, 2.9%, and 0.3%, respectively, giving a proof of the potential of the nonlinear state equations presented for the unifying of all nonlinear phenomena observed in the piezoelectric devices.
RESUMO
Structures made by scleractinian corals support diverse ocean ecosystems. Despite the importance of coral skeletons and their predicted vulnerability to climate change, few studies have examined the mechanical and crystallographic properties of coral skeletons at the micro- and nano-scales. Here, we investigated the interplay of crystallographic and microarchitectural organization with mechanical anisotropy within Porites skeletons by measuring Young's modulus and hardness along surfaces transverse and longitudinal to the primary coral growth direction. We observed micro-scale anisotropy, where the transverse surface had greater Young's modulus and hardness by â¼ 6 GPa and 0.2 GPa, respectively. Electron backscatter diffraction (EBSD) revealed that this surface also had a higher percentage of crystals oriented with the a-axis between ± 30-60∘, relative to the longitudinal surface, and a broader grain size distribution. Within a region containing a sharp microscale gradient in Young's modulus, nanoscale indentation mapping, energy dispersive spectroscopy (EDS), EBSD, and Raman crystallography were performed. A correlative trend showed higher Young's modulus and hardness in regions with individual crystal bases (c-axis) facing upward, and in crystal fibers relative to centers of calcification. These relationships highlight the difference in mechanical properties between scales (i.e. crystals, crystal bundles, grains). Observations of crystal orientation and mechanical properties suggest that anisotropy is driven by microscale organization and crystal packing rather than intrinsic crystal anisotropy. In comparison with previous observations of nanoscale isotropy in corals, our results illustrate the role of hierarchical architecture in coral skeletons and the influence of biotic and abiotic factors on mechanical properties at different scales. STATEMENT OF SIGNIFICANCE: Coral biomineralization and the ability of corals' skeletal structure to withstand biotic and abiotic forces underpins the success of reef ecosystems. At the microscale, we show increased skeletal stiffness and hardness perpendicular to the coral growth direction. By comparing nano- and micro-scale indentation results, we also reveal an effect of hierarchical architecture on the mechanical properties of coral skeletons and hypothesize that crystal packing and orientation result in microscale anisotropy. In contrast to previous findings, we demonstrate that mechanical and crystallographic properties of coral skeletons can vary between surface planes, within surface planes, and at different analytical scales. These results improve our understanding of biomineralization and the effects of scale and direction on how biomineral structures respond to environmental stimuli.
Assuntos
Antozoários , Ecossistema , Animais , Anisotropia , Módulo de Elasticidade , DurezaRESUMO
AIM: To compare peri-operative outcomes of skin closure with octyl cyanoacrylate (OCA) skin adhesive (Dermabond) with or without subcuticular sutures after deep dermal suturing for implantable venous port placement closure. MATERIALS AND METHODS: Seven hundred and ninety-two single-lumen implantable venous port insertions for chemotherapy were reviewed from September 2019 to March 2021 in a retrospective single-centre study. Propensity-score matching by a 1:1 nearest neighbour algorithm was conducted to control for confounding baseline differences. Distances were determined by logistic regression. Propensity-score matching was performed based on the following variables: age at procedure, gender, race, operator's seniority, use of anchoring polypropylene suture (PROLENE), port model, and volume of intra-operative local analgesia. The primary outcome was wound dehiscence at the first follow-up (â¼1 week). RESULTS: The 792 port insertions were conducted in 302 males (38.1%), median age 63 years (IQR: 54-69). Of the 656 wounds closed with subcuticular sutures and skin adhesive, 136 were matched in a 1:1 fashion against procedures closed without a subcuticular suture. No significant differences were demonstrated in pain scores, bleeding, swelling, bruising, fever, wound dehiscence, and discharge at postoperative day 1 (POD1) and at first follow-up between the groups (all p>0.05). Of note, no significant differences in wound dehiscence at first follow-up was found in both unmatched (p=0.133) and matched cohorts (McNemar-Bowker's χ2 = 1.167, p=0.761). CONCLUSION: These findings suggest that the omission of subcuticular sutures during implantable venous port closure may not compromise peri-operative outcomes when OCA skin adhesives were used.
