Efficiency and Productivity Change of Public Hospitals in Panama: Do Management Schemes Matter?

In Latin American and Caribbean countries, the main concern of public health care managers has been traditionally placed on problems related to funding, payment mechanisms, and equity of access. However, more recently, there is a growing interest in improving the levels of efficiency and reducing costs in the provision of health services. In this paper we focus on measuring the technical efficiency and productivity change of public hospitals in Panama using bootstrapped Malmquist indices, which allows us to assess the statistical significance of changes in productivity, efficiency, and technology. Specifically, we are interested in comparing the performance of hospitals belonging to the two different management schemes coexisting in the country, the Social Security Fund (SSF) and the Ministry of Health (MoH). Our dataset includes data about 22 public hospitals (11 for each model) during the period between 2005 and 2015. The results showed that the productivity growth of hospitals belonging to the SSF has been much higher than that of the hospitals belonging to the Ministry of Health over the evaluated period (almost 4% compared to 1.5%, respectively). The main explanation for these divergences is the superior growth of technological change in the former hospitals, especially in the final years of the evaluated period.

A Ligand System for the Flexible Functionalization of Quantum Dots via Click Chemistry.

We present a novel ligand, 5-norbornene-2-nonanoic acid, which can be directly added during established quantum dot (QD) syntheses in organic solvents to generate "clickable" QDs at a few hundred nmol scale. This ligand has a carboxyl group at one terminus to bind to the surface of QDs and a norbornene group at the opposite end that enables straightforward phase transfer of QDs into aqueous solutions via efficient norbornene/tetrazine click chemistry. Our ligand system removes the traditional ligand-exchange step and can produce water-soluble QDs with a high quantum yield and a small hydrodynamic diameter of approximately 12 nm at an order of magnitude higher scale than previous methods. We demonstrate the effectiveness of our approach by incubating azido-functionalized CdSe/CdS QDs with 4T1 cancer cells that are metabolically labeled with a dibenzocyclooctyne-bearing unnatural sugar. The QDs exhibit high targeting efficiency and minimal nonspecific binding.

Near-Infrared Quantum Dot Emission Enhanced by Stabilized Self-Assembled J-Aggregate Antennas.

Enhancing photoluminescent emission (PL) in the near-infrared-infrared (NIR-IR) spectral region has broad applications from solar energy conversion to biological imaging. We show that self-assembled molecular dye J-aggregates (light-harvesting nanotubes, LHNs) can increase the PL emission of NIR PbS quantum dots (QDs) in both liquid and solid media more than 8-fold, promoted primarily by a long-range antenna effect and efficient Förster resonance energy transfer (FRET) from donor to acceptor. To create this composite material and preserve the optical properties of the nanocrystals, we performed an in situ ligand substitution followed by a functionalization reaction using click-chemistry. This resulted in PbS QDs soluble in an aqueous environment compatible with the molecular J-aggregates (LHNs). Theoretical and experimental results demonstrate that long-range diffusive exciton transport in LHNs enables efficient energy transfer to low concentrations of QDs despite there being no direct binding between molecular donors and QD acceptors. This suggests a broad application space for mixed light harvesting and photophysically active nanocomposite materials based on self-assembling molecular aggregates.

Shortwave Infrared in Vivo Imaging with Gold Nanoclusters.

The use of visible/NIR-emitting gold nanoclusters (Au NCs), previously proposed for in vivo imaging, has been limited to some extent by low quantum yields (QYs) and the limited penetration of visible light in tissue. Here we report short wavelength infrared (SWIR, λ = 1-2 µm) emitting Au NCs with a good photoluminescence QY for this wavelength range (0.6% to 3.8% for λem = 1000 to 900 nm) and excellent stability under physiological conditions. We show that surface ligand chemistry is critical to achieving these properties. We demonstrate the potential of these SWIR-emitting Au NCs for in vivo imaging in mice. The Au NCs have a hydrodynamic diameter that is small (∼5 nm) enough that they exhibit a rapid renal clearance, and images taken in the SWIR region show better resolution of the blood vessels than in the NIR region.

Exceedingly small iron oxide nanoparticles as positive MRI contrast agents.

Medical imaging is routine in the diagnosis and staging of a wide range of medical conditions. In particular, magnetic resonance imaging (MRI) is critical for visualizing soft tissue and organs, with over 60 million MRI procedures performed each year worldwide. About one-third of these procedures are contrast-enhanced MRI, and gadolinium-based contrast agents (GBCAs) are the mainstream MRI contrast agents used in the clinic. GBCAs have shown efficacy and are safe to use with most patients; however, some GBCAs have a small risk of adverse effects, including nephrogenic systemic fibrosis (NSF), the untreatable condition recently linked to gadolinium (Gd) exposure during MRI with contrast. In addition, Gd deposition in the human brain has been reported following contrast, and this is now under investigation by the US Food and Drug Administration (FDA). To address a perceived need for a Gd-free contrast agent with pharmacokinetic and imaging properties comparable to GBCAs, we have designed and developed zwitterion-coated exceedingly small superparamagnetic iron oxide nanoparticles (ZES-SPIONs) consisting of ∼3-nm inorganic cores and ∼1-nm ultrathin hydrophilic shell. These ZES-SPIONs are free of Gd and show a high T1 contrast power. We demonstrate the potential of ZES-SPIONs in preclinical MRI and magnetic resonance angiography.

