Nearly perfect near-infrared luminescence efficiency of Si nanocrystals: A comprehensive quantum yield study employing the Purcell effect.

Thin layers of silicon nanocrystals (SiNC) in oxide matrix with optimized parameters are fabricated by the plasma-enhanced chemical vapor deposition. These materials with SiNC sizes of about 4.5 nm and the SiO2 barrier thickness of 3 nm reveal external quantum yield (QY) close to 50% which is near to the best chemically synthetized colloidal SiNC. Internal QY is determined using the Purcell effect, i.e. modifying radiative decay rate by the proximity of a high index medium in a special wedge-shape sample. For the first time we performed these experiments at variable temperatures. The complete optical characterization and knowledge of both internal and external QY allow to estimate the spectral distribution of the dark and bright NC populations within the SiNC ensemble. We show that SiNCs emitting at around 1.2-1.3 eV are mostly bright with internal QY reaching 80% at room temperature and being reduced by thermally activated non-radiative processes (below 100 K internal QY approaches 100%). The mechanisms of non-radiative decay are discussed based on their temperature dependence.

Structural Modeling of γ-Secretase Aß n Complex Formation and Substrate Processing.

The intramembrane aspartyl protease γ-secretase (GSEC) cleaves single-span transmembrane helices including the C-terminal fragment of the amyloid precursor protein (APP). This substrate is initially cleaved at the ϵ-site followed by successive processing (trimming) events mostly in steps of three amino acids. GSEC is responsible for the formation of N-terminal APP amyloid-ß (Aß) peptides of different length (e.g., Aß42) that can form aggregates involved in Alzheimer's disease pathogenesis. The molecular mechanism of GSEC-APP substrate recognition is key for understanding how different peptide products are formed and could help in designing APP-selective modulators. Based on the known structure of apo GSEC and the APP-C99 fragment we have generated putative structural models of the initial binding in three different possible modes using extensive molecular dynamics (MD) simulations. The binding mode with the substrate helix located in a cleft between the transmembrane helices 2 and 3 of the presenilin subunit was identified as a most likely binding mode. Based on this arrangement, the processing steps were investigated using restraint MD simulations to pull the scissile bond (for each processing step) into a transition like (cleavable) state. This allowed us to analyze in detail the motions and energetic contributions of participating residues. The structural model agrees qualitatively well with the influence of many mutations in GSEC and C99. It also explains the effects of inhibitors, cross-linking, as well as spectroscopic data on GSEC substrate binding and can serve as working model for the future planning of structural and biochemical studies.

Interplay of bimolecular and Auger recombination in photoexcited carrier dynamics in silicon nanocrystal/silicon dioxide superlattices.

We report results of investigating carrier recombination in silicon nanocrystal/silicon dioxide superlattices. The superlattices prepared by nitrogen-free plasma enhanced chemical vapour deposition contained layers of silicon nanocrystals. Femtosecond transient transmission optical spectroscopy was used to monitor carrier mechanisms in the samples. The three-particle Auger recombination was observed in accord with previous reports. However, under high pump intensities (high photoexcited carrier densities) the bimolecular process dominated the recombination. Detailed analysis of measured data and fitting procedure made it possible to follow and quantify the interplay between the two recombination processes. The bimolecular recombination was interpreted in terms of the trap-assisted Auger recombination.

Structural parameters effect on the electrical and electroluminescence properties of silicon nanocrystals/SiO2 superlattices.

The effect of the oxide barrier thickness (tSiO2) reduction and the Si excess ([Si]exc) increase on the electrical and electroluminescence (EL) properties of Si-rich oxynitride (SRON)/SiO2 superlattices (SLs) is investigated. The active layers of the metal-oxide-semiconductor devices were fabricated by alternated deposition of SRON and SiO2 layers on top of a Si substrate. The precipitation of the Si excess and thus formation of Si nanocrystals (NCs) within the SRON layers was achieved after an annealing treatment at 1150 °C. A structural characterization revealed a high crystalline quality of the SLs for all devices, and the evaluated NC crystalline size is in agreement with a good deposition and annealing control. We found a dramatic conductivity enhancement when the Si content is increased or the SiO2 barrier thickness is decreased, due to a larger interaction of the carrier wavefunctions from adjacent layers. EL recombination dynamics were studied, revealing radiative recombination decay times of the order of tens of microseconds. Lower lifetimes were found at higher [Si]exc, attributed to exciton confinement delocalization, whereas intermediate barrier thicknesses present the slowest decay. The electrical-to-light conversion efficiency increases monotonously at thicker barriers and smaller Si contents. We ascribe these effects mainly to free carriers, which enhance carrier transport through the SLs while strongly quenching light emission. Finally, the combination of the different results led us to conclude that tSiO2 âˆ¼ 2 nm and [Si]exc from 12 to 15 at% are the ideal structure parameters for a balanced electro-optical response of Si NC-based SLs.

