The Vienna Genesis: An Example of Late Antique Purple Parchment.

The investigation and conservation of the Vienna Genesis, a Late Antique manuscript on purple parchment, included the study of parchment production and purple dyeing in the sixth century. The process of parchment making and of purple dyeing was recreated and compared with the Vienna Genesis and other manuscripts from the sixth and eighth centuries. Parchment made from the hides of young lambs and dyed with orchil resembled the folios of the Vienna Genesis. The results of material analysis and the study of parchment technology influenced decisions for the conservation and storage of the manuscript. Fragile areas of ink and parchment were stabilised with strips of adhesive coated Japanese tissue paper. The single folios are stored in folders of Japanese paper and museum matboard within a sink mat.

Correction: Babo et al. Characterization and Long-Term Stability of Historical PMMA: Impact of Additives and Acrylic Sheet Industrial Production Processes. Polymers 2020, 12, 2198.

The authors wish to make a change to the published paper [...].

Novel markers to early detect degradation on cellulose nitrate-based heritage at the submicrometer level using synchrotron UV-VIS multispectral luminescence.

Cellulose nitrate (CN) is an intrinsically unstable material that puts at risk the preservation of a great variety of objects in heritage collections, also posing threats to human health. For this reason, a detailed investigation of its degradation mechanisms is necessary to develop sustainable conservation strategies. To investigate novel probes of degradation, we implemented deep UV photoluminescence micro spectral-imaging, for the first time, to characterize a corpus of historical systems composed of cellulose nitrate. The analysis of cinematographic films and everyday objects dated from the nineteenth c./early twentieth c. (Perlov's collection), as well as of photo-aged CN and celluloid references allowed the identification of novel markers that correlate with different stages of CN degradation in artworks, providing insight into the role played by plasticizers, fillers, and other additives in stability. By comparison with photoaged references of CN and celluloid (70% CN and 30% camphor), it was possible to correlate camphor concentration with a higher rate of degradation of the cinematographic films. Furthermore, the present study investigates, at the sub-microscale, materials heterogeneity that correlates to the artworks' history, associating the different emission profiles of zinc oxide to specific color formulations used in the late nineteenth and early twentieth centuries.

Decision making based on hybrid modeling approach applied to cellulose acetate based historical films conservation.

Preserving culture heritage cellulose acetate-based historical films is a challenge due to the long-term instability of these complex materials and a lack of prediction models that can guide conservation strategies for each particular film. In this work, a cellulose acetate degradation model is proposed as the basis for the selection of appropriate strategies for storage and conservation for each specimen, considering its specific information. Due to the formulation complexity and diversity of cellulose acetate-based films produced over the decades, we hereby propose a hybrid modeling approach to describe the films degradation process. The problem is addressed by a hybrid model that uses as a backbone a first-principles based model to describe the degradation kinetics of the pure cellulose diacetate polymer. The mechanistic model was successfully adapted to fit experimental data from accelerated aging of plasticized films. The hybrid model considers then the specificity of each historical film via the development of two chemometric models. These models resource on gas release data, namely acetic acid, and descriptors of the films (manufacturing date, AD-strip value and film type) to assess the current polymer degradation state and estimate the increase in the degradation rate. These estimations are then conjugated with storage conditions (e.g., temperature and relative humidity, presence of adsorbent in the film's box) and used to feed the mechanistic model to provide the required time degradation simulations. The developed chemometric models provided predictions with accuracy more than 87%. We have found that the storage archive as well as the manufacturing company are not determining factors for conservation but rather the manufacturing date, off gas data as well as the film type. In summary, this hybrid modeling was able to develop a practical tool for conservators to assess films conservation state and to design storage and conservation policies that are best suited for each cultural heritage film.

Discoloration of Historical Plastic Objects: New Insight into the Degradation of ß-Naphthol Pigment Lakes.

