U ožujku 2020. godine vrata hrvatskih muzeja zatvorena su na nekoliko tjedana kako bi se spriječilo širenje bolesti COVID-19. Razdoblje fizičke zatvorenosti dodatno se produžilo za pojedine ...zagrebačke muzeje teško stradale u potresu. Nakon otvaranja, kao i u mnogim drugim muzejima u Europi i svijetu, fizičke posjete i dalje su smanjene i muzeji bilježe drastičan pad posjetitelja te financijske gubitke. Kao odgovor na trenutnu situaciju, s ciljem nastavka ispunjavanja svoje društvene, kulturne i obrazovne funkcije, muzeji su se okrenuli internetu i društvenim mrežama kao mjestima za dijalog s korisnicima, diseminaciju sadržaja i prezentaciju događanja koja se ne mogu fizički organizirati. Mnogi muzeji posvetili su se stvaranju internetskih resursa poput digitalnih izložbi, virtualnih tura, materijala za e-učenje, internetskih konferencija te se na različite načine i na različitim platformama nastoje povezati sa svojom publikom. Cilj ovog rada bio je istražiti kako su hrvatski muzeji korištenjem digitalnih medija prilagodili svoje usluge i sadržaje novim uvjetima poslovanja. U radu su analizirane i vrednovane aktivnosti muzeja na mrežnim stranicama i društvenim mrežama u godini dana od početka pandemije. Rezultati ukazuju na kvantitativno kao i kvalitativno bogatu internetsku prisutnost muzeja, koja bi mogla značiti početak nove ere u digitalnoj komunikaciji i diseminaciji baštinskih sadržaja. Istraživanje zaključuje da je digitalizacija aktivnosti muzeja nužna za buduću održivost muzejskih funkcija te potiče daljnja razmišljanja o smjeru digitalnog pristupa kulturi i baštini.
Abstract Background The Centers for Disease Control and Prevention reported that surgical site infections (SSIs) create a significant hospital burden. To date, few multi-institutional studies have ...been performed to evaluate the risk factors for SSIs in mastectomy patients. Methods By using the American College of Surgeons' National Surgical Quality Improvement Program database, all patients undergoing mastectomy from 2005 to 2009 were identified. The outcome was to determine the incidence rate and identify significant independent risk factors of SSIs. Results The incidence of SSI was 2.3% (891 of 38,739; 95% confidence interval, 2.2%–2.5%) in patients undergoing mastectomy without reconstruction. Significant ( P < .05) risk factors for SSI included a body mass index greater than 25, American Society of Anesthesiology classification of 3 or higher, diabetes mellitus, surgical time of 2 hours or longer (75th percentile), and current smoking status. Conclusions Before this study, there was wide variation in the incidence rate of surgical site infections in this patient population. This was a large-scale study to address these inconsistencies.
Surgical site infections (SSI) are a source of significant postoperative morbidity and cost. Although immediate breast reconstruction after mastectomy has become routine, the data regarding the ...incidence of SSI in immediate breast reconstruction is highly variable and series dependent.
Using the National Surgical Quality Improvement Program database, all female patients undergoing mastectomy, with or without immediate reconstruction, from 2005 to 2009 were identified. Only "clean" procedures were included. The primary outcome was incidence of SSI within 30 days of operation. Stepwise logistic regression analysis was used to identify risk factors associated with SSI.
A total of 48,393 mastectomies were performed during the study period, of which 9315 (19.2%) had immediate breast reconstruction. The incidence of SSI was 3.5% (330/9315) (95% CI confidence interval: 3.2%-4%) in patients undergoing mastectomy with reconstruction and 2.5% (966/39,078) (95% CI: 2.3%-2.6%) in patients undergoing mastectomy without reconstruction (P < 0.001). Independent risk factors for SSI include increased preoperative body mass index (BMI), heavy alcohol use, ASA (American Society of Anesthesiologists) score greater than 2, flap failure, and operative time of 6 hours or longer.
Immediate breast reconstruction is associated with a statistically significant increase in risk of SSI in patients undergoing mastectomy (3.5% vs 2.5%). However, this difference was not considered to be clinically significant. In this large series, increased BMI, alcohol use, ASA class greater than 2, flap failure, and prolonged operative time were associated with increased risk of SSI.
