Nova School of Business and Economics
Recent publications
Aims Research on hip biomechanics has analyzed femoroacetabular contact pressures and forces in distinct hip conditions, with different procedures, and used diverse loading and testing conditions. The aim of this scoping review was to identify and summarize the available evidence in the literature for hip contact pressures and force in cadaver and in vivo studies, and how joint loading, labral status, and femoral and acetabular morphology can affect these biomechanical parameters. Methods We used the PRISMA extension for scoping reviews for this literature search in three databases. After screening, 16 studies were included for the final analysis. Results The studies assessed different hip conditions like labrum status, the biomechanical effect of the cam, femoral version, acetabular coverage, and the effect of rim trimming. The testing and loading conditions were also quite diverse, and this disparity limits direct comparisons between the different researches. With normal anatomy the mean contact pressures ranged from 1.54 to 4.4 MPa, and the average peak contact pressures ranged from 2 to 9.3 MPa. Labral tear or resection showed an increase in contact pressures that diminished after repair or reconstruction of the labrum. Complete cam resection also decreased the contact pressure, and acetabular rim resection of 6 mm increased the contact pressure at the acetabular base. Conclusion To date there is no standardized methodology to access hip contact biomechanics in hip arthroscopy, or with the preservation of the periarticular soft-tissues. A tendency towards improved biomechanics (lower contact pressures) was seen with labral repair and reconstruction techniques as well as with cam correction. Cite this article: Bone Joint Res 2023;12(12):712–721.
Portugal introduced a sugar-sweetened beverages (SSB) tax in 2017. This study uses unique administrative accounting data for all SSB producers/importers in Portugal, and an event study design with bottled water firms as the primary comparison group, to assess the causal impacts of the tax on multiple firm-level outcomes. We find a 6.8% average decrease in domestic SSB sales, relative to bottled water. The soda tax hindered SSB firms’ financial health, namely net income, ability to convert receivables into cash, and liabilities. SSB producers/importers did not decrease wages, cut jobs, or modify their workforce toward higher R&D capacity. Forgone corporate income tax appears negligible compared to the government revenue generated by the tax itself.
Ceftazidime/avibactam-resistance in Klebsiella pneumoniae carbapenemase-producing Klebsiella pneumoniae (KPC-Kp) is a topic of great interest for epidemiological, diagnostic, and therapeutical reasons. However, data on its prevalence and burden on mortality in patients with bloodstream infection (BSI) are lacking. This study was aimed at identifying risk factors for mortality in patients suffering from ceftazidime/avibactam-resistant KPC-Kp BSI. An observational retrospective study (January 2018–December 2022) was conducted at a tertiary hospital including all consecutive hospitalized adult patients with a ceftazidime/avibactam-resistant KPC-Kp BSI. Data on baseline clinical features, management, and admission outcomes were analyzed. Over the study period, among all the KPC-Kp BSI events recorded, 38 (10.5%) were caused by ceftazidime/avibactam-resistant KPC-Kp strains, 37 events being finally included. The ceftazidime/avibactam-resistant KPC-Kp strains revealed susceptibility restoration to at least one carbapenem in more than 60% of cases. In-hospital and 30-day all-cause mortality rates were 22% and 16.2%, respectively. Non-survivors suffered from more baseline comorbidities and experienced a more severe ceftazidime/avibactam-resistant KPC-Kp BSI presentation (i.e., both the Pitt Bacteremia and INCREMENT-CPE scores were significantly higher). Presenting with a higher Charlson Comorbidity Index, chronic kidney disease—KDIGO stage 3A or worse—having recently gone through renal replacement therapy, having suffered from an acute kidney injury following the ceftazidime/avibactam-resistant KPC-Kp BSI, and being admitted for cardiac surgery were the strongest predictors of mortality. Ceftazidime/avibactam resistance in KPC-Kp BSI easily emerged in our highly KPC-Kp endemic area with remarkable mortality rates. Our findings might provide physicians possibly actionable information when managing patients with a ceftazidime/avibactam-resistant KPC-Kp BSI.