Clinical and pathological nodal staging score for urothelial carcinoma of the bladder: an external validation.

PURPOSE: Radical cystectomy (RC) and pelvic lymph node dissection (LND) are standard treatments for muscle-invasive urothelial carcinoma of the bladder. Lymph node staging is a prerequisite for clinical decision-making regarding adjuvant chemotherapy and follow-up regimens. Recently, the clinical and pathological nodal staging scores (cNSS and pNSS) were developed. Prior to RC, cNSS determines the minimum number of lymph nodes required to be dissected; pNSS quantifies the accuracy of negative nodal staging based on pT stage and dissected LNs. cNSS and pNSS have not been externally validated, and their relevance for prediction of cancer-specific mortality (CSM) has not been assessed. METHODS: In this retrospective study of 2,483 RC patients from eight German centers, we externally validated cNSS and pNSS and determined their prediction of CSM. All patients underwent RC and LND. Median follow-up was 44 months. cNSS and pNSS sensitivities were evaluated using the original beta-binominal models. Adjusted proportional hazards models were calculated for pN0 patients to assess the predictive value of cNSS and pNSS for CSM. RESULTS: cNSS and pNSS both pass external validation. Adjusted for other clinical parameters, cNSS can predict outcome after RC. pNSS has no independent impact on prediction of CSM. The retrospective design is the major limitation of the study. CONCLUSIONS: In the present external validation, we confirm the validity of both cNSS and pNSS. cNSS is an independent predictor of CSM, thus rendering it useful as a tool for planning the extent of LND.

Prediction of outcome in patients with urothelial carcinoma of the bladder following radical cystectomy using artificial neural networks.

AIM: The outcome of patients with urothelial carcinoma of the bladder (UCB) after radical cystectomy (RC) shows remarkable variability. We evaluated the ability of artificial neural networks (ANN) to perform risk stratification in UCB patients based on common parameters available at the time of RC. METHODS: Data from 2111 UCB patients that underwent RC in eight centers were analysed; the median follow-up was 30 months (IQR: 12-60). Age, gender, tumour stage and grade (TURB/RC), carcinoma in situ (TURB/RC), lymph node status, and lymphovascular invasion were used as input data for the ANN. Endpoints were tumour recurrence, cancer-specific mortality (CSM) and all-cause death (ACD). Additionally, the predictive accuracies (PA) of the ANNs were compared with the PA of Cox proportional hazards regression models. RESULTS: The recurrence-, CSM-, and ACD- rates after 5 years were 36%, 33%, and 46%, respectively. The best ANN had 74%, 76% and 69% accuracy for tumour recurrence, CSM and ACD, respectively. Lymph node status was one of the most important factors for the network's decision. The PA of the ANNs for recurrence, CSM and ACD were improved by 1.6% (p = 0.247), 4.7% (p < 0.001) and 3.5% (p = 0.007), respectively, in comparison to the Cox models. CONCLUSIONS: ANN predicted tumour recurrence, CSM, and ACD in UCB patients after RC with reasonable accuracy. In this study, ANN significantly outperformed the Cox models regarding prediction of CSM and ACD using the same patients and variables. ANNs are a promising approach for individual risk stratification and may optimize individual treatment planning.

External validation of disease-free survival at 2 or 3 years as a surrogate and new primary endpoint for patients undergoing radical cystectomy for urothelial carcinoma of the bladder.

