14 research outputs found
Goodbye Hartmann trial: a prospective, international, multicenter, observational study on the current use of a surgical procedure developed a century ago
Background: Literature suggests colonic resection and primary anastomosis (RPA) instead of Hartmann's procedure (HP) for the treatment of left-sided colonic emergencies. We aim to evaluate the surgical options globally used to treat patients with acute left-sided colonic emergencies and the factors that leading to the choice of treatment, comparing HP and RPA. Methods: This is a prospective, international, multicenter, observational study registered on ClinicalTrials.gov. A total 1215 patients with left-sided colonic emergencies who required surgery were included from 204 centers during the period of March 1, 2020, to May 31, 2020. with a 1-year follow-up. Results: 564 patients (43.1%) were females. The mean age was 65.9 ± 15.6 years. HP was performed in 697 (57.3%) patients and RPA in 384 (31.6%) cases. Complicated acute diverticulitis was the most common cause of left-sided colonic emergencies (40.2%), followed by colorectal malignancy (36.6%). Severe complications (Clavien-Dindo ≥ 3b) were higher in the HP group (P < 0.001). 30-day mortality was higher in HP patients (13.7%), especially in case of bowel perforation and diffused peritonitis. 1-year follow-up showed no differences on ostomy reversal rate between HP and RPA. (P = 0.127). A backward likelihood logistic regression model showed that RPA was preferred in younger patients, having low ASA score (≤ 3), in case of large bowel obstruction, absence of colonic ischemia, longer time from admission to surgery, operating early at the day working hours, by a surgeon who performed more than 50 colorectal resections. Conclusions: After 100 years since the first Hartmann's procedure, HP remains the most common treatment for left-sided colorectal emergencies. Treatment's choice depends on patient characteristics, the time of surgery and the experience of the surgeon. RPA should be considered as the gold standard for surgery, with HP being an exception
Infected pancreatic necrosis: outcomes and clinical predictors of mortality. A post hoc analysis of the MANCTRA-1 international study
: The identification of high-risk patients in the early stages of infected pancreatic necrosis (IPN) is critical, because it could help the clinicians to adopt more effective management strategies. We conducted a post hoc analysis of the MANCTRA-1 international study to assess the association between clinical risk factors and mortality among adult patients with IPN. Univariable and multivariable logistic regression models were used to identify prognostic factors of mortality. We identified 247 consecutive patients with IPN hospitalised between January 2019 and December 2020. History of uncontrolled arterial hypertension (p = 0.032; 95% CI 1.135-15.882; aOR 4.245), qSOFA (p = 0.005; 95% CI 1.359-5.879; aOR 2.828), renal failure (p = 0.022; 95% CI 1.138-5.442; aOR 2.489), and haemodynamic failure (p = 0.018; 95% CI 1.184-5.978; aOR 2.661), were identified as independent predictors of mortality in IPN patients. Cholangitis (p = 0.003; 95% CI 1.598-9.930; aOR 3.983), abdominal compartment syndrome (p = 0.032; 95% CI 1.090-6.967; aOR 2.735), and gastrointestinal/intra-abdominal bleeding (p = 0.009; 95% CI 1.286-5.712; aOR 2.710) were independently associated with the risk of mortality. Upfront open surgical necrosectomy was strongly associated with the risk of mortality (p < 0.001; 95% CI 1.912-7.442; aOR 3.772), whereas endoscopic drainage of pancreatic necrosis (p = 0.018; 95% CI 0.138-0.834; aOR 0.339) and enteral nutrition (p = 0.003; 95% CI 0.143-0.716; aOR 0.320) were found as protective factors. Organ failure, acute cholangitis, and upfront open surgical necrosectomy were the most significant predictors of mortality. Our study confirmed that, even in a subgroup of particularly ill patients such as those with IPN, upfront open surgery should be avoided as much as possible. Study protocol registered in ClinicalTrials.Gov (I.D. Number NCT04747990)
Physicochemical and Thermodynamic Characterization of the Encapsulation of Methyl Jasmonate by Natural and Modified Cyclodextrins Using Reversed-Phase High-Pressure Liquid Chromatography
Although the combinations of methyl
jasmonate (MeJA) and cyclodextrins
(CDs) have been used by different authors to stimulate the production
of several metabolites, no study has been published about the possible
formation of MeJA–CD complexes when these two molecules are
added together to the reaction medium as elicitors. For this reason
and because knowledge of the possible complexation process of MeJA
with CD under different physicochemical conditions is essential if
these two molecules are to be used in cell cultures, this paper looks
at the complexation of MeJA with natural and modified CDs using a
reversed-phase high-pressure liquid chromatography (RP-HPLC) system.
