X‑ray Linear Dichroism in Apatite Stifler, Cayla A; Wittig, Nina Kølln; Sassi, Michel ...
Journal of the American Chemical Society,
09/2018, Letnik:
140, Številka:
37
Journal Article
Recenzirano
Odprti dostop
The recent observation in parrotfish teeth of X-ray linear dichroism motivated an in-depth investigation into this spectroscopic effect in various apatite crystals, including geologic hydroxyapatite ...(Ca5(PO4)3OH), fluorapatite (Ca5(PO4)3F), and their biogenic counterparts in human bone, mouse enamel, and in parrotfish bone, dentin, and enameloid, the equivalent of dental enamel in certain fish. These data are important because they now enable visualization of the nano- to microscale structure of apatite crystals in teeth and bone. Polarization-dependent imaging contrast (PIC) maps of lamellar bone, obtained with a new method that minimizes space-charge and charging effects, show the expected rotating apatite crystal orientations. PIC maps of mouse enamel reveal a complex arrangement of hydroxyapatite crystals perpendicular to the dentin–enamel junction, with rods arranged in a decussation pattern in inner enamel and nearly parallel to one another in outer enamel. In both inner and outer enamel crystal c-axes are not always aligned with the rod elongation direction.
We investigated if cardiac spatial repolarization heterogeneity might be associated with an increased risk of death in patients with chronic Chagas disease.
Repolarization heterogeneity was assessed ...using the V-index, a recently introduced metric founded on a biophysical model of the ECG. This metric provides an estimate of the standard deviation of the repolarization times across the heart. We analyzed 113 patients (aged 21- 67 years) enrolled between 1998 and 1999 who had a known serological status showing positive reactions to Trypanosoma cruzi. Fourteen subjects died during a 10-year follow-up period.
The V-index was significantly lower in survivor (S) than in non-survivor (NS) subjects (S: 31.2 ± 13.3 ms vs NS: 41.2 ± 18.6 ms, single-tail t-test: p = 0.009, single-tail Wilcoxon rank sum test: p = 0.029). A V-index larger than 36.3 ms was related to a significantly higher risk of death in a univariate Cox proportional-hazards analysis (hazard ratio, HR = 5.34, p = 0.0046). In addition, V-index > 36.3 ms retained its prognostic value in a multivariate Cox proportional-hazards analysis after adjustment for other three clinical variables (left ventricular ejection factor < 0.50, QRS duration > 133 ms, ventricular tachycardia during stress testing or 24 hours Holter) and for T-wave amplitude variability > 30 μV, even using shrinkage, a statistical procedure that protects against over-fitting due to small sample size.
The study showed that an increased dispersion of repolarization times in patients with Chagas disease, as measured by the V-index, is significantly correlated with the risk of death in a univariate survival analysis. The V-index captures prognostic information not immediately available from the analysis of other established risk factors.
Regorafenib (REG) is approved for the treatment of metastatic colorectal cancer, but has modest survival benefit and associated toxicities. Robust predictive/early response biomarkers to aid patient ...stratification are outstanding. We have exploited biological pathway analyses in a patient-derived xenograft (PDX) trial to study REG response mechanisms and elucidate putative biomarkers.
Molecularly subtyped PDXs were annotated for REG response. Subtyping was based on gene expression (CMS, consensus molecular subtype) and copy-number alteration (CNA). Baseline tumor vascularization, apoptosis, and proliferation signatures were studied to identify predictive biomarkers within subtypes. Phospho-proteomic analysis was used to identify novel classifiers. Supervised RNA sequencing analysis was performed on PDXs that progressed, or did not progress, following REG treatment.
Improved REG response was observed in CMS4, although intra-subtype response was variable. Tumor vascularity did not correlate with outcome. In CMS4 tumors, reduced proliferation and higher sensitivity to apoptosis at baseline correlated with response. Reverse phase protein array (RPPA) analysis revealed 4 phospho-proteomic clusters, one of which was enriched with non-progressor models. A classification decision tree trained on RPPA- and CMS-based assignments discriminated non-progressors from progressors with 92% overall accuracy (97% sensitivity, 67% specificity). Supervised RNA sequencing revealed that higher basal
expression is associated with REG resistance.
Subtype classification systems represent canonical "
" (starting points) to support REG biomarker identification, and provide a platform to identify resistance mechanisms and novel contexts of vulnerability. Incorporating functional characterization of biological systems may optimize the biomarker identification process for multitargeted kinase inhibitors.