Light is a determining factor in the discoloration of plastics, and photodegradation processes can affect the molecular structures of both the polymer and colorants. Limited studies focused on the discoloration of heritage plastics in conservation science. This work investigated the discoloration of red historical polyethylene (PE) objects colored with PR 48:2 and PR 53:1. High-density and low-density PE reference polymers, neat pigment powders, and historical samples were assessed before and after accelerated photoaging. The applied methodology provided insight into the individual light-susceptibility of polyethylenes, organic pigment lakes, and their combined effect in the photoaging of historical plastic formulations. After light exposure, both PE references and historical samples yellowed, PR53:1 faded, and PR 48:2 darkened; however, both organic pigments faded severely in the historical samples. This highlights the role played by the plastic binder likely facilitating the pigment photofading. Fourier transform infrared spectroscopy and mass spectrometry techniques-EGA-MS, PY-GC/MS, and TD-GC/MS-were successfully employed for characterizing the plastic formulations and degradation. The identification of phthalic compounds in both aged ß-naphthol powders opens new venues for studies on their degradation. This work's approach and analytical methods in studying the discoloration of historical plastics are novel, proving their efficacy, reliability, and potentiality.

Application of Infrared Reflectance Spectroscopy on Plastics in Cultural Heritage Collections: A Comparative Assessment of Two Portable Mid-Fourier Transform Infrared Reflection Devices.

Plastics have been increasingly used to create modern and contemporary art and design, and nowadays, museum collections hold numerous objects completely or partially made of plastics. However, the preservation of these materials is still a challenging task in heritage conservation, especially because some plastics show signs of degradation shortly after their production. In addition, different degradation mechanisms can often take place depending on the plastic composition and appropriate environmental and packaging conditions should be adopted. Therefore, methods for in situ and rapid characterization of plastic artifacts' composition are greatly needed to outline proper conservation strategies. Infrared (IR) spectroscopy, such as attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR), is a well-established method for polymeric material analysis. However, ATR FT-IR requires an intimate contact with the object, which makes its application less appropriate for the in situ investigation of fragile or brittle degraded plastic objects. Mid-FT-IR reflectance spectroscopy may represent a valid alternative as it allows in situ measurements with minimum or even no contact, and IR data can be acquired rapidly. On the other hand, spectral interpretation of reflectance spectra is usually difficult as IR bands may appear distorted with significant changes in band maximum, shape, and relative intensity, depending on the optical properties and surface texture of the material analyzed. Presently, mid-FT-IR reflection devices working in external reflection (ER FT-IR) and diffuse reflection infrared Fourier transform spectroscopy (DRIFTS) modes have been used in cultural heritage research studies. As the collected vibrational information depends on the optical layout of the measuring system, differences between ER FT-IR and DRIFT spectra are thus expected when the same polymer is analyzed. So far, ER FT-IR and DRIFT spectroscopy have been individually explored for the identification of plastic objects, but comparative studies between the application of two reflectance FT-IR modes have not been presented yet. In this work, the use of two portable FT-IR spectrometers equipped with ER FT-IR and DRIFTS modes were compared for plastics identification purposes for the first time. Both references of polymeric materials and historical plastic objects (from a Portuguese private collection) were studied and the differences between ER FT-IR and DRIFT spectra were discussed. The spectra features were examined considering the two different optical geometries and analytes' properties. This new insight can support a better understanding of both vibrational information acquired and practical aspects in the application of the ER FT-IR and DRIFTS in plastic analysis.

Pretreatment of Plastic Waste: Removal of Colorants from HDPE Using Biosolvents.