Evolution of the Single-Nanocrystal Photoluminescence Linewidth with Size and Shell: Implications for Exciton-Phonon Coupling and the Optimization of Spectral Linewidths.

The optimization of photoluminescence spectral linewidths in semiconductor nanocrystal preparations involves minimizing both the homogeneous and inhomogeneous contributions to the ensemble spectrum. Although the inhomogeneous contribution can be controlled by eliminating interparticle inhomogeneities, far less is known about how to synthetically control the homogeneous, or single-nanocrystal, spectral linewidth. Here, we use solution photon-correlation Fourier spectroscopy (S-PCFS) to measure how the sample-averaged single-nanocrystal emission linewidth of CdSe core and core/shell nanocrystals change with systematic changes in the size of the cores and the thickness and composition of the shells. We find that the single-nanocrystal linewidth at room temperature is heavily influenced by the nature of the CdSe surface and the epitaxial shell, which have a profound impact on the internal electric fields that affect exciton-phonon coupling. Our results explain the wide variations, both experimental and theoretical, in the magnitude and size dependence in previous reports on exciton-phonon coupling in CdSe nanocrystals. Moreover, our findings offer a general pathway for achieving the narrow spectral linewidths required for many applications of nanocrystals.

Identifying and Eliminating Emissive Sub-bandgap States in Thin Films of PbS Nanocrystals.

Chemical oxidation of under-charged Pb atoms reduces the density of trap states by a factor of 40 in films of colloidal PbS quantum dots for devices. These emissive sub-bandgap states are a byproduct of several standard ligand-exchange procedures. X-ray photoelectron spectro-scopy measurements and density function theory simulations demonstrate that they are associated with under-charged Pb.

Leukoencephalopathic changes on magnetic resonance imaging associated with a thermogenic dietary supplement (Thermatrim).

Acute toxic leukoencephalopathy can be caused by exposure to many compounds. Reversibility has been described in some cases with prompt recognition and withdrawal of the offending agent. Its association with a thermogenic supplement has never been reported. We describe two such cases in young women taking a commercially available thermogenic dietary supplement who presented with acute neurologic deficits and a common magnetic resonance imaging pattern.

Magneto-fluorescent core-shell supernanoparticles.

Magneto-fluorescent particles have been recognized as an emerging class of materials that exhibit great potential in advanced applications. However, synthesizing such magneto-fluorescent nanomaterials that simultaneously exhibit uniform and tunable sizes, high magnetic content loading, maximized fluorophore coverage at the surface and a versatile surface functionality has proven challenging. Here we report a simple approach for co-assembling magnetic nanoparticles with fluorescent quantum dots to form colloidal magneto-fluorescent supernanoparticles. Importantly, these supernanoparticles exhibit a superstructure consisting of a close-packed magnetic nanoparticle 'core', which is fully surrounded by a 'shell' of fluorescent quantum dots. A thin layer of silica coating provides high colloidal stability and biocompatibility, and a versatile surface functionality. We demonstrate that after surface pegylation, these silica-coated magneto-fluorescent supernanoparticles can be magnetically manipulated inside living cells while being optically tracked. Moreover, our silica-coated magneto-fluorescent supernanoparticles can also serve as an in vivo multi-photon and magnetic resonance dual-modal imaging probe.

Compact zwitterion-coated iron oxide nanoparticles for biological applications.

The potential of superparamagnetic iron oxide nanoparticles (SPIONs) in various biomedical applications, including magnetic resonance imaging (MRI), sensing, and drug delivery, requires that their surface be derivatized to be hydrophilic and biocompatible. We report here the design and synthesis of a compact and water-soluble zwitterionic dopamine sulfonate (ZDS) ligand with strong binding affinity to SPIONs. After ligand exchange, the ZDS-coated SPIONs exhibit small hydrodynamic diameters, and stability with respect to time, pH, and salinity. Furthermore, small ZDS coated SPIONs were found to have a reduced nonspecific affinity (compared to negatively charged SPIONs) toward serum proteins; streptavidin/dye functionalized SPIONs were bioactive and thus specifically targeted biotin receptors.

[Prognostic factors for survival in patients with transitional bladder cancer treated with radical cystectomy]. / Factores pronósticos en la supervivencia de los pacientes con carcinoma transicional de vejiga tratados con cistectomía radical.