Long-acting reversible contraceptives (LARC) represent an especially effective kind of post-abortion contraception. We aimed at assessing satisfaction, discontinuation, efficacy, and tolerability ...associated with either levonorgestrel intrauterine device (L-IUCD), the copper intrauterine device (C-IUCD) and implant (IMP) after termination of pregnancy (TOP). We recorded baseline data about the patients and performed phone surveys at 3, 6 and 12 months after insertion to assess the bleeding profile. Furthermore, women were inquired about possible adverse events, satisfaction, and discontinuation at 12 months after insertion. LARC continuers (>12 months after TOP) were divided into three groups: L-IUCD (n = 47), C-IUCD (n = 6) and IMP (n = 36). Satisfaction rates among L-IUCD users were higher than among IMP users (100% vs. 72.2%, p < .05). A higher, yet not significant, share of patients decided to withdraw contraception in IMP group (3.6% in IUCD group and 12.2% in IMP group). The bleeding profile was significantly more favorable among L-IUCD users than among IMP users. Finally, the reported rate of treatment-associated adverse events did not differ significantly among the groups. L-IUCD insertion after TOP is associated with higher satisfaction and lower discontinuation rates than IMP. Such pattern could be attributed to a more favorable bleeding profile.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Many surgeons routinely place intraperitoneal drains after elective colorectal surgery. However, enhanced recovery after surgery guidelines recommend against their routine use owing to a lack of ...clear clinical benefit. This study aimed to describe international variation in intraperitoneal drain placement and the safety of this practice.
COMPASS (COMPlicAted intra-abdominal collectionS after colorectal Surgery) was a prospective, international, cohort study which enrolled consecutive adults undergoing elective colorectal surgery (February to March 2020). The primary outcome was the rate of intraperitoneal drain placement. Secondary outcomes included: rate and time to diagnosis of postoperative intraperitoneal collections; rate of surgical site infections (SSIs); time to discharge; and 30-day major postoperative complications (Clavien-Dindo grade at least III). After propensity score matching, multivariable logistic regression and Cox proportional hazards regression were used to estimate the independent association of the secondary outcomes with drain placement.
Overall, 1805 patients from 22 countries were included (798 women, 44.2 per cent; median age 67.0 years). The drain insertion rate was 51.9 per cent (937 patients). After matching, drains were not associated with reduced rates (odds ratio (OR) 1.33, 95 per cent c.i. 0.79 to 2.23; P = 0.287) or earlier detection (hazard ratio (HR) 0.87, 0.33 to 2.31; P = 0.780) of collections. Although not associated with worse major postoperative complications (OR 1.09, 0.68 to 1.75; P = 0.709), drains were associated with delayed hospital discharge (HR 0.58, 0.52 to 0.66; P < 0.001) and an increased risk of SSIs (OR 2.47, 1.50 to 4.05; P < 0.001).
Intraperitoneal drain placement after elective colorectal surgery is not associated with earlier detection of postoperative collections, but prolongs hospital stay and increases SSI risk.
This paper aims to assess variations in self-reported morbidity between men and women using six different measures of reported illness. The cross-sectional study was conducted in the municipality of ...Rio Grande, southern Brazil. Demographic, socioeconomic, and morbidity data were collected from a probabilistic sample of 1,260 persons aged 15 years or over, using a specific questionnaire. Statistical analysis included a multivariate Poisson regression analysis. Prevalence Ratios (PR) with 95% confidence intervals (95%CI) were calculated. After adjusting for some confounding variables (age, race, unemployment, marital status, income, social class, and education), women showed greater risk of any symptom (PR = 3.21; 95%CI: 2.71-3.83), three or more symptoms (PR = 4.22; 95%CI: 2.97-5.98), potentially serious symptoms (PR = 1.75; 95%CI: 1.31-2.34), poor/fair health (PR = 1.78; 95%CI: 1.37-2.32), and minor psychiatric disorders (PR = 1.76; 95%CI: 1.31-2.37). The study revealed dissimilarity in self-reported morbidity between men and women in southern Brazil, but with different degrees depending on type of morbidity. This excess can be explained by gender difference in health-seeking behavior for perceiving or reporting health problems.
In this paper, experimental and numerical studies are made to investigate local thermal equilibrium in a microwave plasma torch at atmospheric pressure for hydrogen and carbon black production from ...methane dissociation. The microwave induced plasma can be operated up to 2 kW power at 2.45 GHz frequency. Methane is dissociated in argon, air or nitrogen plasma and optical emission spectroscopy is used to characterize the plasma. C2, CN and OH ro-vibrational bands are used for rotational and vibrational temperature estimation while stark broadening of H-line is used for electron temperature calculation. Temperatures are determined at varying operating parameters of microwave power, axial gas flow rate, and methane flow rate. The rotational (heavy particle), vibrational, and electron temperatures are found to be equal to 5000 ± 500 K. The plasma is thus at local thermodynamic equilibrium.
•Atmospheric-pressure microwave plasma torch for hydrogen production.•Spontaneous optical emission spectroscopy characterization.•Rotational, vibrational, electronic and plasma gas temperature.•Local thermodynamic equilibrium in an argon/methane MW plasma.•Thermal plasma kinetics of methane dissociation.