Purpose Recent studies suggested a protective role of metformin in the development of colorectal cancer (CRC) and its precursors. We aimed to investigate if metformin was associated with a lower prevalence and number of colorectal polyps in diabetic patients and also adenomas, high-risk adenomas, and CRC. Methods Retrospective study on adult patients with diabetes mellitus followed in our hospital with a total colonoscopy between 2015 and 2019, treated with either metformin for > 5 years or other antidiabetic agent (control group). We assessed the number, size, and histopathology examination of proliferative lesions detected on colonoscopy. Results We included 401 patients aged 69 ± 9 years, 57% males, divided into two groups: treated with metformin (n = 260) and without (n = 141). The number of polyps detected was significantly lower in patients under metformin (p = 0.014). There was a nonsignificant trend towards lower polyp detection rates in the metformin compared to the control group both in unadjusted analysis (50% vs 60%, p = 0.058) and multivariable adjusted analysis (odds ratio [OR] 0.68, 95% confidence interval [CI] 0.43–1.09, p = 0.111). In the latter, we identified male gender (OR 2.24, 95%CI 1.44–3.49, p < 0.001), age (OR 1.35 for every 10 years, 95%CI 1.07–1.71, p = 0.012), glycated hemoglobin value (OR 1.20 for every 1% increase, 95%CI 1.06–1.37, p = 0.005), and hypertension (OR 1.76, 95%CI 1.01–3.08, p = 0.046) as factors associated with a higher prevalence of polyps. We saw no statistically significant differences regarding adenoma (p = 0.231), high-risk adenoma (p = 0.810), and CRC (p = 0.705) diagnoses between groups. Conclusion In our study, metformin was associated with less colorectal polyps in diabetic patients compared to other treatment modalities. We observed a nonsignificant trend towards lower polyp detection rates in the metformin group both in unadjusted and adjusted analyses.
The aim of this study was to assess the biomechanical effects of subtalar ligament injury and reconstruction on stability of the subtalar joint in all three spatial planes. Fifteen fresh frozen cadaveric legs were used, with transfixed tibiotalar joints to isolate motion to the subtalar joint. An arthrometer fixed to the lateral aspect of the calcaneus measured angular displacement in all three spatial planes on the inversion and eversion stress tests. Stress manoeuvres were tested with the intact joint, and then repeated after sequentially sectioning the inferior extensor retinaculum (IER), cervical ligament (CL), interosseous talocalcaneal ligament (ITCL), arthroscopic graft reconstruction of the ITCL, and sectioning of the calcaneo-fibular ligament (CFL). Sectioning the ITCL significantly increased angular displacement upon inversion and eversion in the coronal and sagittal planes. Reconstruction of the ITCL significantly improved angular stability against eversion in the axial and sagittal planes, and against inversion in the axial and coronal planes, at the zero time point after reconstruction. After sectioning the CFL, resistance to eversion decreased significantly in all three planes. Progressive injury of ligamentous stabilisers, particularly the ITCL, led to increasing angular displacement of the subtalar joint measured with the inversion and eversion stress tests, used in clinical practice. Reconstruction of the ITCL using tendon graft significantly stabilised the subtalar joint in the axial and sagittal planes against eversion and in the axial and coronal planes against inversion, immediately after surgery.
