Thermochromic Printable and Multicolor Polymeric Composite Based on Hybrid Organic-Inorganic Perovskite

Hybrid organic-inorganic perovskites (PVKs) are among the most promising materials for optoelectronic applications thanks to their outstanding photophysical properties and easy synthesis. Herein, a new PVK-based thermochromic composite is demonstrated. It can reversibly switch from a transparent state (transmittance > 80%) at room temperature to a colored state (transmittance < 10%) at high temperature, with very fast kinetics, taking only a few seconds to go from the bleached to the colored state (and vice versa). X-ray diffraction, Fourier-transform infrared spectroscopy, differential scanning calometry, rheological, and optical measurements carried out during heating/cooling cycles reveal that thermochromism in the material is based on a reversible process of PVK disassembly/assembly mediated by intercalating polymeric chains, through the formation and breaking of hydrogen bonds between polymer and perovskite. Therefore, differently from other thermochromic perovskites, that generally work with the adsorption/desorption of volatile molecules, the system is able to perform several heating/cooling cycles regardless of environmental conditions. The color and transition temperature (from 70 to 120 °C) can be tuned depending on the type of perovskite. Moreover, this thermochromic material is printable and can be deposited by cheap techniques, paving the way for a new class of smart coatings with an unprecedented range of colors.

Role of a corrugated Dion-Jacobson 2D perovskite as an additive in 3D MAPbBr3 perovskite-based light emitting diodes

Metal halide perovskites represent an intriguing class of materials, and a very promising approach to tune the properties of optoelectronic devices and improve their performance involves the implementation of architectures based on mixed 3D and 2D perovskites. In this work, we investigated the use of a corrugated 2D Dion-Jacobson perovskite as an additive to a classical 3D MAPbBr3 perovskite for applications in light-emitting diodes. Taking advantage of the properties of this emerging class of materials, we studied the effect of a 2D 2-(dimethylamino)ethylamine (DMEN)-based perovskite on the morphological, photophysical, and optoelectronic properties of 3D perovskite thin films. We used α-DMEN perovskite both in a mixture with MAPbBr3 creating mixed 2D/3D phases and as a passivating thin layer deposited on the top of a 3D perovskite polycrystalline film. We observed a beneficial modulation of the thin film surface, a blue shift in the emission spectrum, and enhanced device performance.

Collagen Membrane as Water-Based Gel Electrolyte for Electrochromic Devices

Bio-based polymers are attracting great interest due to their potential for several applications in place of conventional polymers. In the field of electrochemical devices, the electrolyte is a fundamental element that determines their performance, and polymers represent good candidates for developing solid-state and gel-based electrolytes toward the development of full-solid-state devices. In this context, the fabrication and characterization of uncrosslinked and physically cross-linked collagen membranes are reported to test their potential as a polymeric matrix for the development of a gel electrolyte. The evaluation of the membrane's stability in water and aqueous electrolyte and the mechanical characterization demonstrated that cross-linked samples showed a good compromise in terms of water absorption capability and resistance. The optical characteristics and the ionic conductivity of the cross-linked membrane, after overnight dipping in sulfuric acid solution, demonstrated the potential of the reported membrane as an electrolyte for electrochromic devices. As proof of concept, an electrochromic device was fabricated by sandwiching the membrane (after sulfuric acid dipping) between a glass/ITO/PEDOT:PSS substrate and a glass/ITO/SnO₂ substrate. The results in terms of optical modulation and kinetic performance of such a device demonstrated that the reported cross-linked collagen membrane could represent a valid candidate as a water-based gel and bio-based electrolyte for full-solid-state electrochromic devices.

Colloidal Bismuth Chalcohalide Nanocrystals

Here we present a colloidal approach to synthesize bismuth chalcohalide nanocrystals (BiEX NCs, in which E=S, Se and X=Cl, Br, I). Our method yields orthorhombic elongated BiEX NCs, with BiSCl crystallizing in a previously unknown polymorph. The BiEX NCs display a composition‐dependent band gap spanning the visible spectral range and absorption coefficients exceeding 10⁵ cm⁻¹. The BiEX NCs show chemical stability at standard laboratory conditions and form colloidal inks in different solvents. These features enable the solution processing of the NCs into robust solid films yielding stable photoelectrochemical current densities under solar‐simulated irradiation. Overall, our versatile synthetic protocol may prove valuable in accessing colloidal metal chalcohalide nanomaterials at large and contributes to establish metal chalcohalides as a promising complement to metal chalcogenides and halides for applied nanotechnology.