The interaction of MeJA with β-CD was more efficient than with
α- and γ-CDs. However, a modified CD, HP-β-CD, was
the most effective of all of the CDs tested. Moreover, MeJA formed
complexes with CD with a 1:1 stoichiometry, and the formation constants
of these complexes were strongly dependent upon the temperature of
the mobile phase used but not the pH. To obtain information about
the mechanism of the affinity of MeJA for CD, the thermodynamic parameters
Δ<i>G</i>°, Δ<i>H</i>°,
and Δ<i>S</i>° were calculated. Finally, molecular
modeling studies were carried out to propose which molecular interactions
are established in the complexation process
Water-Dependent Micromechanical and Rheological Properties of Silica Colloidal Crystals Studied by Nanoindentation
Here we show the suitability of nanoindentation to study
in detail
the micromechanical response of silica colloidal crystals (CCs). The
sensitivity to displacements smaller than the submicrometer spheres
size, even resolving discrete events and superficial features, revealed
particulate features with analogies to atomic crystals. Significant
robustness, long-range structural deformation, and large energy dissipation
were found. Easily implemented temperature/rate-dependent nanoindentation
quantified the paramount role of adsorbed water endowing silica CCs
with properties of wet granular materials like viscoplasticity. A
novel “nongranular” CC was fabricated by substituting
capillary bridges with silica necks to directly test water-independent
mechanical response. Silica CCs, as specific (nanometric, ordered)
wet granular assemblies with well-defined configuration, may be useful
model systems for granular science and capillary cohesion at the nanoscale
Experimental Analysis and Numerical Modeling of a Shell and Tube Heat Storage Unit with Phase Change Materials
Thermal storages
are part of highly integrated energy systems.
The development of accurate and reduced models is critical for efficient
simulations on a system-level and the analysis of the storage design,
control, and integration. We present the experimental analysis and
numerical modeling of a lab-scale shell and tube latent heat thermal
energy storage (LHTES) unit with a (latent) storage capacity of about
10–15 kWh. The phase change material (PCM) is a high density
polyethylene (HD-PE) with phase change temperatures between 120 and
135 °C. An efficient 2D numeric storage model is derived which
accounts for design and material parameters of PCM, storage, and heat
transfer fluid (HTF). Different probability distribution functions
are used to model the PCM apparent specific heat capacity. From these
functions the state of charge (SOC) can be predicted, which indicates
the extent to which a LHTES is charged relative to storeable latent
heat. Model predictions are fitted to experimental data from thermophysical
measurements and from LHTES operation with partial and full charging/discharging.
The storage model agrees well with experimental results. However,
thermosphysical material analysis and storage operation indicated
that the temperature range of phase transition is noticeable affected
by storage loading operating condition, i.e., heating and cooling
rates, which is not considered in the model. With this simplification
it turns out that the model is limited by the quality of prediction
of internal storage PCM temperatures
Tamm Plasmon Resonance in Mesoporous Multilayers: Toward a Sensing Application
A novel optical sensor is proposed,
based on the normal-incidence
excitation of Tamm plasmons at the interface between a multilayer
of porous SiO<sub>2</sub> and TiO<sub>2</sub>, acting as a permeable
Bragg reflector, and a flat gold film. Transmittance spectra reveal
a sharp Tamm mode within the stop-band of the distributed Bragg reflector,
the spectral position of which was monitored upon exposure to various
solvents, demonstrating the sensitivity of the device to changes of
refractive index
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Remediation of Thirdhand Tobacco Smoke with Ozone: Probing Deep Reservoirs in Carpets
We assessed the efficacy of ozonation as an indoor remediation strategy by evaluating how a carpet serves as a sink and long-term source of thirdhand tobacco smoke (THS) while protecting contaminants absorbed in deep reservoirs by scavenging ozone. Specimens from unused carpet that was exposed to smoke in the lab ("fresh THS") and contaminated carpets retrieved from smokers' homes ("aged THS") were treated with 1000 ppb ozone in bench-scale tests. Nicotine was partially removed from fresh THS specimens by volatilization and oxidation, but it was not significantly eliminated from aged THS samples. By contrast, most of the 24 polycyclic aromatic hydrocarbons detected in both samples were partially removed by ozone. One of the home-aged carpets was installed in an 18 m3 room-sized chamber, where its nicotine emission rate was 950 ng day-1 m-2. In a typical home, such daily emissions could amount to a non-negligible fraction of the nicotine released by smoking one cigarette. The operation of a commercial ozone generator for a total duration of 156 min, reaching concentrations up to 10,000 ppb, did not significantly reduce the carpet nicotine loading (26-122 mg m-2). Ozone reacted primarily with carpet fibers, rather than with THS, leading to short-term emissions of aldehydes and aerosol particles. Hence, by being absorbed deeply into carpet fibers, THS constituents can be partially shielded from ozonation
Centimeter-Scale Synthesis of Ultrathin Layered MoO<sub>3</sub> by van der Waals Epitaxy
We
report on the large-scale synthesis of highly oriented ultrathin
MoO<sub>3</sub> layers using a simple and low-cost atmospheric pressure,
van der Waals epitaxy growth on muscovite mica substrates. By this
method, we are able to synthesize high quality centimeter-scale MoO<sub>3</sub> crystals with thicknesses ranging from 1.4 nm (two layers)
up to a few nanometers. The crystals can be easily transferred to
an arbitrary substrate (such as SiO<sub>2</sub>) by a deterministic
transfer method and be extensively characterized to demonstrate the
high quality of the resulting crystal. We also study the electronic
band structure of the material by density functional calculations.
Interestingly, the calculations demonstrate that bulk MoO<sub>3</sub> has a rather weak electronic interlayer interaction, and thus, it
presents a monolayer-like band structure. Finally, we demonstrate
the potential of this synthesis method for optoelectronic applications
by fabricating large-area field-effect devices (10 μm ×
110 μm in lateral dimensions) and find responsivities of 30
mA W<sup>–1</sup> for a laser power density of 13 mW cm<sup>–2</sup> in the UV region of the spectrum and also as an electron
acceptor in a MoS<sub>2</sub>-based field-effect transistor