Introduction Calibrated integrated backscatter (cIB) may be obtained from bidimensional (2D) strain echocardiography as a quantification measurement of myocardial ultrasound reflectivity. Increased collagen content of the myocardium modifies tissue reflectivity and cIB is suggested as a marker of left ventricular (LV) fibrosis. However, its diagnostic accuracy is not fully established. Aim To assess the correlation between cIB by 2D strain and LV myocardial fibrosis (MF), as evaluated by non-invasive imaging and histopathology. Methods Correlation study from a cohort of 157 patients with severe symptomatic aortic stenosis (AS) referred for surgical aortic valve replacement (AVR). Patients with complete preoperative transthoracic echocardiography, cardiac magnetic resonance (CMR) and endomyocardial biopsy (EMB) obtained from the anterior basal septum at the time of AVR were selected. Two groups of 30 patients were evaluated, with and without late gadolinium enhancement (LGE) at CMR. Integrated Backscatter was obtained at QRS peak in decibels (dB) from both parasternal long axis (PLAX) and apical-three-chamber (A3C) cine clips at Qanalysis. cIB was calculated by subtracting the pericardial intensity from the average of the anteroseptal and basal inferolateral wall values. Correlation analysis was performed for the whole group of patients with global and segmental (anterior basal septum) values of native T1 and extracellular volume (ECV), and EMB collagen volume fraction (CVF) from Masson´s Trichrome staining. IBS values were compared in both group of patients. Results 60 patients (74 [36-74] years, 45% male) with high gradient (mean gradient: 63±20mmHg), normal flow (45±10mL/m2), preserved ejection fraction (60±9%) AS were included. Basal septal cIB was –9.17±9.45dB and –17.45 (–31.2–10.95) dB from A3C and PLAX views, respectively. These indexes did not correlate with basal septum thickness or global LV mass. Absolute and cIB did not correlate neither with global and regional T1 and ECV values, nor with CVF at EMB. These were not significantly different in both groups of patients and there was no correlation between cIB values and mass of replacement MF in patients with LGE. Conclusion In these cohort of patients with classical severe AS, there was no correlation of cIB with imaging markers of both replacement and diffuse MF. cIB also didn´t correlate with CVF at histopathology. These findings suggest that reflectivity indexes are not suitable for myocardial tissue characterization in this setting.
Introduction The persistence of antiphospholipid antibodies (aPL) is associated with a procoagulant state that could precipitate thrombotic events in the presence of a second pro-inflammatory stimulus, realizing thus the antiphosholipid syndrome (APS). Circulating lipopolysaccharide (LPS) is associated with systemic inflammation, enhanced oxidative stress and cardiovascular events in different clinical conditions, however, its presence and significance has not been evaluated in APS. Purpose To investigate the relationship between LPS, oxidative stress markers and risk of thrombotic events in the prospective multicenter ATHERO-APS study. Methods Baseline serum levels comparison of LPS, soluble NADPH oxidase 2-derived peptide (sNOX-dp), H2O2 production, hydrogen peroxide breakdown activity (HBA), and nitric oxide (NO) bioavailability in 97 primary APS (PAPS), 20 aPL carriers and 20 healthy controls (CTRL) matched for age, sex and BMI. In patients with high LPS levels, Cox-regression analysis was performed to assess the risk for a composite outcome of cardiovascular death, venous (VTE) and arterial thromboembolism (ATE). Results In the whole population (median age 51 (IQR: 45-61) years, 72% female), LPS levels were inversely correlated with HBA (Rs: -0.231, p=0.009) and NO (rS: -0.286, p=0.001) and directly correlated with sNOX-dp (rS:0.423, p<0.001) and H202 (rS: 0.211, p=0.017) (Table 1). Patients with PAPS showed a significant increased levels of LPS, sNOX-dp and H2O2 and a significant lower level of NO and HBA compared to aPL carriers and healthy CTRL. No correlation was found between LPS levels and anti-cardiolipin (aCL) IgG/IgM, anti-beta-2-Glycoprotein-I (aβ2GPI) IgG/IgM and lupus anticoagulant (LAC). After a median follow-up of 4.7 (4.1-5.6) years, 11 composite outcomes were reported: 1 cardiovascular death (stroke related), 3 ischemic strokes, 2 myocardial infarctions, 3 peripheral ATE and 2 VTE. Patients with basal LPS levels above the median value (>20.1 pg/ml) showed a higher annual incidence of composite outcome compared to those with LPS levels below the median value (4.0% vs 0.7%, p=0.013). On Cox-regression analysis, PAPS patients with LPS above the median value showed a 5-fold increased risk of composite outcome compared to patients with LPS below the median value, after adjustment for age, sex, aCL IgG, aβ2GPI IgG and LAC (Figure 1). Conclusion These preliminary data suggest that in PAPS, LPS is associated with a higher risk for a composite outcome of cardiovascular death, ATE and VTE. Further studies are needed to know which pharmacological approach may counteract the prothrombotic effect of LPS.