Electrochromic evaluation of airbrushed water-dispersible W18O49nanorods obtained by microwave-assisted synthesis

Motivated by the technological relevance of tungsten oxide nanostructures as valuable materials for energy saving technology, electrochemical and electrochromic characteristics of greener processed nanostructured W₁₈O₄₉-based electrodes are discussed in this work. For the purpose, microwave-assisted water-dispersible W₁₈O₄₉nanorods have been synthesized and processed into nanostructured electrodes. An airbrushing technique has been adopted as a cost-effective large-area scalable methodology to deposit the W₁₈O₄₉nanorods onto conductive glass. This approach preserves the morphological and crystallographic habit of native nanorods and allows highly homogeneous transparent coating where good electronic coupling between nanowires is ensured by a mild thermal treatment (250 °C, 30 min). Morphological and structural characteristics of active material were investigated from the synthesis to the nanocrystal deposition process by transmission and scanning electron microscopy, x-ray diffraction, atomic force microscopy and Raman spectroscopy. The as-obtained nanostructured film exhibited good reversible electrochemical features through several intercalation-deintercalation cycles. The electrochromic properties were evaluated on the basis of spectro-electrochemical measurements and showed significant optical contrast in the near-infrared region and high coloration efficiency at 550 nm.

Pseudocapacitive behaviour in sol-gel derived electrochromic titania nanostructures

Nanostructured thin films are widely investigated for application in multifunctional devices thanks to their peculiar optoelectronic properties. In this work anatase TiO₂ nanoparticles (average diameter 10 nm) synthesised by a green aqueous sol-gel route are exploited to fabricate optically active electrodes for pseudocapacitive-electrochromic devices. In our approach, highly transparent and homogeneous thin films having a good electronic coupling between nanoparticles are prepared. These electrodes present a spongy-like nanostructure in which the dimension of native nanoparticles is preserved, resulting in a huge surface area. Cyclic voltammetry studies reveal that there are significant contributions to the total stored charge from both intercalation capacitance and pseudocapacitance, with a remarkable 50% of the total charge deriving from this second effect. Fast and reversible colouration occurs, with an optical modulation of ∼60% in the range of 315-1660 nm, and a colouration efficiency of 25.1 cm² C^-1 at 550 nm. This combination of pseudocapacitance and electrochromism makes the sol-gel derived titania thin films promising candidates for multifunctional 'smart windows'.

Magnesium sulphate in the Emergency Department: an old, new friend

With our study, we searched the medical literature to find magnesium (Mg) correlation with Emergency situations or its use in Emergency Medicine. Our aim is to fill the gap that we find in our daily routine between Mg studies on its role in Emergency and the real conception that doctors have of it in medical practice. We searched the literature for terms as magnesium or magnesium sulphate, magnesium in emergency, eclampsia, arrhythmias, acute asthma exacerbation, magnesium, and pediatric population. After a thorough research, we divided our discoveries into chapters to sort out a large amount often discordant articles.

Reliability of Protective Coatings for Flexible Piezoelectric Transducers in Aqueous Environments

Electronic devices used for marine applications suffer from several issues that can compromise their performance. In particular, water absorption and permeation can lead to the corrosion of metal parts or short-circuits. The added mass due to the absorbed water affects the inertia and durability of the devices, especially for flexible and very thin micro-systems. Furthermore, the employment of such delicate devices underwater is unavoidably subjected to the adhesion of microorganisms and formation of biofilms that limit their reliability. Thus, the demand of waterproofing solutions has increased in recent years, focusing on more conformal, flexible and insulating coatings. This work introduces an evaluation of different polymeric coatings (parylene-C, poly-dimethyl siloxane (PDMS), poly-methyl methacrylate (PMMA), and poly-(vinylidene fluoride) (PVDF)) aimed at increasing the reliability of piezoelectric flexible microdevices used for sensing water motions or for scavenging wave energy. Absorption and corrosion tests showed that Parylene-C, while susceptible to micro-cracking during prolonged oscillating cycles, exhibits the best anti-corrosive behavior. Parylene-C was then treated with oxygen plasma and UV/ozone for modifying the surface morphology in order to evaluate the biofilm formation with different surface conditions. A preliminary characterization through a laser Doppler vibrometer allowed us to detect a reduction in the biofilm mass surface density after 35 days of exposure to seawater.

Tunable Near-Infrared Localized Surface Plasmon Resonance of F, In-Codoped CdO Nanocrystals

Nanocrystals (NCs) of transparent conducting oxides with a localized surface plasmon resonance (LSPR) in the near-infrared (NIR) spectral region show promising electrochromic properties for the development of a new generation of dynamic "smart windows". In this regard, we exploit thin films of F, In-codoped CdO (FICO) NCs as active coatings for electrochromic devices. The control over the dopants concentration in FICO NCs results in fine tuning of their LSPR across the NIR region of the electromagnetic spectrum. Highly transparent mesoporous electrodes were prepared from colloidal FICO NCs by in situ ligand exchange of the pristine organic capping ligands. This approach preserves the optical and electrical properties of native NCs and delivers highly homogeneous, nonscattering films with a good electronic coupling between the NCs. We achieved a dynamic control over the LSPR frequency by reversible electrochemical doping, hence a spectrally selective modulation of the optical transmittance in the NIR region of the solar spectrum, which carries nearly 50% of the whole solar heat. Spectroelectrochemical characterization, coloration efficiency, and switching kinetics results indicate that thin film based on FICO NCs are potential candidates for plasmonic electrochromic applications. Moreover, the high electron mobility and wide optical bandgap of FICO makes NCs of this material suitable for large-area devices capable of dynamically controlling the heat load coming from the solar infrared radiation, without affecting the visible light transmittance.