The X-band electron paramagnetic resonance spectroscopy (EPR) of a stable, spherical nitroxide spin probe, perdeuterated 2,2,6,6-tetramethyl-4-oxopiperidine-1-oxyl (pDTO) has been used to study the ...nanostructural organization of a series of 1-alkyl-3-methylimidazolium tetrafluoroborate ionic liquids (ILs) with alkyl chain lengths from two to eight carbons. By employing nonlinear least-squares fitting of the EPR spectra, we have obtained values of the rotational correlation time and hyperfine coupling splitting of pDTO to high precision. The rotational correlation time of pDTO in ILs and squalane, a viscous alkane, can be fit very well to a power law functionality with a singular temperature, which often describes a number of physical quantities measured in supercooled liquids. The viscosity of the ILs and squalane, taken from the literature, can also be fit to the same power law expression, which means that the rotational correlation times and the ionic liquid viscosities have similar functional dependence on temperature. The apparent activation energy of both the rotational correlation time of pDTO and the viscous flow of ILs and squalane increases with decreasing temperature; in other words, they exhibit strong non-Arrhenius behavior. The rotational correlation time of pDTO as a function of η/T, where η is the shear viscosity and T is the temperature, is well described by the Stokes–Einstein–Debye (SED) law, while the hydrodynamic probe radii are solvent dependent and are smaller than the geometric radius of the probe. The temperature dependence of hyperfine coupling splitting is the same in all four ionic liquids. The value of the hyperfine coupling splitting starts decreasing with increasing alkyl chain length in the ionic liquids in which the number of carbons in the alkyl chain is greater than four. This decrease together with the decrease in the hydrodynamic radius of the probe indicates a possible existence of nonpolar nanodomains.
The work in part 6 of this series (J. Phys. Chem. A 2009, 113, 4930), addressing the task of separating the effects of Heisenberg spin exchange (HSE) and dipole–dipole interactions (DD) on electron ...paramagnetic resonance (EPR) spectra of nitroxide spin probes in solution, is extended experimentally and theoretically. Comprehensive measurements of perdeuterated 2,2,6,6-tetramethyl-4-oxopiperidine-1-oxyl (pDT) in squalane, a viscous alkane, paying special attention to lower temperatures and lower concentrations, were carried out in an attempt to focus on DD, the lesser understood of the two interactions. Theoretically, the analysis has been extended to include the recent comprehensive treatment by Salikhov (Appl. Magn. Reson. 2010, 38, 237). In dilute solutions, both interactions (1) introduce a dispersion component, (2) broaden the lines, and (3) shift the lines. DD introduces a dispersion component proportional to the concentration and of opposite sign to that of HSE. Equations relating the EPR spectral parameters to the rate constants due to HSE and DD have been derived. By employing nonlinear least-squares fitting of theoretical spectra to a simple analytical function and the proposed equations, the contributions of the two interactions to items 1–3 may be quantified and compared with the same parameters obtained by fitting experimental spectra. This comparison supports the theory in its broad predictions; however, at low temperatures, the DD contribution to the experimental dispersion amplitude does not increase linearly with concentration. We are unable to deduce whether this discrepancy is due to inadequate analysis of the experimental data or an incomplete theory. A new key aspect of the more comprehensive theory is that there is enough information in the experimental spectra to find items 1–3 due to both interactions; however, in principle, appeal must be made to a model of molecular diffusion to separate the two. The permanent diffusion model is used to illustrate the separation in this work. In practice, because the effects of DD are dominated by HSE, negligible error is incurred by using the model-independent extreme DD limit of the spectral density functions, which means that DD and HSE may be separated without appealing to a particular model.
Chronic wounds in previously radiated tissue are challenging to treat. In this article, the authors describe 3 such wounds that failed to heal despite multiple treatments with traditional wound ...healing methods. Treatment with porcine urinary bladder matrix, an extracellular matrix material, was initiated to facilitate epithelialization and promote wound healing. MatriStem powder (ACell, Inc, Columbia, Maryland), MatriStem (ACell, Inc) sheet, and DuoDerm (ConvaTec, Skillman, New Jersey) were applied biweekly and resulted in complete wound closure within 3 weeks of initial application for all 3 cases. All wounds remained closed 9 months following treatment, suggesting a role for urinary bladder matrix in the management of chronic wounds in the setting of irradiated tissue.