It is recognized that the resolved tropical wave spectrum can vary considerably among general circulation models (GCMs) and that these differences can have an important impact on the simulated ...climate. A comprehensive comparison of low-latitude waves is presented for the December-January-February period using high-frequency data from nine GCMs participating in the GCM Reality Intel-comparison Project for Stratospheric Processes and Their Role in Climate (GRIPS; SPARC). Quantitative measures of the wavenumber-frequency structure of resolved waves and their impacts on the zonal mean circulation are given. Space-time spectral analysis reveals that the wave spectrum throughout the middle atmosphere is linked to the variability of convective precipitation, which is determined by the parameterized convection. The variability of the precipitation spectrum differs by more than an order of magnitude among the models, with additional changes in the spectral distribution (especially the frequency). These differences can be explained primarily by the choice of different cumulus parameterizations: quasi-equilibrium mass-flux schemes tend to produce small variability, while the moist-convective adjustment scheme is the most active. Comparison with observational estimates of precipitation variability suggests that the model values are scattered around the observational estimates. Among the models, only those that produce the largest precipitation variability can reproduce the equatorial quasi-biennial oscillation (QBO). This implies that in the real atmosphere, the forcing from the waves, which are resolvable with the typical resolutions of present-day GCMs, is insufficient to drive the QBO. Parameterized cumulus convection also impacts the nonmigrating tides in the equatorial region. In most of the models, momentum transport by diurnal nonmigrating tides in the mesosphere is comparable to or larger than that by planetary-scale Kelvin waves, being more significant than has been thought. It is shown that the westerly accelerations in the equatorial semi-annual oscillation in the models examined are driven mainly by gravity waves with periods shorter than 3 days, with some contribution from parameterized gravity waves, and that the contribution from the wavenumber1 Kelvin waves is negligible. These results provide a state-of-the-art assessment of the links between convective parameterizations and middle-atmospheric waves in present-day middle-atmosphere climate models. PUBLICATION ABSTRACT
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
La utilización de los servicios de salud está determinada por diversos factores. Con la finalidad de estudiar cuales son los factores más importantes y consistentes, fue realizada una revisión ...sistemática entre los años 1970 y 1999. Se encontró que la media de consultas, la proporción de personas que consultan y la proporción que concentra el mayor número de consultas fueron similares. Entre los factores demográficos, niños, mujeres en edad fértil y ancianos utilizan más los servicios. Entre los socioeconómicos, la clase social baja y el grupo con menos educación se asociaron con la utilización. El mayor uso está mediado por una mayor necesidad en salud. Pero, según del tipo de sistema, estos grupos menos favorecidos pueden recibir una insuficiente atención. La necesidad en salud es uno de los factores más importantes y, si se desea analizar la equidad del sistema, es necesario tener en cuenta el padrón de utilización entre los grupos sociales para el nivel de mayor necesidad en salud. Entre los factores relacionados a los servicios de salud, tener un médico definido determina una utilización más adecuada. Esto puede servir para atenuar las diferencias en la atención médica entre los diferentes grupos sociales. Finalmente, se propone una jerarquía para los factores relacionados.
Intraperitoneal drains are often placed during emergency colorectal surgery. However, there is a lack of evidence supporting their use. This study aimed to describe the efficacy and safety of ...intraperitoneal drain placement after emergency colorectal surgery.
COMPlicAted intra-abdominal collectionS after colorectal Surgery (COMPASS) is a prospective, international, cohort study into which consecutive adult patients undergoing emergency colorectal surgery were enrolled (from 3 February 2020 to 8 March 2020). The primary outcome was the rate of intraperitoneal drain placement. Secondary outcomes included rate and time-to-diagnosis of postoperative intraperitoneal collections, rate of surgical site infections (SSIs), time to discharge and 30-day major postoperative complications (Clavien-Dindo III-V). Multivariable logistic and Cox proportional hazards regressions were used to estimate the independent association of the outcomes with drain placement.
Some 725 patients (median age 68.0 years; 349 48.1% women) from 22 countries were included. The drain insertion rate was 53.7% (389 patients). Following multivariable adjustment, drains were not significantly associated with reduced rates (odds ratio OR = 1.56, 95% CI: 0.48-5.02, p = 0.457) or earlier detection (hazard ratio HR = 1.07, 95% CI: 0.61-1.90, p = 0.805) of collections. Drains were not significantly associated with worse major postoperative complications (OR = 1.26, 95% CI: 0.67-2.36, p = 0.478), delayed hospital discharge (HR = 1.11, 95% CI: 0.91-1.36, p = 0.303) or increased risk of SSIs (OR = 1.61, 95% CI: 0.87-2.99, p = 0.128).
This is the first study investigating placement of intraperitoneal drains following emergency colorectal surgery. The safety and clinical benefit of drains remain uncertain. Equipoise exists for randomized trials to define the safety and efficacy of drains in emergency colorectal surgery.
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