Dual Band Electrochromic Devices Based on Nb-Doped TiO2 Nanocrystalline Electrodes

The reliable exploitation of localized surface plasmon resonance in transparent conductive oxides is being pursued to push the developement of an emerging class of advanced dynamic windows, which offer the opportunity to selectively and dynamically control the intensity of the incoming thermal radiation without affecting visible transparency. In this view, Nb-doped TiO₂ colloidal nanocrystals are particularly promising, as they have a wide band gap and their plasmonic features can be finely tailored across the near-infrared region by varying the concentration of dopants. Four batches of Nb-doped TiO₂ nanocrystals with different doping levels (from 0% to 15% of niobium content) have been used here to prepare highly transparent mesoporous electrodes for near-infrared selective electrochromic devices, capable of dynamically modulating the intensity of the transmitted radiation upon the application of a relatively small bias voltage. An engineered dual band electrochromic device (made of 10%-Nb-doped TiO₂ nanocrystals) has been eventually fabricated. It was shown to provide two complementary spectroelectrochemical responses, which can be independently controlled through the intensity of the applied potential: a large variation of the optical transmittance in the near-infrared region (by the intensification of the localized surface plasmon scattering) was achievable in the 0-3 V voltage window, reaching values greater than 64% in the spectral range from 800 to 2000 nm, whereas the visible absorption could also be intensively varied at higher potentials (from 3 to 4 V), driven by Li intercalation into the TiO₂ anatase lattice.

Near-infrared selective dynamic windows controlled by charge transfer impedance at the counter electrode

Recent developments in the exploitation of transparent conductive oxide nanocrystals paved the way to the realization of a new class of electrochemical systems capable of selectively shielding the infrared heat loads carried by sunlight and prospected the blooming of a key enabling technology to be implemented in the next generation of "zero-energy" building envelopes. Here we report the fabrication of a set of electrochromic devices embodying an engineered nanostructured electrode made by high aspect-ratio tungsten oxide nanorods, which allow for selectively and dynamically controlling sunlight transmission over the near-infrared to visible range. Varying the intensity of applied voltage makes the spectral response of the device change across three different optical regimes, namely fully transparent, near-infrared only blocking and both visible and near-infrared blocking. It is demonstrated that the degree of reversible modulation of the thermal radiation entering the glazing element can approach a remarkable 85%, accompanied by only a modest reduction in the luminous transmittance.

Tetracoordinated Bis-phenanthroline Copper-Complex Couple as Efficient Redox Mediators for Dye Solar Cells

A tetracoordinated redox couple, made by [Cu(2-mesityl-4,7-dimethyl-1,10-phenanthroline)2][PF6], 1, and its Cu(II) form [Cu(2-mesityl-4,7-dimethyl-1,10-phenanthroline)2][PF6]2, 2, has been synthesized, and its electrochemical and photochemical features have been investigated and compared with those of a previously published Cu(2+)/Cu(+) redox shuttle, namely, [Cu(2,9-dimethyl-1,10-phenanthroline)2][PF6], 3, and its pentacoordinated oxidized form [Cu(2,9-dimethyl-1,10-phenanthroline)2Cl][PF6], 4. The detrimental effect of the fifth Cl(-) ancillary ligand on the charge transfer kinetics of the redox shuttles has been exhaustively demonstrated. Appropriately balanced Cu-based electrolytes have been then formulated and tested in dye solar cells in combination with a π-extended benzothiadiazole dye. The bis-phenanthroline Cu-complexes, 1 and 2, have been found to provide an overall 4.4% solar energy conversion efficiency, which is more than twice that of the literature benchmark couple, 3 and 4, employing a Cl-coordinated oxidized species and even comparable with the performances of a I(-)/I3(-) electrolyte of analogous concentration. A fast counter-electrode reaction, due to the excellent electrochemical reversibility of 2, and a high electron collection efficiency, allowed through the efficient dye regeneration kinetics exerted by 1, represents two major characteristics of these copper-based electron mediators and may constitute a pivotal step toward the development of a next generation of copper-based efficient iodine-free redox shuttles.