Objectives To determine the role of diffusion-weighted imaging (DWI) for predicting response to neoadjuvant therapy (NAT) in pancreatic cancer. Materials and methods MEDLINE, EMBASE, and Cochrane Library databases were searched for studies evaluating the performance of apparent diffusion coefficient (ADC) to assess response to NAT. Data extracted included ADC pre- and post-NAT, for predicting response as defined by imaging, histopathology, or clinical reference standards. ADC values were compared with standardized mean differences. Risk of bias was assessed using the Quality Assessment of Diagnostic Studies (QUADAS-2). Results Of 337 studies, 7 were included in the analysis (161 patients). ADC values reported for the pre- and post-NAT assessments overlapped between responders and non-responders. One study reported inability of ADC increase after NAT for distinguishing responders and non-responders. A correlation with histopathological response was reported for pre- and post-NAT ADC in 4 studies. DWI’s diagnostic performance was reported to be high in three studies, with a 91.6–100% sensitivity and 62.5–94.7% specificity. Finally, heterogeneity and high risk of bias were identified across studies, affecting the domains of patient selection, index test, reference standard, and flow and timing. Conclusion DWI might be useful for determining response to NAT in pancreatic cancer. However, there are still too few studies on this matter, which are also heterogeneous and at high risk for bias. Further studies with standardized procedures for data acquisition and accurate reference standards are needed. Clinical relevance statement Diffusion-weighted MRI might be useful for assessing response to neoadjuvant therapy in pancreatic cancer. However, further studies with robust data are needed to provide specific recommendations for clinical practice. Key Points •The role of DWI with ADC measurements for assessing response to neoadjuvant therapy in pancreatic cancer is still unclear. •Pre- and post-neoadjuvant therapy ADC values overlap between responders and non-responders. •DWI has a reported high diagnostic performance for determining response when using histopathological or clinical reference standards; however, studies are still few and at high risk for bias.
Background Non-adherence to medical guidelines is associated with suboptimal health outcomes and increased healthcare costs, and yet adherence to preventive therapies is often difficult to achieve. Understanding which factors can improve adherence is a public health priority. In this study, we examined the association of psychosocial factors and adherence of preventive behaviors within the context of the COVID-19 pandemic. Methods Panel data from the European COvid Survey (ECOS), a representative sample of residents aged 18+ from Germany, United Kingdom, Denmark, Netherlands, France, Portugal and Italy collected from April 2020 (wave 1) to May 2022 (wave 10) was used to examine trends and determinants of COVID-19 preventive behaviors (i.e., mask wearing, hand washing). Results With a total of 27,095 participants, 53.5% were female, and 15.9% were aged 18-24, 67.9% 25-64, and 16.3% 65+. The trends in adherence decreased over time except in wave 5 where a spike in adherence levels matched wave 1 levels and a surge in reported COVID-19 infections. In multivariable logistic regression models, worry about overloading the health system (OR = 1.26, 95%CI: 1.22-1.31), perceived risk to one's own health (OR = 1.13, 95%CI: 1.08-1.18) and others (OR = 1.16, 95%CI: 1.10-1.22), and trust in institutions (OR = 1.20, 95%CI: 1.12-1.26), traditional news media (OR = 1.05, 95%CI: 1.01-1.10), and health providers (OR = 1.31, 95%CI: 1.26-1.37) increased the likelihood of engaging in COVID-19 preventive behaviors. However, those with high trust in social media were less likely to follow prevention guidelines (OR = 0.78, 95%CI: 0.75-0.80). Conclusions Psychosocial factors (risk perceptions, worry, and trust variables) were associated with adhering to COVID-19 prevention guidelines. Findings that high trust in social media was related to low adherence suggests more research is needed to understand how public health can improve health communications via social media, a popular information resource. Key messages • Health risk perceptions and worry about overloading the health system were associated with adhering to COVID-19 prevention guidelines. • Trust in social media was related to low adherence to COVID-19 prevention guidelines.
Many platforms host user-generated content (UGC) and content developed by professionals side by side. However, thus far, their impact on platform ecosystems has been mostly studied in isolation. In this paper, we use data from a network of 122 local news outlets hosted by an online news platform to study the spillover effects from UGC developed by citizen journalists to the content developed by professional journalists. We use the removal of a status index associated with citizen journalists as an exogenous shock to their supply of UGC to identify these spillover effects. We find that experienced citizen journalists reduce their production of content when this status index is removed. We then find that inexperienced professional journalists increase their output in response to this behavior. However, as a result of these changes, we find a reduction in the overall content hosted by the platform, especially in the case of local news and in more isolated regions. We further show that this is likely to have detrimental effects for the platform. In particular, there is a decline in overall viewership, and the platform may need to hire and pay salaries to more professional journalists to produce enough articles to close the gap left by the departing citizen journalists. Our work contributes to the literature on UGC and online platforms and to the literature on local news. This paper was accepted by D. J. Wu, information systems division. Supplemental Material: The online appendix and data files are available at .