PURPOSE: To recognize clinical and pathological variables that influence in bladder cancer specific mortality in patients with transitional bladder cancer treated with radical cystectomy. MATERIAL AND METHOD: Retrospective analysis of 333 patients with transitional bladder cancer treated with radical cystectomy. Variables included during pre-cystectomy, peri-cystectomy and post-cystectomy period were analyzed. Four groups were defined based on pathological state: a) Organ-confine bladder cancer without lymph node metastasis (pT0-2, pN0); b) Extravesical desease without lymph node metastasis (pT3-4, pN0); c) Bladder cancer with lymph node metastasis (pT0-4, pN+); d) No data of lymph node affection (pT0-4, pNx). Univariate analysis and two models of multivariate analysis were performed including the risk group as a variable in one the latest. RESULTS: Mean follow up was 52.6 +/- 51 (2-221) months with a median of 31 months. Pathological state pT0 was observed in 7.2% of the patients, 12% were pT1, 26.7% pT2, 34.5% pT3 and 10.5% pT4. Lymph node metastasis was detected in 20.7% of the patients. Lymph node metastasis increased according to pathological state rises. Five and 10 years specific survival was 57% and 54% respectively. CONCLUSIONS: Local pathological state, lymph node status and risk groups were independent predictive factors for bladder cancer specific survival. Risk group association is a reliable method to predict bladder cancer specific survival and to identify the suitable patient group to get benefit from adjuvant therapy.

Factores pronósticos en la supervivencia de los pacientes con carcinoma transicional de vejiga tratados con cistectomía radical / Prognostic factors for survival in patients with transitional baldder cancer treated with radical cystectomy

Objetivo: conocer las variables clínicas y patológicas que influyen en la mortalidad cáncer-específica de los pacientes con carcinoma transicional de vejiga tratados mediante cistectomía radical (CR).Material y Método: análisis retrospectivo de 333 pacientes con cáncer transicional de vejiga tratados mediante CR. Se analizaron variables agrupadas en el período pre-cistectomía, peri-cistectomía y de seguimiento. Se definieron 4 grupos de riesgo en función del estadio patológico: a) Enfermedad localizada vesical sin afectación ganglionar (pT0-2, pN0); b) Enfermedad extravesical sin afectación ganglionar (pT3-4, pN0); c) Enfermedad con afectación ganglionar (pT0-4, pN+); d) Sin datos sobre la afectación ganglionar (pT0-4, pNx). Realizamos un análisis univariante y dos modelos de multivariante con y sin los grupos de riesgo descritos. Resultados: La media de seguimiento de la serie fue de 52,6 ± 51 (2-221) meses con una mediana de 31 meses. Un 7,2%de los pacientes presentó estadio pT0, 12% pT1, 26,7% pT2, 34,5% pT3 y un 19,5% pT4. El 20,7% de los pacientes tenían metástasis ganglionares (pN+). La supervivencia cáncer específica a los 5 años fue del 57% y del 54% a los 10 años. Conclusiones: El estadio patológico, la afectación ganglionar y los grupos de riesgo se comportaron como factores predictivos independientes para la supervivencia cáncer-específica. La asociación por grupos de riesgo permite predecir de una forma más fiable el riesgo de fallecer por cáncer de vejiga e identificar a los pacientes en los que la cistectomía resulta un tratamiento insuficiente y que se podrían beneficiar de un tratamiento adyuvante (AU)

Purpose: to recognize clinical and pathological variables that influence in bladder cancer specific mortality in patients with transitional bladder cancer treated with radical cystectomy. Matherial and Method: retrospective analysis of 333 patients with transitional bladder cancer treated with radical cystectomy. Variables included during pre-cystectomy, peri-cystectomy and post-cystectomy period were analyzed. Four groups were defined based on pathological state: a) Organ-confine bladder cancer without lymph node metastasis(pT0-2, pN0); b) Extravesical desease without lymph node metastasis (pT3-4, pN0); c) Bladder cancer with lymph nodemetastasis (pT0-4, pN+); d) No data of lymph node affection (pT0-4, pNx). Univariate analysis and two models of multivariate analysis were performed including the risk group as a variable in one the latest. Results: Mean follow up was 52.6 ± 51 (2-221) months with a median of 31 months. Pathological state pT0 was observed in 7.2% of the patients, 12% were pT1, 26.7% pT2, 34.5% pT3 and 10.5% pT4. Lymph node metastasis was detected in20.7% of the patients. Lymph node metastasis increased according to pathological state rises. Five and 10 years specific survival was 57% and 54% respectively. Conclusions: Local pathological state, lymph node status and risk groups were independent predictive factors for bladder cancer specific survival. Risk group association is a reliable method to predict bladder cancer specific survival and to identify the suitable patient group to get benefit from adjuvant therapy (AU)