Plastics recycling remains a challenge due to the relatively low quality of the recycled material, since most of the developed recycling processes cannot deal with the additives present in the plastic matrix, so the recycled products end up in lower-grade applications. The application of volatile organic solvents for additives removal is the preferred choice. In this study, pretreatment of plastic packaging waste to remove additives using biosolvents was investigated. The plastic waste used was high-density polyethylene (HDPE) with blue and orange colorants (pigment and/or dye). The first step was to identify the type of colorants present in the HDPE, and we found that both plastics presented only one colorant that was actually a pigment. Then, limonene, a renewable solvent, was used to solubilize HDPE. After HDPE dissolution, a wide range of alcohols (mono-, di-, and tri-alcohols) was evaluated as antisolvents in order to selectively precipitate the polymer and maximize its purity. The use of limonene as solvent for plastic dissolution, in combination with poly-alcohols with an intermediate alkyl chain length and a large number of hydroxyl (OH) groups, was found to work best as an antisolvent (1,2,3-propanetriol and 1,2,4-butanetriol), leading to a removal of up to 94% and 100% of the blue and orange pigments, respectively. Finally, three cycles of extraction were carried out, proving the capability of the solvent and antisolvent to be recovered and reused, ensuring the economic viability and sustainability of the process. This pretreatment provides a secondary source of raw materials and revenue for the recycling process, which may lead to an increase in the quality of recycled polymers, contributing to the development of an economical and sustainable recycling process.

Characterization and Long-Term Stability of Historical PMMA: Impact of Additives and Acrylic Sheet Industrial Production Processes.

This work aims at understanding the influence of the production processes and materials in the properties and long term behavior of acrylic sheet, i.e., poly(methyl methacrylate) (PMMA), a material generally considered very stable in museum collections. A comparative study was conducted in samples from cast acrylic sheets produced in the early 2000s, from which manufacturing details were known, and samples provided by the artist Lourdes Castro from acrylic sheets she had bought in the 1960s. Transparent and red opaque cast acrylic samples, containing cadmium red pigment, were used. All samples were artificially aged in a solarbox with irradiation λ > 300 nm for a total period of 8000 h, and alterations were followed by a multi-analytical approach which included Raman, infrared (FTIR-ATR) and UV-Vis spectroscopies; gravimetry; size exclusion chromatography (SEC); thermogravimetry (TGA); micro-indentation; colorimetry; and optical microscopy. Not all cast PMMA sheets presented similar stabilities. We have concluded that the production processes (which may include the polymerization conditions, the organic additives and the origin of the monomer) play a more important role in the properties and long-term behavior of these acrylic sheets than the presence of cadmium red and/or the age of the material.

Prediction of acute kidney injury in cirrhotic patients: a new score combining renal, liver and inflammatory markers.

INTRODUCTION: Acute kidney injury (AKI) is common in hospitalized patients with cirrhosis and is associated with poor prognosis. A risk prediction score combining values easily measured at admission could be valuable to stratify patients for prevention, monitoring and early intervention, ultimately improving patient care and outcomes. The aim of this study was to develop a risk score for AKI in a cohort of cirrhotic patients. PATIENTS AND METHODS: We cross-examined the data from a retrospective analysis of 186 patients with cirrhosis admitted to the Gastroenterology and Hepatology Service of Centro Hospitalar Lisboa Norte from January 2003 to December 2005. AKI was defined as an increase in serum creatinine (SCr)≥0.3 mg/dL within 48 hours or a percentage increase in SCr≥50% from baseline. Neutrophil-to-lymphocyte ratio (NLR) was used as a marker for inflammation. A receiver operating characteristic (ROC) curve was produced to assess the discriminative ability of the variables. Cutoff values were defined as those with highest validity. The final AKI risk score model was assessed using the ROC curve. RESULTS: A total of 52 patients (28%) developed AKI. Higher baseline SCr (p<0.001), more severe liver disease as evaluated by the modified Model of End-stage Liver Disease (MELD)-Na score (p<0.001) and higher NLR (p=0.028) were independently associated with AKI. The area under the ROC (AUROC) curve for the prediction of AKI was 0.791 (95% CI 0.726-0.847) for SCr, 0.771 (95% CI 0.704-0.829) for modified MELD-Na and 0.757 (95% CI 0.689-0.817) for NLR. Cutoff values with the highest validity for predicting AKI were determined and defined as 0.9 for the SCr, 21.7 for the modified MELD-Na and 6 for the NLR. The risk score was created allowing 3 points if the SCr is higher than 0.9, 1 point if the modified MELD-Na is higher than 21.7 and 1 point if the NLR is higher than 6. The AUROC curve of the risk prediction score for AKI was 0.861. A risk score of ≥2 points predicts AKI in cirrhotic patients with a sensitivity of 88.5% and specificity of 72.4%. CONCLUSION: A new score combining SCr, MELD-Na and NLR demonstrated a strong discriminative ability to predict AKI in cirrhotic patients.