NiO/MAPbI(3-x)Clx/PCBM: a model case for an improved understanding of inverted mesoscopic solar cells

A spectroscopic investigation focusing on the charge generation and transport in inverted p-type perovskite-based mesoscopic (Ms) solar cells is provided in this report. Nanocrystalline nickel oxide and PCBM are employed respectively as hole transporting scaffold and hole blocking layer to sandwich a perovskite light harvester. An efficient hole transfer process from perovskite to nickel oxide is assessed, through time-resolved photoluminescence and photoinduced absorption analyses, for both the employed absorbing species, namely MAPbI3-xClx and MAPbI3. A striking relevant difference between p-type and n-type perovskite-based solar cells emerges from the study.

Influence of porphyrinic structure on electron transfer processes at the electrolyte/dye/TiO₂ interface in PSSCs: a comparison between meso push-pull and β-pyrrolic architectures

Time-resolved photophysical and photoelectrochemical investigations have been carried out to compare the electron transfer dynamics of a 2-β-substituted tetraarylporphyrinic dye (ZnB) and a 5,15-meso-disubstituted diarylporphyrinic one (ZnM) at the electrolyte/dye/TiO2 interface in PSSCs. Although the meso push-pull structural arrangement has shown, up to now, to have the best performing architecture for solar cell applications, we have obtained superior energy conversion efficiencies for ZnB (6.1%) rather than for ZnM (3.9%), by using the I(-)/I3(-)-based electrolyte. To gain deeper insights about these unexpected results, we have investigated whether the intrinsic structural features of the two different porphyrinic dyes can play a key role on electron transfer processes occurring at the dye-sensitized TiO2 interface. We have found that charge injection yields into TiO2 are quite similar for both dyes and that the regeneration efficiencies by I(-), are also comparable and in the range of 75-85%. Moreover, besides injection quantum yields above 80%, identical dye loading, for both ZnB and ZnM, has been evidenced by spectrophotometric measurements on transparent thin TiO2 layers after the same adsorption period. Conversely, major differences have emerged by DC and AC (electrochemical impedance spectroscopy) photoelectrochemical investigations, pointing out a slower charge recombination rate when ZnB is adsorbed on TiO2. This may result from its more sterically hindered macrocyclic core which, besides guaranteeing a decrease of π-staking aggregation of the dye, promotes a superior shielding of the TiO2 surface against charge recombination involving oxidized species of the electrolyte.

Enhancing dye-sensitized solar cell performances by molecular engineering: highly efficient π-extended organic sensitizers

This study deals with the synthesis and characterization of two π-extended organic sensitizers (G1 and G2) for applications in dye-sensitized solar cells. The materials are designed with a D-A-π-A structure constituted by i) a triarylamine group as the donor part, ii) a dithienyl-benzothiadiazole chromophore followed by iii) a further ethynylene-thiophene (G1) or ethynylene-benzene (G2) π-spacer and iv) a cyano-acrylic moiety as acceptor and anchoring part. An unusual structural extension of the π-bridge characterizes these structures. The so-configured sensitizers exhibit a broad absorption profile, the origin of which is supported by density functional theory. The absence of hypsochromic shifts as a consequence of deprotonation as well as notable optical and electrochemical stabilities are also observed. Concerning the performances in devices, electrochemical impedance spectroscopy indicates that the structural modification of the π-spacer mainly increases the electron lifetime of G2 with respect to G1. In devices, this feature translates into a superior power conversion efficiency of G2, reaching 8.1%. These results are comparable to those recorded for N719 and are higher with respect to literature congeners, supporting further structural engineering of the π-bridge extension in the search for better performing π-extended organic sensitizers.

Combined strategy to realize efficient photoelectrodes for low temperature fabrication of dye solar cells

We implemented a low-temperature approach to fabricate efficient photoanodes for dye-sensitized solar cells, which combines three different nanoarchitectures, namely, a highly conductive and highly transparent AZO film, a thin TiO2-blocking layer, and a mesoporous TiO2 nanorod-based working electrode. All the components were processed at T≤200°C. Both the AZO and the TiO2 blocking layers were deposited by reactive sputtering, whereas the TiO2 nanorods were synthesized by surfactant-assisted wet-chemical routes and processed into photoelectrodes in which the native geometric features assured uniform mesoporous structure with effective nanocrystal interconnectivity suitable to maximize light harvesting and electron diffusion. Because of the optimized structure of the TiO2-blocking/AZO bilayer, and thanks to the good adhesion of the TiO2 nanorods over it, a significant enhancement of the charge recombination resistance was demonstrated, this laying on the basis of the outstanding power conversion efficiency achievable through the use of this photoanode's architecture: a value of 4.6% (N719) was achieved with a 4-μm-thick electrode processed at T=200°C. This value noticeably overcomes the current literature limit got on AZO-based cells (N719), which instead use Nb-doped and thicker blocking layers, and thicker nanostructured photoanodes, which have been even sintered at higher temperatures (450-500°C).