Regardless of the benefits of fall prevention programs, people with Parkinson’s disease (PD) will still fall. Therefore, it is crucial to explore novel therapeutic approaches that are well-accepted and effective for addressing fall risk and the fear of falls among this population. The present study aims to assess the feasibility of the Landing Wise program as a therapeutic intervention for reducing the fear of falling in people with PD. A mixed-methods study will be conducted using convenience sampling to recruit 20 people with PD with a moderate concern of falling from a Parkinson’s Patients Association. In addition to usual care, participants will attend 2 days per week, 90 min group sessions for 8 weeks. The intervention combines group cognitive behavioral intervention with the training of safe landing strategies. Feasibility will be assessed by six key domains (recruitment strategy and rates, enrollment, retention, acceptability, reasons for decline/withdrawal, and adverse events). Quantitative data will be analyzed using descriptive statistics to characterize the sample, followed by inferential statistics to evaluate differences in the Short Falls Efficacy Scale-International Scale, Movement Disorder Society Unified Parkinson’s Disease Rating Scale, Timed Up Go, 6-Minutes Walking Distance, and fall frequency and severity scores between baseline and final assessment. Qualitative data will be analyzed using an inductive thematic analysis process. There is a growing interest in developing new effective therapeutic approaches for people with PD. If proven program feasibility, this study precedes a randomized controlled trial to establish the effectiveness of the Landing Wise program.
Background: Exercise testing is key in the risk stratification of patients with heart failure (HF). There are scarce data on its prognostic power in women. Our aim was to assess the predictive value of the heart transplantation (HTx) thresholds in HF in women and in men. Methods: Prospective evaluation of HF patients who underwent cardiopulmonary exercise testing (CPET) from 2009 to 2018 for the composite endpoint of cardiovascular mortality and urgent HTx. Results: A total of 458 patients underwent CPET, with a composite endpoint frequency of 10.5% in females vs. 16.0% in males in 36-month follow-up. Peak VO2 (pVO2), VE/VCO2 slope and percent of predicted pVO2 were independent discriminators of the composite endpoint, particularly in women. The International Society for Heart Lung Transplantation recommended values of pVO2 ≤ 12 mL/kg/min or ≤14 if the patient is intolerant to β-blockers, VE/VCO2 slope > 35, and percent of predicted pVO2 ≤ 50% showed a higher diagnostic effectiveness in women. Specific pVO2, VE/VCO2 slope and percent of predicted pVO2 cut-offs in each sex group presented a higher prognostic power than the recommended thresholds. Conclusion: Individualized sex-specific thresholds may improve patient selection for HTx. More evidence is needed to address sex differences in HF risk stratification.
Liquid-based cytology (LBC) is a method of retrieving and processing cytologic material for assessment. First developed for cervical cytology screening in an effort to reduce inadequacy rates, the use of LBC has extended to FNAC as well. In LBC, cytologic material is placed in a fixative solution and, depending on the system, is then centrifuged or filtered to produce monolayers of cells on glass slides and this can enhance and facilitate interpretation. These monolayered preparations can also be subjected to adjunctive studies like immunohistochemistry. There are many ways of achieving monolayered cell preparations, which may be through automated platforms like ThinPrep and SurePath, or via alternative manual techniques that are less costly and that can produce similar monolayered preparations. Overall, the literature reports overlapping sensitivities and specificities between conventional smears and liquid-based cytology slides in the context of breast FNAC. Notably, however, one study found that monolayered preparations of breast aspirates gave definitive diagnoses significantly more often than aspirates subjected to conventional smear preparations (72.8% vs. 58.5%) and that this benefit was most frequently observed in malignant breast lesions.