Organic dyes in illuminated manuscripts: a unique cultural and historic record.

In this study, we successfully addressed the challenges posed by the identification of dyes in medieval illuminations. Brazilwood pigment lakes and orcein purple colours were unequivocally identified in illuminated manuscripts dated by art historians to be from the thirteenth to the fifteenth centuries and in the Fernão Vaz Dourado Atlas (sixteenth century). All three works were on a parchment support. This was possible by combining Raman microscopy and surface-enhanced Raman spectroscopy with microspectrofluorimetry. To the best of our knowledge, this is the first time that brazilein, the main chromophore in brazilwood lake pigments, has been unequivocally identified by surface-enhanced Raman spectroscopy in an illuminated work (the Dourado Atlas). Complementing this identification, through microspectrofluorimetry and micro-Fourier transform infrared spectroscopy, it was possible to propose a complete paint formulation by comparison with our database of references; the dark pink hues, in the three case studies, were produced by combining brazilwood pigment lakes and gypsum in a protein- and gum arabic-based tempera. Orcein purple, also known as orchil dye, has been previously identified in medieval manuscripts, dated from the sixth to the ninth centuries. Our findings in fourteenth-sixteenth century manuscripts confirm the hypothesis that this dye was lost during the High Middle Ages, to be later rediscovered.This article is part of the themed issue 'Raman spectroscopy in art and archaeology'.

Acute kidney injury, long-term renal function and mortality in patients undergoing major abdominal surgery: a cohort analysis.

BACKGROUND: Acute kidney injury (AKI) is frequent during hospitalization and may contribute to adverse consequences. We aimed to evaluate long-term adverse renal function and mortality after postoperative AKI in a cohort of patients undergoing major abdominal surgery. METHODS: We performed a retrospective analysis of adult patients who underwent major non-vascular abdominal surgery between January 2010 and February 2011 at the Department of Surgery II of Hospital de Santa Maria-Centro Hospitalar Lisboa Norte, Portugal. Exclusion criteria were as follows: chronic kidney disease on renal replacement therapy, undergoing renal replacement therapy the week before surgery, death before discharge and loss to follow-up through January 2014. Patients were categorized according to the development of postoperative AKI in the first 48 h after surgery using the Kidney Disease: Improving Global Outcomes classification. AKI was defined by an increase in absolute serum creatinine (SCr) ≥0.3 mg/dL or by a percentage increase in SCr ≥50% and/or by a decrease in urine output to <0.5 mL/kg/h for >6 h. Adverse renal outcomes (need for long-term dialysis and/or a 25% decrease in estimated glomerular filtration rate after hospital discharge) and mortality after discharge were evaluated. Cumulative mortality was analysed with the Kaplan-Meier method and log-rank test and outcome predictive factors with the Cox regression. Significance was set at P < 0.05. RESULTS: Of 390 selected patients, 72 (18.5%) developed postoperative AKI. The median follow-up was 38 months. Adverse renal outcomes and death after hospital discharge were more frequent among AKI patients (47.2 versus 22.0%, P < 0.0001; and 47.2 versus 20.5%, P < 0.0001, respectively). The 4 year cumulative probability of death was 44.4% for AKI patients, while it was 19.8% for patients with no AKI (log-rank test, P < 0.0001). In multivariate analysis, AKI was a risk factor for adverse renal outcomes (adjusted hazard ratio 1.6, P = 0.046) and mortality (adjusted hazard ratio 1.4, P = 0.043). CONCLUSIONS: AKI after major abdominal surgery was independently associated with the risk of long-term need for dialysis and/or renal function decline and with the risk of death after hospital discharge.