Shape and morphology effects on the electronic structure of TiO(2) nanostructures: from nanocrystals to nanorods

We carry out an accurate computational analysis on the nature and distribution of electronic trap states in shape-tailored anatase TiO2 structures, investigating the effect of the morphology on the electronic structure. Linear nanocrystal models up to 6 nm in length with various morphologies, reproducing both flattened and elongated rod-shaped TiO2 nanocrystals, have been investigated by DFT calculations, to clarify the effect of the crystal facet percentage on the nanocrystal electronic structure, with particular reference to the energetics and distribution of trap states. The calculated densities of states below the conduction band edge have been very well fitted assuming an exponential distribution of energies and have been correlated with experimental capacitance data. In good agreement with the experimental phenomenology our calculations show that elongated rod-shaped nanocrystals with higher values of the ratio between (100) and (101) facets exhibit a relatively deeper distribution of trap states. Our results point at the crucial role of the nanocrystal morphology on the trap state density, highlighting the importance of a balance between the low-energy (101) and high-energy (100)/(001) surface facets in individual TiO2 nanocrystals.

Ultrathin TiO₂(B) nanorods with superior lithium-ion storage performance

The peculiar architecture of a novel class of anisotropic TiO2(B) nanocrystals, which were synthesized by an surfactant-assisted nonaqueous sol-gel route, was profitably exploited to fabricate highly efficient mesoporous electrodes for Li storage. These electrodes are composed of a continuous spongy network of interconnected nanoscale units with a rod-shaped profile that terminates into one or two bulgelike or branch-shaped apexes spanning areas of about 5 × 10 nm(2). This architecture transcribes into a superior cycling performance (a charge capacitance of 222 mAh g(-1) was achieved by a carbon-free TiO2(B)-nanorods-based electrode vs 110 mAh g(-1) exhibited by a comparable TiO2-anatase electrode) and good chemical stability (more than 90% of the initial capacity remains after 100 charging/discharging cycles). Their outstanding lithiation/delithiation capabilities were also exploited to fabricate electrochromic devices that revealed an excellent coloration efficiency (130 cm(2) C(-1) at 800 nm) upon the application of 1.5 V as well as an extremely fast electrochromic switching (coloration time ∼5 s).

Highly efficient photoanodes for dye solar cells with a hierarchical meso-ordered structure

An engineered bi-layered photoelectrode for dye solar cells has been developed which profitably employs two synergistic meso-ordered components, namely a thin meso-ordered TiO2 film and a main microparticles-based photoelectrode. The former has been deposited as an interfacial layer at the FTO-coated substrate and suppresses the back-transport reaction by blocking direct contact between the electrolyte and conductive oxide. The latter is made of hierarchical micro- and nano-structured building blocks prepared by template synthesis, which permits efficient light scattering without sacrificing the internal surface area. The optimization of light harvesting and charge recombination dynamics allowed us to achieve as high energy conversion efficiency as 9.7%.

Self-cleaning organic/inorganic photo-sensors

We present the fabrication of a multifunctional, hybrid organic-inorganic micropatterned device, which is capable to act as a stable photosensor and, at the same time, displaying inherent superhydrophobic self-cleaning wetting characteristics. In this framework several arrays of epoxy photoresist square micropillars have been fabricated on n-doped crystalline silicon substrates and subsequently coated with a poly(3-hexylthiophene-2,5-diyl) (P3HT) layer, giving rise to an array of organic/inorganic p-n junctions. Their photoconductivity has been measured under a solar light simulator at different illumination intensities. The current-voltage (I-V) curves show high rectifying characteristics, which are found to be directly correlated with the illumination intensity. The photoresponse occurs in extremely short times (within few tens of milliseconds range). The influence of the interpillar distance on the I-V characteristics of the sensors is also discussed. Moreover, the static and dynamic wetting properties of these organic/inorganic photosensors can be easily tuned by changing the pattern geometry. Measured static water contact angles range from 125° to 164°, as the distance between the pillars is increased from 14 to 120 μm while the contact angle hysteresis decreases from 36° down to 2°.

Psychiatric emergencies (part III): psychiatric symptoms resulting from organic diseases

An exhaustive review on the organic illnesses presenting with psychiatric manifestations, properly defined pseudopsychiatric emergencies, is presented. A systematic classification of the numerous organic causes of psychiatric disorders, based on authors' experience and literature revision, is carefully analysed, and their suitable diagnostic management in emergency setting is proposed. Moreover, the role of bedside ultrasonography in Emergency Department is emphasized. The underlying pathogenetic mechanisms are separately discussed. A particular significance is given to "neuropsychological studies", displaying the complex connection between the central nervous system and the endocrine system. The role of immune system in influencing the central nervous system, explaining the model of "sickness behaviour" in inflammatory disease, is also described, according to recent reports of "psychoneuroimmunology". Moreover, the immune-mediated mechanism explaining how neoplasm can influence brain function in the "paraneoplastic syndromes" is shown. In order to facilitate the teaching method, organic illnesses presenting with acute psychic manifestations or mimicking specific psychiatric disorders are subdivided into three groups: (1) Endocrine and metabolic disorders and deficiency states; (2) Internal diseases; (3) Neurologic disorders.