Assuntos
Neoplasias , Adesivos Teciduais , Adesivos , Cianoacrilatos/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/tratamento farmacológico , Complicações Pós-Operatórias , Estudos Prospectivos , Estudos Retrospectivos , Suturas , Adesivos Teciduais/uso terapêutico , CicatrizaçãoRESUMO
BACKGROUND: Major depressive disorder (MDD) is a global public health concern that is notably underdiagnosed and undertreated due to its complexity and subjective diagnostic methods. A holistic diagnostic procedure, which sufficiently considers all possible contributors to MDD symptoms, would improve MDD diagnosis and treatment. This study aims to explore whether personality and coping styles can predict MDD status and differentiate between depressed patients and healthy individuals. METHODS: Seventy healthy controls (N = 54 females) were matched to 70 MDD patients for age, sex, ethnicity, and years of education. MDD severity was measured using the Hamilton Depression Rating Scale, while personality traits and coping styles were measured by the Ten-Item Personality (TIPI) and Brief COPE questionnaires, respectively. Logistic regression analyses were conducted to investigate the diagnostic and predictive potential of personality and coping styles. Receiver operating characteristic (ROC) analyses were also conducted to examine their discriminative ability to distinguish between depressed and healthy individuals. RESULTS: Introversion, lack of organisation skills, and neuroticism were statistically significant in predicting MDD status. Dysfunctional coping strategies, such as denial and self-blame, were also shown to significantly predict MDD status. ROC analyses found both the TIPI questionnaire (AUC = 0.90), and dysfunctional coping (as measured by Brief COPE) (AUC = 0.90) to be excellent predictors of MDD. CONCLUSIONS: Our findings demonstrate the diagnostic and predictive potential of personality and coping styles for MDD in the clinical setting. They also demonstrate the remarkable ability of personality and coping styles to differentiate between depressed patients and healthy controls.
Assuntos
Transtorno Depressivo Maior , Adaptação Psicológica , Transtorno Depressivo Maior/diagnóstico , Feminino , Humanos , Masculino , Personalidade , Transtornos da Personalidade , Inventário de PersonalidadeRESUMO
AIM: The aim of this work was to examine the efficacy of oral metronidazole in reducing posthaemorrhoidectomy pain versus placebo. METHOD: Forty patients were randomized to either metronidazole and standard care or placebo and standard care (21 metronidazole, 19 placebo) in a double-blinded, randomized controlled trial. The main outcome measure was posthaemorrhoidectomy pain scores over 21 days, measured on a 10-point Likert scale. RESULTS: There were no significant differences between groups with regards to age, gender, smoking status, self-reported general health or quality of life, haemorrhoid-related pain, haemorrhoid-related impact on quality of life, reported satisfaction with surgery, experience of surgery, median overall pain score or likelihood of recommending surgery to others. For reported median worst pain scores and defaecation-related pain, a trend to significance was identified between groups on days 16 and 18-21, with the metronidazole group reporting less pain. However, these differences were not significant when prespecified Bonferroni correction criteria were used. Using multilevel mixed effects modelling, the impact of time on median worst pain score was identified to be highly significant (P < 0.0001) whereas treatment allocation (placebo versus metronidazole) did not significantly affect the improvement in patients' reported pain (P = 0.8837). CONCLUSION: Our data do not support the hypothesis that postoperative metronidazole has a clinically meaningful effect on posthaemorrhoidectomy pain. This study adds to the previous literature, and implies that it should not be routinely used as an adjunct to analgesia.
Assuntos
Hemorroidectomia , Hemorroidas , Método Duplo-Cego , Hemorroidectomia/efeitos adversos , Hemorroidas/complicações , Hemorroidas/cirurgia , Humanos , Metronidazol/uso terapêutico , Dor Pós-Operatória/tratamento farmacológico , Dor Pós-Operatória/etiologia , Qualidade de VidaRESUMO
BACKGROUND: Staphylococcus aureas bacteraemia can spread to cause endocartitis, spondylodiscitis or infection of vascular or joint prostheses. Endogenous endophtalmitis is a serious complication which may result in permanent visual loss of the affected eye. Treatment consists of intra-ocular injection of antibiotics or a vitrectomy. CASE DESCRIPTION: A 79-year-old man attended the emergency department because of septic arthritis. Blood cultures were positive for a S. aureus bacteraemia. On the second day of admission he developed a blurred vision and he was diagnosed with an endophtalmitis. The patient was referred to an academic hospital for treatment with intra-ocular antibiotics. After treatment his vision improved again. CONCLUSION: Visual complaints should be taken seriously when a patient has a proven S. aureus bacteraemia. Infectious disease consultation may accelerate early recognition, referral and treatment. When endophtalmitis is suspected, it is essential to refer the patient to a treatment centre where intra-ocular antibiotics can be administered.