Acute kidney injury after major abdominal surgery: a retrospective cohort analysis.

Background. We analyzed the incidence, risk factors, and prognosis of acute kidney injury (AKI) in a cohort of patients undergoing major abdominal surgery. Methods. A total of 450 patients were retrospectively studied. AKI was defined by an increase in serum creatinine (SCr) ≥ 0.3 mg/dl or by an increase in SCr ≥ 50% and/or by a decrease in urine output to 0.5 ml/kg/hour for 6 hours, in the first 48 hours after surgery. Logistic regression method was used to determine predictors of AKI and in-hospital mortality. A two-tailed P value <0.05 was considered significant. Results. One hundred one patients (22.4%) had postoperative AKI. Age (adjusted odds ratio (OR) 1.02, 95% confidence interval (CI) 1.01-1.05), nonrenal Revised Cardiac Risk Index score (adjusted OR 1.9, 95% CI 1.3-3.1, P = 0.003), intraoperative erythrocytes transfusions (adjusted OR 2.2, 95% CI 1.4-3.5, P <.0001), and nonrenal Simplified Acute Physiology Score II (adjusted OR 1.03, 95% CI 1.01-1.06, P = 0.0191) were associated with postoperative AKI. AKI was associated with increased in-hospital mortality (20.8% versus 2.3%, P <.0001; unadjusted OR 11.2, 95% CI 4.8-26.2, P <.0001; adjusted OR 3.7, 95% CI 1.2-11.7, P = 0.024). Conclusion. AKI was common in patients undergoing major abdominal surgery and was associated with in-hospital mortality.

A spectroscopic study of Brazilwood paints in medieval books of hours.

In this work, microspectrofluorimetry was for the first time applied to the identification of the red organic lakes that are characteristic of the lavish illuminations found in 15(th) century books of hours. Microspectrofluorimetry identified those red paints, ranging from opaque pink to dark red glazes, as brazilwood lakes. An unequivocal characterization was achieved by comparison with reference paints produced following recipes from the medieval treatise The Book on How to Make Colours, and was further confirmed by fiber optic reflectance spectroscopy (FORS). For these treasured cultural objects, microspectrofluorimetry and FORS proved to be the only techniques that could identify, in situ or in microsamples, the chromophore responsible for the pinkish hues: a brazilein-Al(3+) complex. Additionally, a multi-analytical approach provided a full characterization of the color paints, including pigments, additives, and binders. Microspectroscopic techniques, based on infrared and X-ray radiation, enabled us to disclose the full palette of these medieval manuscripts, including the elusive greens, for which, besides malachite, basic copper sulfates were found; Raman microscopy suggested a mixture of brochantite and langite. Infrared analysis proved invaluable for a full characterization of the additives that were applied as fillers or whites (chalk, gypsum, and white lead) as well as the proteinaceous and polysaccharide binders that were found pure or in mixture.

Long-term risk of mortality for acute kidney injury in HIV-infected patients: a cohort analysis.