Psychiatric emergencies (part I): psychiatric disorders causing organic symptoms

Psychiatric emergencies are conditions that mostly destabilize the already frenetic activity of the Emergency Department. Sometimes the emergency is clearly referable to primitive psychiatric illness. Other times, psychiatric and organic symptoms can independently coexist (comorbidity), or develop together in different conditions of substance abuse, including alcohol and prescription drugs. Differentiating between substance induced and pre-existing psychiatric disorder (dual diagnosis) may be difficult, other than controversial issue. Finally, an organic disease can hide behind a psychiatric disorder (pseudopsychiatric emergency). In this review (part I), psychiatric disorders that occur with organic symptoms are discussed. They include: (1) anxiety, conversion and psychosomatic disorders, and (2) simulated diseases. The physiologic mechanisms of the stress reaction, divided into a dual neuro-hormonal response, are reviewed in this section: (1) activation of the sympathetic nervous system and adrenal medulla with catecholamine production (rapid response), and (2) activation of the hypothalamic-pituitary-adrenal axis with cortisol production (slow response). The concept of the fight-or-flight response, its adaptive significance and the potential evolution in paralyzing response, well showing by Yerkes-Dodson curve, is explained. Abnormal short- and long-term reactions to stress evolving toward well codified cluster of trauma and stressor-related disorders, including acute stress disorder, adjustment disorder and post-traumatic stress disorder, are examined. A brief review of major psychiatric disorder and related behaviour abnormalities, vegetative symptoms and cognitive impairment, according to DMS IV-TR classification, are described. Finally, the reactive psychic symptoms and behavioral responses to acute or chronic organic disease, so called "somatopsychic disorders", commonly occurring in elderly and pediatric patients, are presented. The specific conditions of post-operative and intensive care unit patients, and cancer and HIV positive population are emphasized.

Psychiatric emergencies (part II): psychiatric disorders coexisting with organic diseases

In this Part II psychiatric disorders coexisting with organic diseases are discussed. "Comorbidity phenomenon" defines the not univocal interrelation between medical illnesses and psychiatric disorders, each other negatively influencing morbidity and mortality. Most severe psychiatric disorders, such as schizophrenia, bipolar disorder and depression, show increased prevalence of cardiovascular disease, related to poverty, use of psychotropic medication, and higher rate of preventable risk factors such as smoking, addiction, poor diet and lack of exercise. Moreover, psychiatric and organic disorders can develop together in different conditions of toxic substance and prescription drug use or abuse, especially in the emergency setting population. Different combinations with mutual interaction of psychiatric disorders and substance use disorders are defined by the so called "dual diagnosis". The hypotheses that attempt to explain the psychiatric disorders and substance abuse relationship are examined: (1) common risk factors; (2) psychiatric disorders precipitated by substance use; (3) psychiatric disorders precipitating substance use (self-medication hypothesis); and (4) synergistic interaction. Diagnostic and therapeutic difficulty concerning the problem of dual diagnosis, and legal implications, are also discussed. Substance induced psychiatric and organic symptoms can occur both in the intoxication and withdrawal state. Since ancient history, humans selected indigene psychotropic plants for recreational, medicinal, doping or spiritual purpose. After the isolation of active principles or their chemical synthesis, higher blood concentrations reached predispose to substance use, abuse and dependence. Abuse substances have specific molecular targets and very different acute mechanisms of action, mainly involving dopaminergic and serotoninergic systems, but finally converging on the brain's reward pathways, increasing dopamine in nucleus accumbens. The most common substances producing an addiction status may be assembled in depressants (alcohol, benzodiazepines, opiates), stimulants (cocaine, amphetamines, nicotine, caffeine, modafinil), hallucinogens (mescaline, LSD, ecstasy) and other substances (cannabis, dissociatives, inhalants). Anxiety disorders can occur in intoxication by stimulants, as well as in withdrawal syndrome, both by stimulants and sedatives. Substance induced mood disorders and psychotic symptoms are as much frequent conditions in ED, and the recognition of associated organic symptoms may allow to achieve diagnosis. Finally, psychiatric and organic symptoms may be caused by prescription and doping medications, either as a direct effect or after withdrawal. Adverse drug reactions can be divided in type A, dose dependent and predictable, including psychotropic drugs and hormones; and type B, dose independent and unpredictable, usually including non psychotropic drugs, more commonly included being cardiovascular, antibiotics, anti-inflammatory and antineoplastic medications.

Acetaminophen plus codeine compared to ketorolac in polytrauma patients

INTRODUCTION

The management of pain in polytrauma patients is mandatory. While non-steroidal anti-inflammatory drugs (NSAIDs) represent the most used drugs in polytrauma patients, their use may be associated with an increased risk of haemorrhage. Opioids may represent a valid alternative to NSAIDs either alone or in combination with acetaminophen. Whether their efficacy is comparable to that produced by NSAIDs in polytrauma patients has never been studied.