PURPOSE: To perform the first external validation of a recently identified association between disease-free survival at two years (DFS2) or three years (DFS3) and overall survival at five years (OS5) in patients after radical cystectomy (RC) for muscle-invasive urothelial carcinoma of the bladder (UCB). METHODS AND METHODS: Records of 2483 patients who underwent RC for UCB at eight European centers between 1989 and 2008 were reviewed. The cohort included 1738 patients with pT2-4a tumors and negative soft tissue surgical margins (STSM) according to the selection criteria of the previous study (study group (SG)). In addition, 745 patients with positive STSM or other tumor stages (pT0-T1, pT4b) that were excluded from the previous study (excluded patient group (EPG)) were evaluated. Kappa statistic was used to measure the agreement between DFS2 or DFS3 and OS5. RESULTS: The overall agreement between DFS2 and OS5 was 86.5% (EPG: 88.7%) and 90.1% (EPG: 92.1%) between DFS3 and OS5. The kappa values for comparison of DFS2 or DFS3 with OS5 were 0.73 (SE: 0.016) and 0.80 (SE: 0.014) respectively for the SG, and 0.67 (SE: 0.033) and 0.78 (SE: 0.027) for the EPG (all p-values <0.001). CONCLUSIONS: We externally validated a correlation between DFS2 or DFS3 and OS5 for patients with pT2-4a UCB with negative STSM that underwent RC. Furthermore, this correlation was found in patients with other tumor stages regardless of STSM status. These findings indicate DFS2 and DFS3 as valid surrogate markers for survival outcome with RC.

[Validation of pre-cystectomy nomograms for the prediction of locally advanced urothelial bladder cancer in a multicentre study: are we able to adequately predict locally advanced tumour stages before surgery?]. / Validierung von Präzystektomienomogrammen zur Vorhersage lokal fortgeschrittener Harnblasenkarzinome in einer multizentrischen Studie : Können wir lokal fortgeschrittene Tumorstadien präoperativ ausreichend sicher vorhersagen?

OBJECTIVE: Pre-cystectomy nomograms with a high predictive ability for locally advanced urothelial carcinomas of the bladder would enhance individual treatment tailoring and patient counselling. To date, there are two currently not externally validated nomograms for prediction of the tumour stages pT3-4 or lymph node involvement. MATERIALS AND METHODS: Data from a German multicentre cystectomy series comprising 2,477 patients with urothelial carcinoma of the bladder were applied for the validation of two US nomograms, which were originally based on the data of 726 patients (nomogram 1: prediction of pT3-4 tumours, nomogram 2: prediction of lymph node involvement). Multivariate regression models assessed the value of clinical parameters integrated in both nomograms, i.e. age, gender, cT stage, TURB grade and associated Tis. Discriminative abilities of both nomograms were assessed by ROC analyses; calibration facilitated a comparison of the predicted probability and the actual incidence of locally advanced tumour stages. RESULTS: Of the patients, 44.5 and 25.8% demonstrated tumour stages pT3-4 and pN+, respectively. If only one case of a previously not known locally advanced carcinoma (pT3-4 and/or pN+) is considered as a staging error, the rate of understaging was 48.9% (n=1211). The predictive accuracies of the validated nomograms were 67.5 and 54.5%, respectively. The mean probabilities of pT3-4 tumours and lymph node involvement predicted by application of these nomograms were 36.7% (actual frequency 44.5%) and 20.2% (actual frequency 25.8%), respectively. Both nomograms underestimated the real incidence of locally advanced tumours. CONCLUSIONS: The present study demonstrates that prediction of locally advanced urothelial carcinomas of the bladder by both validated nomograms is not conferrable to patients of the present German cystectomy series. Hence, there is still a need for statistical models with enhanced predictive accuracy.

[Influence of older age on survival after radical cystectomy due to urothelial carcinoma of the bladder: survival analysis of a German multi-centre study after curative treatment of urothelial carcinoma of the bladder]. / Einfluss des Alters auf das karzinomspezifische Überleben nach radikaler Zystektomie : Überlebensanalyse aus einer deutschen Multicenterstudie nach kurativer Therapie eines Urothelkarzinoms der Harnblase.