BACKGROUND: Acute kidney injury (AKI) is common in hospitalized human immunodeficiency virus (HIV)-infected patients and is associated with hospital mortality. We aimed to evaluate the impact of AKI on long-term mortality of hospitalized HIV-infected patients. METHODS: Retrospective analysis of a cohort of 433 hospitalized HIV-infected patients who were discharged alive from the hospital. AKI was defined according to 'Risk Injury Failure Loss of kidney function End-stage kidney disease' creatinine criteria, as an increase of baseline serum creatinine (SCr) X 1.5 or in patients with baseline SCr > 4 mg/dL if there was an acute rise in SCr of at least 0.5 mg/dL. Cumulative mortality curves were determined by the Kaplan-Meier method, and log-rank test was employed to analyze statistically significant differences between curves. Cox regression method was used to determine independent predictors of mortality. Risk factors were assessed with univariate analysis, and variables that were statistically significant (P < 0.05) in the univariate analysis were included in the multivariate analysis. RESULTS: Sixty-four patients (14.8%) had AKI. Median follow-up was 37 months. At follow-up 81 patients (18.7%) died. At 1, 2 and 5 years of follow-up, the cumulative probability of death of patients with AKI was 21.2, 25 and 31.3%, respectively, as compared with 10, 13.3 and 16.5% in patients without AKI (log-rank, P = 0.011). In multivariate analysis AKI was associated with increased mortality (adjusted HR 1.7, 95% CI 1.1-3; P = 0.049). CONCLUSIONS: AKI was independently associated with long-term mortality of hospitalized HIV-infected patients.

Ochres and earths: matrix and chromophores characterization of 19th and 20th century artist materials.

The present paper describes the main results obtained from the characterization of a wide range of natural and synthetic ochre samples used in Portugal from the 19th to the 20th century, including powder and oil painting samples. The powder ochre samples came from several commercial distributors and from the collection of Joaquim Rodrigo (1912-1997), a leading Portuguese artist, particularly active during the sixties and seventies. The micro-samples of oil painting tubes came from the Museu Nacional de Arte Contemporânea-Museu do Chiado (National Museum of Contemporary Art-Chiado Museum) in Lisbon and were used by Columbano Bordalo Pinheiro (1857-1929), one of the most prominent naturalist Portuguese painters. These tubes were produced by the main 19th century colourmen: Winsor & Newton, Morin et Janet, Maison Merlin, and Lefranc. The samples have been studied using µ-Fourier Transform Infrared Spectroscopy (µ-FTIR), Raman microscopy, µ-Energy Dispersive X-ray fluorescence (µ-EDXRF), and X-ray diffraction (XRD). The analyzed ochres were found to be a mixture of several components: iron oxides and hydroxides in matrixes with kaolinite, gypsum and chalk. The results obtained allowed to identify and characterize the ochres according to their matrix and chromophores. The main chromophores where identified by Raman microscopy as being hematite, goethite and magnetite. The infrared analysis of the ochre samples allowed to divide them into groups, according to the composition of the matrix. It was possible to separate ochres containing kaolinite matrix and/or sulfate matrix from ochres where only iron oxides and/or hydroxides were detected. µ-EDXRF and Raman were the best techniques to identify umber, since the presence of elements such as manganese is characteristic of these pigments. µ-EDXRF also revealed the presence of significant amounts of arsenic in all Sienna tube paints.

Seroepidemiological survey of transmissible infectious diseases in a portuguese prison establishment.

A cross-sectional study was conducted in 151 (71.6%) of 211 male inmates of a regional Portuguese prison in order to establish the seroprevalence for viral hepatitis (HAV, HBV, HCV), human immunodeficiency virus (HIV), syphilis and herpes simplex virus (HSV-1 and HSV-2) and to analyze some psychosocial and criminal characteristics. Mean age was 34 years. Anti-HAV was positive in 69.5% (n = 105) and in 34.4% (n = 52) for anti-HCV. One (0.7%) person had HBsAg and 29 (19.2%) had laboratory markers of past HBV infection. Non-immune inmates for HBV were 40.4% (n = 61). Syphilis was diagnosed in 6.0% (n = 9). The rate of HIV infection was 6.6% (n = 10; all HIV-1). The seropositivity of HSV-2 was 19.9% (n = 30) and of HSV-1 was 82.1% (n = 124). Alcohol dependence was reported by 26.5% (n = 40). Excluding tobacco and prescription medication, 73.5% (n = 111) reported drug use in prison. The most commonly used drugs were: cannabis (100%; n = 111) followed by heroin (56.7%; n = 63). Anti-HCV rate was noteworthy. The HIV infection rate (6.6%) in this regional prison is at least 13 to 22 times greater than in general population. As the inmate return to the community increases the risk of disease exposure for the general population, early detection and counseling is urgently needed for prisoners.