PATIENTS AND METHODS

60 polytrauma patients were enrolled for this study. 30 patients were treated with acetaminophen 1000 mg plus codeine 60 mg tid for 24 hours (Group A), while the remaining 30 with ketorolac 10 mg qid for 24 hours (Group B). Pain intensity has been evaluated using an analogical visual scale (VAS) ranging from 0 (no pain) to 10 (very severe pain). The level of pain was valuated at enrolment (TO) as well as after 2 (T2), 12 (T12) and 24 (T24) hours from the starting of the analgesic therapy. Results obtained by the group A were compared with those reported by the group B.

RESULTS

T0: Group A mean score was 6.4 +/- 1.5 compared with 6.6 +/- 1.5 of Group B (p= ns); T2: Group A mean score was 3.4 +/- 2.8, compared with 3.5 +/- 2.4 of group B (p = ns); T12: Group A mean score was 3.4 +/- 3.4, compared with 3.5 +/- 3 of Gorup B (p = ns); T24: Group A mean score was 2.9 +/- 1.5, compared to 3.0 +/- 1.6 of Group B (p = ns). All those drugs determined a significant reduction of pain intensity during the course of therapy.

CONCLUSIONS

Acetaminophen plus codeine is effective in pain control in polytrauma patients at least in our series. It may represent a valid alternative to NSAIDs, especially in patients with a documented haemorrhage or with a high hemorrhagic risk.

The proposal of an integrated ultrasonographic approach into the ALS algorithm for cardiac arrest: the PEA protocol

BACKGROUND AND OBJECTIVE

Guidelines on cardiac arrest (CA) recommend the prompt beginning of cardio-pulmonary resuscitation (CPR) and the identification and correction of reversible causes. This article deals with the application of clinical ultrasonography (US) in resuscitation, presenting a simple codified US protocol usable during CPR to recognize reversible causes of CA. EVIDENCE ON US IN CA AND STATE OF THE ART: Emergency US is a bedside, point-of-care, focused diagnostic procedure with aim to complete the physical examination. It is performed by emergency physician everywhere to answer briefly important clinical questions. Several trials recently experimented US employment during advanced life support, demonstrating its feasibility without delaying CPR.

PERSPECTIVES

The PEA Protocol: We propose a simplified US protocol for non-shockable rhythms, called "PEA protocol" to remember the applications of the study (CA in Pulseless Electrical Activity, PEA) and the US scan sequence: Pulmonary scans to depict pneumothorax and pleural effusion and to differentiate wet or dry lung; Epigastric for pericardial effusion, left and right ventricular sides and motion, IVC filling; Abdominal and other scans for aortic aneurism and dissection, peritoneal effusion, bowel occlusion or perforation, deep venous thrombosis. The PEA protocol could be performed both during CA in PEA and during periarrest conditions.

CONCLUSIONS

Clinical US, using a well codified protocol, could effectively help to identify reversible causes in CA, even improving patients outcome.

Ultrasound detection of foreign body and gas contamination of a penetrating wound

We report a case in which ultrasonography (US) examination was used in the Emergency Department to reveal and diagnose gas contamination of a penetrating wound. Air microbubbles are extremely small and their typical distribution and movement are like those of "sparkling-wine microbubbles". US assessment of spontaneous disappearance of the air bubbles can distinguish a harmless traumatic nature of the wound from a life-threatening gas-producing bacterial infection.

Status epilepticus and neurodevelopmental outcome at 2 years of age in an extremely low birth weight infant

Neonatal status epilepticus (SE) is very rare and, to date, very little information exists on SE in preterm infants. Here, we report recurrent SE as a result of hypoxic-ischemic encephalopathy in an extremely low birth weight (ELBW) infant, who had favorable neurodevelopment at a corrected age of 2 years. This clinical observation seems to indicate that recurrent SE does not exclude normal long-term neurodevelopment, even in ELBW infants.

Scintigraphic evaluation of gastroesophageal reflux in newborns

OBJECTIVES

This study was carried out to verify whether during neonatal stage gastroesophageal scintigraphy, may be useful not only to diagnose gastroesophageal reflux (GER), but also to detect pulmonary aspiration, at times responsible for respiratory symptoms frequently associated with GER.

PATIENTS AND METHODS

Gastroesophageal scintigraphy was performed on 50 newborns admitted to NICU of Brindisi in the last two years who presented symptoms as cyanosis, apnoea, bradycardia, laringeal stridor, wheezing, not related to respiratory or cardiac problems, but suspected to be clinical suggestive symptoms of "pathological" GER. After administration of 99mTC mixed with the usual meal formula, we obtained a recording period of 60-90 minutes and a later recording at 4 and 24 hours to document radioactive material in lungs.