Fine needle aspiration cytology (FNAC) is a minimally invasive, cost-effective technique with high diagnostic accuracy. In an era where medical care often relies on expensive and complex technology, FNAC runs opposite to this trend. It is a safe procedure, allows for rapid reporting and diagnosis, and demonstrates high sensitivity and specificity for the diagnosis of malignancy. In addition, this technique requires little equipment, causes minimal discomfort to the patients, can easily be performed as an outpatient procedure, and reduces bed occupancy and the incidence of additional surgical explorations. An aspiration can be performed during a routine doctor’s office or clinic visit or at the patient’s bedside. It requires practice and skill, however, both in the performance of the aspiration itself and in the interpretation of the results. The recently released Yokohama System for Reporting Breast Fine Needle Aspiration Biopsy Cytopathology is a useful guide for practitioners without experience and interested in taking advantage. Implementation should take place slowly but surely. FNAC is a multistep procedure, and when all steps are done by a single person, the pathologist, final results are usually better. Correctly executed, FNAC has the best safety record of any method of obtaining material for a morphological diagnosis. It also allows for collecting material for ancillary testing, such as immunohistochemistry.
The application of molecular techniques has changed the practice of cytopathology. Currently, the use of ancillary molecular techniques on cytology samples is widely accepted as an adjuvant of morphology for both diagnostic and prognostic purposes. Cytological samples are easier to obtain than tissue biopsies and allow for the evaluation of sample adequacy at the time of the procedure, making them ideal for molecular studies. In the context of breast cancer, these samples are usually obtained either by effusion draining or fine needle aspiration biopsies (FNAB), which are minimally invasive procedures with minimal to no complications, enabling repeated testing over the course of the disease. This allows for the monitoring of emerging clones resistant to targeted therapy, for example, increasingly important in the age of personalized medicine. Furthermore, sample preservation is often better than formalin-fixed, paraffin-embedded tissue, particulary when liquid fixatives are used.
With the growing complexity of social and environmental issues, there has been a blossoming of hackathons and open innovation challenges. This push to accelerate innovation embraces a perspective of time as clock time—conceived as objective, linear, measurable, and therefore, rather easy to compress. Such a view of time conflicts with the emergent nature of idea generation and the indeterminate process that leads to social impact, which both rely on event time. Drawing on a 40-month ethnographic study of OpenIDEO, an open social innovation platform, I examine how, in designing open innovation challenges, the OpenIDEO team interwove clock time and event time in order to foster idea generation and support social impact. Through inductive analysis, I identify three practices—mapping, stretching, and squeezing time—enacted by the OpenIDEO team to “make time” and thus, continuously engage participants and sponsors in the challenges as well as to allow participants to implement their ideas. My findings demonstrate how organizations can intentionally use time to nurture collaborative innovation and yield sustainable social impact. My study questions the traditional interpretation of clock time as the foundation of all temporalities as it shows how temporal work can be grounded within event time. Funding: This work was supported by the National Science Foundation [NSF VOSS Grant 1122381].
As workers and family members, individuals ought to celebrate seemingly positive events (e.g., a promotion and the purchase of a home). Yet, the numerous identities that contemporary workers hold increase the likelihood of an event that is pleasant in one domain being problematic in another and more cognitively and affectively complex than anticipated. We theorize that these events are likely to prompt self‐evaluations that are positive (“I'm a success!”) and negative (“I'm a failure.”) across one's identity set, with questions such as “Who have I become?” and “Is this who I ought to be?” The result is self‐ambivalence, that is, a simultaneously oppositional orientation toward oneself. We view this as a contemporary cognitive and affective experience for which theorizing in work and family is largely absent. Our conceptual model begins with “work–family ought events,” events accompanied by both possibilities and limitations that prompt identity‐related self‐examination. We acknowledge the influence of multi‐level social systems including organizational, societal, individual, and partner factors, which can intensify self‐ambivalence. We propose the experience of self‐ambivalence has implications for self‐concept clarity and ultimately well‐being in both the work and family domains and extend theory on this problem of self‐ambivalence, a problem that heretofore “had no name.”
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775 members
Luis F. Martinez
  • Department of Business Management
Miguel Ferreira
  • Department of Finance
Luis Filipe Lages
  • Universidade Nova de Lisboa
Lisbon, Portugal