Assuntos
Bacteriemia/microbiologia , Infecções Oculares Bacterianas/microbiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus , Transtornos da Visão/microbiologia , Idoso , Antibacterianos/uso terapêutico , Artrite Infecciosa/tratamento farmacológico , Artrite Infecciosa/microbiologia , Bacteriemia/tratamento farmacológico , Infecções Oculares Bacterianas/tratamento farmacológico , Humanos , Masculino , Infecções Estafilocócicas/tratamento farmacológico , Transtornos da Visão/tratamento farmacológicoRESUMO
The aim of this article is to show the way to get both, exact and analytical approximate solutions for certain variational problems with moving boundaries but without resorting to Euler formalism at all, for which we propose two methods: the Moving Boundary Conditions Without Employing Transversality Conditions (MWTC) and the Moving Boundary Condition Employing Transversality Conditions (METC). It is worthwhile to mention that the first of them avoids the concept of transversality condition, which is basic for this kind of problems, from the point of view of the known Euler formalism. While it is true that the second method will utilize the above mentioned conditions, it will do through a systematic elementary procedure, easy to apply and recall; in addition, it will be seen that the Generalized Bernoulli Method (GBM) will turn out to be a fundamental tool in order to achieve these objectives.
RESUMO
HYPOTHESIS: Marine biofouling is a global, longstanding problem for maritime industries and coastal areas arising from the attachment of fouling organisms onto solid immersed surfaces. Slippery Liquid Infused Porous Surfaces (SLIPS) have recently shown promising capacity to combat marine biofouling. In most SLIPS coatings, the lubricant is a silicone/fluorinated-based synthetic component that may not be fully compatible with the marine life. We hypothesized that eco-friendly biolubricants could be used to replace synthetic lubricants in SLIPS for marine anti-fouling. EXPERIMENTS: We developed SLIPS coatings using oleic acid (OA) and methyl oleate (MO) as infusing phases. The infusion efficiency was verified with confocal microscopy, surface spectroscopy, wetting efficiency, and nanocontact mechanics. Using green mussels as a model organism, we tested the anti-fouling performance of the biolubricant infused SLIPS and verified its non-cytotoxicity against fish gill cells. FINDINGS: We find that UV-treated PDMS infused with MO gives the most uniform infused film, in agreement with the lowest interfacial energy among all surface/biolubricants produced. These surfaces exhibit efficient anti-fouling properties, as defined by the lowest number of mussel adhesive threads attached to the surface as well as by the smallest surface/thread adhesion strength. We find a direct correlation between anti-fouling performance and the substrate/biolubricant interfacial energy.
Assuntos
Incrustação Biológica/prevenção & controle , Ácido Oleico/farmacologia , Ácidos Oleicos/farmacologia , Ácido Oleico/química , Ácidos Oleicos/química , Tamanho da Partícula , Silicones/química , Silicones/farmacologia , Propriedades de SuperfícieRESUMO
AIM: Diabetes in young adulthood has been associated with poor outcomes. Self-management is fundamental to good diabetes care, and self-management interventions have been found to improve outcomes in older adults. We performed a systematic review and meta-analysis to assess the effectiveness of self-management interventions in young adults (aged 15-39 years) with type 1 or type 2 diabetes. METHODS: We searched five databases and two clinical trial registries from 2003 to February 2019, without language restrictions. We included randomized controlled trials (RCTs) comparing the effectiveness of self-management interventions with usual care or enhanced usual care in young adults. Outcomes of interest included clinical outcomes, psychological health, self-care behaviours, diabetes knowledge and self-efficacy. Pairwise meta-analysis was conducted using a random effects model and quality of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) criteria. We followed Cochrane gold standard systematic review methodology and reported this systematic review according to PRISMA guidelines. The protocol was registered with PROSEPRO (CRD42018110868). RESULTS: In total, 13 studies (1002 participants) were included. Meta-analysis showed no difference between self-management interventions and controls in post-intervention HbA1c levels, BMI, depression, diabetes-related distress, overall self-care, diabetes knowledge and self-efficacy. Quality of evidence ranged from very low to moderate due to study limitations, inconsistency and imprecision. CONCLUSIONS: Current self-management interventions did not improve outcomes in young adults with diabetes. Our findings, which contrast with those from systematic reviews in older adults, highlight the need for the development of more effective interventions for young adults with diabetes.