BACKGROUND: The therapeutic gold standard of muscle-invasive tumour stages is radical cystectomy (RC), but there are still conflicting reports about associated morbidity and mortality and the oncologic benefit of RC in elderly patients. The aim of the present study was the comparison of overall (OS) and cancer-specific survival (CSS) in patients <75 and >75 years of age (median follow-up was 42 months). PATIENTS AND METHODS: Clinical and histopathological data of 2,483 patients with urothelial carcinoma and consecutive RC were collated. The study group was dichotomized by the age of 75 years at RC. Statistical analyses comprising an assessment of postoperative mortality within 90 days, OS and CSS were assessed. Multivariate logistic regression and survival analyses were performed. RESULTS: The 402 patients (16.2%) with an age of ≥75 years at RC showed a significantly higher local tumour stage (pT3/4 and/or pN+) (58 vs 51%; p=0.01), higher tumour grade (73 vs 65%; p=0.003) and higher rates of upstaging in the RC specimen (55 vs 48%; p=0.032). Elderly patients received significantly less often adjuvant chemotherapy (8 vs 15%; p<0.001). The 90-day mortality was significantly higher in patients ≥75 years (6.2 vs 3.7%; p=0.026). When adjusted for different variables (gender, tumour stage, adjuvant chemotherapy, time period of RC), only in male patients and locally advanced tumour stages was an association with 90-day mortality noticed. The multivariate analysis showed that patients ≥75 years of age have a significantly worse OS (HR=1.42; p<0.001) and CSS (HR=1.27; p=0.018). CONCLUSIONS: An age of ≥75 years at RC is associated with a worse outcome. Prospective analyses including an assessment of the role of comorbidity and possibly age-dependent tumour biology are warranted.

[Patients with bladder cancer in clinical stage T2 : survival benefit of downstaging in comparison to patients with confirmed muscle invasion in cystectomy specimens]. / Harnblasenkarzinompatienten im klinischen Tumorstadium T2 : Überlebensvorteil eines Downstaging gegenüber Patienten mit bestätigter Muskelinvasion im Zystektomiepräparat.

BACKGROUND: Few and partially contradictory data are available regarding the prognostic signature of downstaging of muscle-invasive clinical tumour stages in patients treated with radical cystectomy. MATERIALS AND METHODS: Clinicopathological parameters of 1,643 patients (study group, SG) treated with radical cystectomy due to muscle-invasive urothelial bladder cancer were summarized in a multi-institutional database. Patients of the SG fulfilled the following conditions: clinical tumour stage T2 N0 M0 and no administration of neoadjuvant radiation or chemotherapy. Cancer-specific survival (CSS) rates were calculated referring to pathological tumour stages in cystectomy specimens (pT2) (mean follow-up: 51 months). Furthermore, a multivariable model integrating clinical information was developed in order to predict the probability of downstaging. RESULTS: A total of 173 patients (10.5%) of the SG presented with downstaging in pathological tumour stages (pT0: 4.8%, pTa: 0.4%, pTis: 1.3%, pT1: 4.1%); 12 of these patients had positive lymph nodes (7%, in comparison with 21% pN+ of pT2 tumours and 43% of >pT2 tumours). Patients with tumour stages pT2 had CSS rates after 5 years of 89, 69 and 46%, respectively (p<0.001). In a multivariable Cox model the presence of pathological downstaging resulted in a significant reduction of cancer-specific mortality (HR 0.30; 95% CI 0.18-0.50). By logistic regression analysis the date of TURB (benefit for more recent operations) was identified as the only independent predictor for downstaging of muscle-invasive clinical tumour stages. Age, gender, grading and associated Tis in the TURB did not reveal any significant influence. CONCLUSION: Patients with muscle-invasive clinical tumour stages and downstaging in cystectomy specimens represent a subgroup with significantly enhanced CSS rates. Further trials that integrate the parameters tumour size, stages cT2a vs cT2b and focality are required in order to define the independent prognostic signature of downstaging of tumour stages more precisely.

[F(18)]-fluoroethylcholine combined in-line PET-CT scan for detection of lymph-node metastasis in high risk prostate cancer patients prior to radical prostatectomy: Preliminary results from a prospective histology-based study.