RESULTS

Scintigraphy showed GER in 40/50 cases and despite frequent observation of respiratory symptoms (39/40 cases) in these newborns never radiation in pulmonary fields.

CONCLUSIONS

Our results could indicate that scintigraphy, noninvasive and low in radiation, may be considered effective and reliable to diagnose GER in newborns. The absence of radiation in pulmonary fields could indicate that respiratory symptoms frequently associated with GER could depend on involuntary mechanism of vagal type and not on pulmonary aspiration.

Hemoperfusion and liver disease

After first adventurous attempts to apply perfusion techniques to the treatment of liver diseases, more extensive experiences have been acquired in the last twenty years, not only in acute hepatic failure but also in some chronic liver diseases (mainly in CAH:chronic active hepatitis, and in primary biliary cirrhosis) and in a severe complication of them, that is cryoglobulinemia. Some experiences on this field that are found in literature, using both plasma exchange and hemoperfusion, are reviewed and some personal data are reported: 15 patients with acute viral liver failure (survival rate: 33%) and 5 patients with a CAH-linked (3 viral and 2 autoimmune) cryoglobulinemia, in whom a good control of the disease parameters was obtained.

Fluid percussion barotrauma chamber: a new in vitro model for traumatic brain injury

Advances in the understanding of the pathophysiology of traumatic brain injury have implicated a number of cellular events as fundamental to the evolution of neurologic dysfunction in this process. Following the primary biomechanical insult, a highly complex series of biochemical changes occur, some of which are reversible. The development of fluid percussion injury as an in vivo model for traumatic brain injury has greatly improved our ability to study this disease. However, a comparable in vitro model of biomechanical injury which would enable investigators to study the response to injury in isolated cell types has not been described. We have developed a model of transient barotrauma in cell culture to examine the effects of this form of injury on cell metabolism. This model employs the same fluid percussion device commonly used in in vivo brain injury studies. The effect of this injury was evaluated in monolayers of human glial cells. Cell viability by trypan blue exclusion and the production of leukotrienes following increasing barotrauma was investigated. This model provided a reproducible method of subjecting cells in culture to forces similar to those currently used in animal experimental head injury.

[A therapeutic protocol with cefoperazone in bronchopneumopathy in mucoviscidosis]

Cystic fibrosis, a hereditary chronically evolving disease, is characterized by special predisposition to bronchial infections, especially by Pseudomonas strains. In the present open noncomparative study, the therapeutic efficacy of cefoperazone in respiratory infections by Pseudomonas aeruginosa in 25 children suffering from cystic fibrosis has been evaluated. Results were favorable, since both the specific symptoms of the infection and the general condition of the patients was markedly improved although the eradication of Pseudomonas was not achieved.

Leukotriene production by human glia

Elevated intracranial pressure and acute cerebrovascular changes following head injury remain the principle challenge in the management of traumatic brain injury. Recent work has demonstrated that leukotrienes can induce increases in blood brain barrier permeability and alter cerebrovascular dynamics. We investigated whether human astroglia in culture: 1. generate specific leukotrienes; 2. how they metabolize leukotrienes, and; 3. if astroglia generate leukotrienes in response to barotraumatic injury. Human astroglial cultures established from normal human brain obtained at surgery were exposed to either ionophore, exogenous 3H-LTC4, or barotraumatic injury. Supernatants were assayed for specific leukotrienes by one of three methods: HPLC, radioimmunoassay, or enzyme-immunoassay. Glial cells exposed to exogenous LTC4 metabolized nearly all of the LTC4 to LTD4 and LTE4 within 20 minutes. Glial cells stimulated with ionophore produced mostly LTC4 at five minutes after stimulation and LTD4 and LTE4 at fifteen minutes after stimulation. Glial cells subject to barotraumatic injury produced LTC4 in concentrations of 40-200 pg/ml 15 minutes after injury. These results demonstrate that human astroglial cells are capable of rapidly generating and degrading LTC4 and this capability of glial cells may play an important role in the pathophysiology of cerebrovascular changes following head injury.

The osmotic permeability of isolated calf pulmonary artery endothelial cells

Osmotic permeability coefficients, PF, for water in isolated calf pulmonary artery endothelial cells determined over the temperature range 41 to 20 degrees C are 311.10(-5) cm.s-1 at 37 degrees C and 159.10(-5) cm.s-1 at 20 degrees C. The value at 37 degrees C is close to that reported earlier for the diffusional permeability coefficient, PD. The PF/PD ratio is 1.0 at 37 degrees C. The PF values are within the range of values extrapolated for filtration permeability in pulmonary endothelium. The temperature dependence expressed as the activation energy is 7.2 kcal.mol-1. The product of hydraulic conductivity, Lp (or PF) and of viscosity changes in water is not constant from 37 to 20 degrees C. These results can be interpreted to indicate a similar pathway for water whether under diffusional or osmotic gradients.