Assuntos
Diabetes Mellitus Tipo 1/terapia , Diabetes Mellitus Tipo 2/terapia , Autogestão/métodos , Adolescente , Adulto , Índice de Massa Corporal , Depressão/psicologia , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/psicologia , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/psicologia , Hemoglobinas Glicadas/metabolismo , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Angústia Psicológica , Autocuidado , Autoeficácia , Adulto JovemRESUMO
Schistosomiasis japonica is one of seven NTDs endemic in the Philippines that continues to threaten public health in the country. The causative agent, the blood fluke Schistosoma japonicum, uses an amphibious snail Oncomelania hupensis quadrasi which can harbor larval stages that multiply asexually, eventually producing the infective cercariae which are shed into the water. Contamination of freshwater bodies inhabited by the snail intermediate host occurs through release of human and animal feces containing S. japonicum eggs. Miracidia hatching from these eggs subsequently infect the snails that inhabit these water bodies. The degree of fecal contamination can vary across snail sites and influences snail infection rates in these sites. In this study, conventional malacological surveys using intensive manual search for snails were conducted from 2015 to 2016 in seven selected endemic provinces, namely Leyte and Bohol in the Visayas and Surigao del Norte, Agusan del Sur, Bukidnon, Lanao del Norte and Compostela Valley in Mindanao. A total of 6,279 O. hupensis quadrasi snails were collected from 38 snail sites. The municipality of Trento in Agusan del Sur recorded the highest number of snail sites (7) that yielded O. hupensis quadrasi snails while only one snail site was found positive for O. hupensis quadrasi snails in Kapatagan in Lanao del Norte and Talibon in Bohol. Alegria in Surigao del Norte yielded the highest number of snail sites (5) that were found to harbor snails positive for S. japonicum infection. The snail infection rates in this municipality ranged from 0.43% to 14.71%. None of the snails collected from Talibon in Bohol was infected. Bohol is the only province among the 28 schistosomiasis-endemic provinces which has reached near elimination status. Snail infection rates were found to vary considerably across snail sites, which could be due to the degree of fecal contamination of the snail sites and their connectivity to water that can serve as contamination source.
RESUMO
@#Schistosomiasis japonica is one of seven NTDs endemic in the Philippines that continues to threaten public health in the country. The causative agent, the blood fluke Schistosoma japonicum, uses an amphibious snail Oncomelania hupensis quadrasi which can harbor larval stages that multiply asexually, eventually producing the infective cercariae which are shed into the water. Contamination of freshwater bodies inhabited by the snail intermediate host occurs through release of human and animal feces containing S. japonicum eggs. Miracidia hatching from these eggs subsequently infect the snails that inhabit these water bodies. The degree of fecal contamination can vary across snail sites and influences snail infection rates in these sites. In this study, conventional malacological surveys using intensive manual search for snails were conducted from 2015 to 2016 in seven selected endemic provinces, namely Leyte and Bohol in the Visayas and Surigao del Norte, Agusan del Sur, Bukidnon, Lanao del Norte and Compostela Valley in Mindanao. A total of 6,279 O. hupensis quadrasi snails were collected from 38 snail sites. The municipality of Trento in Agusan del Sur recorded the highest number of snail sites (7) that yielded O. hupensis quadrasi snails while only one snail site was found positive for O. hupensis quadrasi snails in Kapatagan in Lanao del Norte and Talibon in Bohol. Alegria in Surigao del Norte yielded the highest number of snail sites (5) that were found to harbor snails positive for S. japonicum infection. The snail infection rates in this municipality ranged from 0.43% to 14.71%. None of the snails collected from Talibon in Bohol was infected. Bohol is the only province among the 28 schistosomiasis-endemic provinces which has reached near elimination status. Snail infection rates were found to vary considerably across snail sites, which could be due to the degree of fecal contamination of the snail sites and their connectivity to water that can serve as contamination source.