PURPOSE: To evaluate the diagnostic potential of PET/CT using ([F(18)]fluorethylcholine (FEC) for lymph node (LN) staging in high risk prostate cancer (PCa) patients prior to radical prostatectomy (RP). PATIENTS AND METHODS: Twenty patients with localised PCa and > or =20% LN risk according to a published nomogram were prospectively enrolled. FEC PET/CT was done minimum 14 d after prostate biopsy. Afterwards, open RP and extended pelvic LN dissection (ePLND) were performed. Clinical stage, Prostate Specific Antigen (PSA) and biopsy Gleason Grading were assessed and histopathological evaluation of the RP-specimens and dissected LN has been performed. The results from PET/CT were compared with LN metastasis according to their anatomical site. RESULTS: Overall, 285 LN have been removed with a mean number of 15 nodes per patient (7-26). Of the 20 patients, 9 men were LN positive (45%), which corresponds to 31 positive LN with a mean size of 7 mm (0.8-12 mm). Dissection of the obturator fossa, external iliac artery/vein and internal iliac artery/vein revealed 36%, 48% and 16% of positive LN, respectively. FEC PET/CT did not detect one single positive LN, thus was false-negative in 31 metastasis and true negative in 254 LN. CONCLUSION: Based on our results which confirmed experience from the previous studies, FEC PET/CT scan did not prove to be useful for LN staging in localised PCa prior to treatment and should thus not be applied if clinically occult metastatic disease is suspected.

Classification and control of the origin of photoluminescence from Si nanocrystals.

Silicon dominates the electronics industry, but its poor optical properties mean that III-V compound semiconductors are preferred for photonics applications. Photoluminescence at visible wavelengths was observed from porous Si at room temperature in 1990, but the origin of these photons (do they arise from highly localized defect states or quantum confinement effects?) has been the subject of intense debate ever since. Attention has subsequently shifted from porous Si to Si nanocrystals, but the same fundamental question about the origin of the photoluminescence has remained. Here we show, based on measurements in high magnetic fields, that defects are the dominant source of light from Si nanocrystals. Moreover, we show that it is possible to control the origin of the photoluminescence in a single sample: passivation with hydrogen removes the defects, resulting in photoluminescence from quantum-confined states, but subsequent ultraviolet illumination reintroduces the defects, making them the origin of the light again.

The interface of protein-protein complexes: analysis of contacts and prediction of interactions.

Specific protein-protein interactions are essential for cellular functions. Experimentally determined three-dimensional structures of protein-protein complexes offer the possibility to characterize binding interfaces in terms of size, shape and packing density. Comparison with crystal-packing interfaces representing nonspecific protein-protein contacts gives insight into how specific binding differs from nonspecific low-affinity binding. An overview is given on empirical structural rules for specific protein-protein recognition derived from known complex structures. Although single parameters such as interface size, shape or surface complementary show clear trends for different interface types, each parameter alone is insufficient to fully distinguish between specific versus crystal-packing contacts. A combination of interface parameters is, however, well suited to characterize a specific interface. This knowledge provides us with the essential ingredients that make up a specific protein recognition site. It is also of great value for the prediction of protein binding sites and for the evaluation of predicted complex structures.

Enhanced surface-excitonic emission in ZnO/Al(2)O(3) core-shell nanowires.

We report the influence of an Al(2)O(3) shell on the photoluminescence emission of ZnO nanowires. At room temperature, the spectrum of the core-shell nanowires shows a strong reduction of the relative intensity of the green defect emission with respect to the near-band-edge emission. At 5 K an increase of the relative intensity of the surface exciton band with respect to the donor-bound exciton emission is observed. Annealing the core-shell nanowires at 500 °C does not increase the green defect luminescence at 5 K. We propose a model explaining the spectral changes.

Comparative safety and efficacy of two high dose regimens of oral paracetamol in healthy adults undergoing third molar surgery under local anaesthesia.

This study compared the efficacy and safety of single oral doses of 60 mg/kg and 90 mg/kg paracetamol in fit young adult patients undergoing third molar extractions. The study was a randomised, blinded, crossover design on 20 young, fit adults. Paracetamol was administered 30 minutes prior to the surgical extraction of the teeth, which was done under intravenous sedation and local anaesthesia. There were no clinically or statistically significant differences in the pain scores between 60 mg/kg or 90 mg/kg doses until the intake of rescue analgesics. There was a reduction in factor VII activity with 90 mg/kg dose compared to 60 mg/kg dose. It may be concluded that the 90 mg/kg dose, though safe, does not offer any advantages over 60 mg/kg dose of paracetamol in young fit adults undergoing third molar surgery.

Diagnostics and therapy of lymphoceles after kidney transplantation.