Seroepidemiological survey of transmissible infectious diseases in a portuguese prison establishment

A cross-sectional study was conducted in 151 (71.6 percent) of 211 male inmates of a regional Portuguese prison in order to establish the seroprevalence for viral hepatitis (HAV, HBV, HCV), human immunodeficiency virus (HIV), syphilis and herpes simplex virus (HSV-1 and HSV-2) and to analyze some psychosocial and criminal characteristics. Mean age was 34 years. Anti-HAV was positive in 69.5 percent (n = 105) and in 34.4 percent (n = 52) for anti-HCV. One (0.7 percent) person had HBsAg and 29 (19.2 percent) had laboratory markers of past HBV infection. Non-immune inmates for HBV were 40.4 percent (n = 61). Syphilis was diagnosed in 6.0 percent (n = 9). The rate of HIV infection was 6.6 percent (n = 10; all HIV-1). The seropositivity of HSV-2 was 19.9 percent (n = 30) and of HSV-1 was 82.1 percent (n = 124). Alcohol dependence was reported by 26.5 percent (n = 40). Excluding tobacco and prescription medication, 73.5 percent (n = 111) reported drug use in prison. The most commonly used drugs were: cannabis (100 percent; n = 111) followed by heroin (56.7 percent; n = 63). Anti-HCV rate was noteworthy. The HIV infection rate (6.6 percent) in this regional prison is at least 13 to 22 times greater than in general population. As the inmate return to the community increases the risk of disease exposure for the general population, early detection and counseling is urgently needed for prisoners.

Acute kidney injury in hospitalized HIV-infected patients: a cohort analysis.

BACKGROUND: Acute kidney injury (AKI) in hospitalized human immunodeficiency virus (HIV)-infected patients in the highly active antiretroviral therapy (HAART) era has not been extensively addressed. The aim of the present study was to analyze the incidence, etiology, risk factors and the impact of AKI on in-hospital mortality in this population. METHODS: A total of 489 HIV-infected patients hospitalized in the Department of Infectious Diseases of the Hospital de Santa Maria (Lisbon, Portugal) between January 2005 and December 2007 were retrospectively studied. AKI was defined by 'Risk Injury Failure Loss of kidney function End-stage kidney disease'(RIFLE) criteria based on serum creatinine. Comparisons between patients with and without AKI were performed using the Student's t-test or the χ2 test. Logistic regression method was used to determine predictors of AKI and in-hospital mortality. A two-tailed P-value <0.05 was considered significant. RESULTS: Eighty-eight patients (18%) had AKI within the hospitalization period. The most common etiologies of AKI were sepsis (59%), nephrotoxic drug administration (37.5%), volume depletion (21.6%) and radiocontrast use (20.5%). Preexisting hypertension [adjusted odds ratio (OR) 2.4, 95% confidence interval (CI) 1.04-5.6, P = 0.04], acquired immunodeficiency syndrome (adjusted OR 2.7, 95% CI 1.2-6, P = 0.02), sepsis (adjusted OR 23, 95% CI 11-45.3, P < 0.001) and nephrotoxic drug administration (adjusted OR 2.8, 95% CI 1.4-5.8, P = 0.004) were risk factors of AKI. Patients with AKI had higher in-hospital mortality than patients without AKI (27.3 versus 8%, P < 0.001). In multivariate analysis, AKI was a risk factor of in-hospital mortality (adjusted OR 2.7, 95% CI 1.3-5.6, P = 0.008). CONCLUSION: AKI occurred in 18% of hospitalized HIV-infected patients and it was independently associated with increased in-hospital mortality.