RESUMO
The Arthropoda, the largest phylum of the Animal Kingdom, have successfully evolved to survive various ecological constraints under a wide range of environmental conditions. Central to this survival are the structural designs developed in their exoskeletons and their raptorial appendages for protection and hunting. One such example, the pistol shrimp, is a shallow-water crustacean that is well-known for its aggressive hunting behavior, using its snapper claw to trigger the nucleation of cavitation bubbles that strike targets. In this study, we conducted a multi-scale structural/nanomechanics relationship study of this biotool to analyze its mechanical response to contact stresses. We found that the pistol shrimp snapper claw, which exhibits the capacity to emit a high-velocity water jet during rapid closure actions, is more brittle than other mineralized biotools, exhibiting accelerated wear damage under contact stresses. However, due to an angular offset between the dactylus and pollex of the snapper claw, the appendage never engages in any mechanical contact during the snapping action. This feature is in stark contrast to that reported in other fast raptorial appendages of crustaceans, notably the mantis shrimp dactyl club, which is designed to shatter close range targets in contact mode and exhibits a superior resistance to contact damage and wear. These findings suggest that adaptation of hunting appendages goes beyond their macroscopic morphology, and that multi-scale structural design concomitantly adapted to function, with enhanced structural complexification for tools that are subjected to more intense contact stresses. STATEMENT OF SIGNIFICANCE: The evolution success of crustaceans is largely due to the diversification of their mineralized exoskeletons and hunting appendages, which exhibit a large palette of morphometric characteristics that have adapted to meet particular functions. We explored the "snapper claw" of the pistol shrimp, which is used to generate cavitation bubbles and strike prey. Our multi-scale structure-property relationship study reveals that the snapper claw is more brittle than other fast raptorial appendages - such as the stomatopod dactyl club - because it is not directly subjected to direct contact forces during action. This study implies that when higher mechanical stresses are needed to meet the function, the internal structure is built of a more complex architecture that allows to mitigate internal structural damage.
Assuntos
Exoesqueleto/fisiologia , Crustáceos/fisiologia , Animais , Fenômenos Biomecânicos , Extremidades , Microscopia Eletrônica , Especificidade da Espécie , Análise Espectral Raman , Estresse Mecânico , Propriedades de Superfície , Difração de Raios X , Microtomografia por Raio-XRESUMO
Parrotfish (Scaridae) feed by biting stony corals. To investigate how their teeth endure the associated contact stresses, we examine the chemical composition, nano- and microscale structure, and the mechanical properties of the steephead parrotfish Chlorurus microrhinos tooth. Its enameloid is a fluorapatite (Ca5(PO4)3F) biomineral with outstanding mechanical characteristics: the mean elastic modulus is 124 GPa, and the mean hardness near the biting surface is 7.3 GPa, making this one of the stiffest and hardest biominerals measured; the mean indentation yield strength is above 6 GPa, and the mean fracture toughness is â¼2.5 MPa·m1/2, relatively high for a highly mineralized material. This combination of properties results in high abrasion resistance. Fluorapatite X-ray absorption spectroscopy exhibits linear dichroism at the Ca L-edge, an effect that makes peak intensities vary with crystal orientation, under linearly polarized X-ray illumination. This observation enables polarization-dependent imaging contrast mapping of apatite, a method to quantitatively measure and display nanocrystal orientations in large, pristine arrays of nano- and microcrystalline structures. Parrotfish enameloid consists of 100 nm-wide, microns long crystals co-oriented and assembled into bundles interwoven as the warp and the weave in fabric and therefore termed fibers here. These fibers gradually decrease in average diameter from 5 µm at the back to 2 µm at the tip of the tooth. Intriguingly, this size decrease is spatially correlated with an increase in hardness.