There are numerous factors that may contribute to microvascular free flap failure. Although technical issues are dominant factors, patient and clinical characteristics are also contributory. The aim ...of this study was to investigate non-technical variables associated with microsurgical free flap failure using a multi-institutional dataset.
Utilizing the American College of Surgeons' National Surgical Quality Improvement Program (NSQIP) database, we identified all patients who underwent microvascular free tissue transfer from 2005 through 2009. Univariate analysis was performed to determine the association of flap failure with the following factors: age, gender, ethnicity, body mass index, intraoperative transfusion, diabetes, smoking, alcohol, American Society of Anesthesiologists classification, year of operation, operative time, number of flaps, and type of reconstruction. Factors with a significance of P < 0.2 in the univariate analysis were included in the multivariate logistic regression model to identify independent risk factors.
A total of 639 patients underwent microsurgical free flap reconstruction with 778 flaps over the 4-year study period; 139 patients had two free flaps during the same operation. The overall incidence of flap failure was 4.4% (34/778) (95% confidence interval CI: 3.0%, 6.2%). Operative time was identified as an independent risk factor for free flap failure. After adjusting for other factors, those whose operative time was equal to or greater than the 75th percentile (625.5 min) were twice as likely to experience flap failure (AOR 2.09; 95% CI: 1.01-4.31; P = 0.045). None of the other risk factors studied were significant contributors.
In this series, the overall flap loss rate of was 4.4%. Operative time was a significant independent risk factor for flap failure.
The work in Part 6 of this series (
J. Phys. Chem. A
2009,
113
, 4930), addressing the task of separating the effects of Heisenberg spin exchange (HSE) and dipole-dipole (DD) interactions on EPR ...spectra of nitroxide spin probes in solution, is extended experimentally and theoretically. Comprehensive measurements of perdeuterated 2,2,6,6-tetramethyl-4-oxopiperidine-1-oxyl (pDT) in squalane, a viscous alkane, paying special attention to lower temperatures and lower concentrations were carried out in an attempt to focus on DD, the lesser understood of the two interactions. Theoretically, the analysis has been extended to include the recent comprehensive treatment by Salikhov (
Appl. Magn. Reson.
2010,
38
, 237). In dilute solutions, both interactions (1) introduce a dispersion component, (2) broaden the lines, and (3) shift the lines. DD introduces a dispersion component proportional to the concentration and of opposite sign to that of HSE. Equations relating the EPR spectral parameters to the rate constants due HSE and DD have been derived. By employing non-linear least-squares fitting of theoretical spectra to a simple analytical function and the proposed equations, the contributions of the two interactions to items (1)–(3) may be quantified and compared with the same parameters obtained by fitting experimental spectra. This comparison supports the theory in its broad predictions, however, at low temperatures, the DD contribution to the experimental dispersion amplitude does not increase linearly with concentration. We are unable to deduce if this discrepancy is due to inadequate analysis of the experimental data or an incomplete theory. A key new aspect of the more comprehensive theory is that there is enough information in the experimental spectra to find items (1)–(3) due to both interactions; however, in principle, appeal must be made to a model of molecular diffusion to separate the two. The permanent diffusion model is used to illustrate the separation in this work. In practice, because the effects of DD are dominated by HSE, negligible error is incurred by using the model-independent extreme DD limit of the spectral density functions which means that DD and HSE may be separated without appealing to a particular model.
The absence of the palmaris longus (PL) has been shown to vary based on body side, gender, and ethnicity. In prior studies, homogenous ethnic populations have been shown to have differences in rates ...of absence. However, no study thus far has analyzed the differences in palmaris longus prevalence in a multiethnic population. We prospectively collected data on 516 patients visiting the outpatient hand clinics at LAC+USC Medical Center and Keck Medical Center. Analysis of the data was then performed for variables including ethnicity, laterality, and gender. There were no differences in the absence of the PL based on laterality or gender. Ethnically, there was no difference between white (non-Hispanic) and white (Hispanic) patients, with prevalence of 14.9% and 13.1%, respectively. However, African American (4.5%) and Asian (2.9%) patients had significantly fewer absences of the PL than the Caucasian, Hispanic reference group (P=0.005 and P=0.008, resp.). African Americans and Asians have a decreased prevalence of an absent PL. The Caucasian population has a relatively greater prevalence of an absence of the PL. This epidemiological study demonstrates the anatomic variation in this tendon and may be taken into account when planning an operation using tendon grafts.
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