Assuntos
Antozoários/química , Apatitas/química , Módulo de Elasticidade , Dente/química , Animais , Fenômenos Biomecânicos , Tamanho da Partícula , PerciformesRESUMO
PURPOSE: The purpose of this study is to confirm a difference in the first-trimester screen maternal biochemistry and false-positive rates (FPR) between pregnancies conceived spontaneously and those conceived via assisted reproductive technologies (ART). METHODS: Retrospective analysis of the complete population of women (17,889 pregnancies) who had undergone first-trimester screening between January 2004 and September 2009 at three private ultrasound clinics in Queensland, Australia was used in the study. The age, gestation, method of conception, ultrasound markers, biochemistry markers (PAPP-A, fß-hCG), and type of biochemical analyzer platform (Brahms Kryptor, Immulite 2000) data was collated. Univariate analysis of variance (ANOVA), Spearman's rank nonparametric correlation analysis, and Binary Logistic Regression analysis were used to analyze data. Spontaneous pregnancies were used as controls. Results were considered significant when the p value was less than 0.05. RESULTS: After exclusions, 16,363 singleton pregnancies, including 1543 conceived via ART, were analyzed. Results from the two biochemistry platforms, Brahms Kryptor and Immulite 2000 were significantly different (p < 0.001); thus, the data was divided for analysis purposes. PAPP-A was universally significantly lower in IVF pregnancies compared to spontaneously conceived pregnancies (p < 0.001). Using the Brahms Kryptor platform, ICSI was associated with significantly decreased PAPP-A (p < 0.046), and a significantly increased FPR (p = 0.012). CONCLUSIONS: Consistent with previous studies IVF pregnancies had significantly lower PAPP-A levels supporting the need to appropriately adjust the combined first-trimester screening (cFTS) risk algorithm for IVF conceptions. The Brahms Kryptor and Immulite 2000 platforms are significantly different; however, the universally lower PAPP-A findings support the hypothesis that the lower PAPP-A is due to a biological cause.
Assuntos
Testes de Gravidez/métodos , Proteína Plasmática A Associada à Gravidez/análise , Técnicas de Reprodução Assistida , Adolescente , Adulto , Biomarcadores , Gonadotropina Coriônica/sangue , Estudos de Coortes , Reações Falso-Positivas , Feminino , Fertilização in vitro , Humanos , Pessoa de Meia-Idade , Gravidez , Primeiro Trimestre da Gravidez , Análise de Regressão , Injeções de Esperma IntracitoplásmicasRESUMO
BACKGROUND: While domiciliary non-invasive ventilation (NIV) was initially used in the treatment of respiratory failure resulting from chest wall deformity, the main indication is now chronic obstructive pulmonary disease (COPD) with recurrent exacerbations associated with type 2 respiratory failure. A longitudinal study of domiciliary NIV provides insights into the evolution of this treatment in the west of Ireland. METHODS: The cohort of patients receiving new prescriptions for domiciliary NIV from Galway University Hospital from 2000 to 2012 was reviewed using study coordinator chart reviews and telephone follow-ups. RESULTS: In total, 161 patients were identified. Prescriptions for domiciliary NIV increased from 2 in 2000 to 35 in 2012. The most common indication between 2000 and 2006 was obesity hypoventilation syndrome (OHS), changing to COPD between 2007 and 2012. There were significantly higher mortality rates in COPD and neuromuscular disease at 1- and 3-year follow-up compared to OHS and chest wall disease. Patients with chest wall disease had most survival years (7.33 ± 5.51) following initiation of domiciliary NIV when compared to patients with OHS (5.50 ± 3.70) and COPD (3.03 ± 1.89) and patients with neuromuscular disease (2.50 ± 2.01). CONCLUSIONS: Domiciliary NIV use increased significantly in the West of Ireland from 2000 to 2012. There has been a shift in prescribing toward COPD. Survival rates for COPD on NIV are relatively short in contrast to patients with OHS and chest wall disease. Improved understanding of the benefits of NIV will allow physicians to better determine appropriate and cost-effective use in the future.