Lymphocele incidence after kidney transplantation is as high as 18%. We retrospectively studied the therapy of 42 lymphoceles that occurred in our clinic between 1990 and 2005, focusing on possible predisposing factors for their formation and the results of several therapy variants: conservative, operative, percutaneous puncture, and laparoscopic or open marsupialization. There was no connection between lymphocele formation and the following parameters: the extent to which the iliac vessels had been prepared, the materials used for the preparation, or whether clips or ligatures were applied. Lymphoceles may originate either from the lymphatic system of the recipient or the transplanted kidney. The most sensible measures to prevent their occurrence therefore seems to be to restrict the transplant bed to the smallest permissible level with careful ligature of the lymphatic vessels in the area of the kidney hilus. Treatment for lymphoceles should start with minimally invasive measures. We use the following algorithm in our clinic: puncture to differentiate between urinoma/lymphocele and to test for bacterial infection, sclerotization (200 mg doxycyclin), and finally marsupialization if persistent. The choice of operative technique depends on the location. This algorithm resulted in a relapse rate of 9.5% during the postoperative observation period of up to 15 years.

RNA aptamers as potential pharmaceuticals against infections with African trypanosomes.

Protozoal pathogens cause symptomatic as well as asymptomatic infections. They have a worldwide impact, which in part is reflected in the long-standing search for antiprotozoal chemotherapy. Unfortunately, effective treatments for the different diseases are by and large not available. This is especially true for African trypanosomiasis, also known as sleeping sickness. The disease is an increasing problem in many parts of sub-Saharan Africa, which is due to the lack of new therapeutics and the increasing resistance against traditional drugs such as melarsoprol, berenil and isometamidium. Considerable progress has been made over the past 10 years in the development of nucleic acid-based drug molecules using a variety of different technologies. One approach is a combinatorial technology that involves an iterative Darwinian-type in vitro evolution process, which has been termed SELEX for "systematic evolution of ligands by exponential enrichment". The procedure is a highly efficient method of identifying rare ligands from combinatorial nucleic acid libraries of very high complexity. It allows the selection of nucleic acid molecules with desired functions, and it has been instrumental in the identification of a number of synthetic DNA and RNA molecules, so-called aptamers that recognize ligands of different chemical origin. Aptamers typically bind their target with high affinity and high specificity and have successfully been converted into pharmaceutically active compounds. Here we summarize the recent examples of the SELEX technique within the context of identifying high-affinity RNA ligands against the surface of the protozoan parasite Trypanosoma brucei, which is the causative agent of sleeping sickness.

Interventions for protecting renal function in the perioperative period.

BACKGROUND: A number of methods have been used to try to protect kidney function in patients undergoing surgery. These include the administration of dopamine, diuretics, calcium channel blockers, angiotensin converting enzyme inhibitors and hydration fluids. OBJECTIVES: For this review, we selected randomized controlled trials, which employed different methods to protect renal function during the perioperative period. In examining these trials, we looked at outcomes such as renal failure and mortality, as well as changes in the renal function tests, including urine output, creatinine clearance, free water clearance, fractional excretion of sodium and renal plasma flow. SEARCH STRATEGY: We searched the Cochrane Central register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 4, 2004), MEDLINE (1966 to 2004) and EMBASE (1988 to 2004) and hand searched six journals (British Journal of Anaesthesia; Anesthesia and Analgesia; Anesthesiology; Annals of Surgery; Journal of Thoracic and Cardiovascular Surgery and Journal of Vascular Surgery). SELECTION CRITERIA: We selected all randomized controlled trials in adult population undergoing surgery where a treatment measure was used for the purpose of renal protection in the perioperative period. DATA COLLECTION AND ANALYSIS: We selected 37 studies for inclusion in this review. As well as analysis of the data from all the studies, we also performed subgroup analysis for type of interventions, types of surgical procedures and those with pre-existing renal dysfunction. We undertook sensitivity analysis on studies with high methodological quality. MAIN RESULTS: The review included data from 37 studies, comprising a total of 1227 patients. Of these, 658 received some form of treatment and 569 acted as controls. The interventions were mostly employing different pharmaceutical agents such as dopamine, diuretics, calcium channel blockers. ACE inhibitors or selected hydration fluids. The results indicated that certain interventions showed some benefits, but all the results suffered from significant heterogeneity. Hence we can draw no conclusions about the effectiveness of these interventions in protecting the kidneys during surgery. AUTHORS' CONCLUSIONS: There is no reliable evidence from available literature to suggest that interventions during surgery can protect the kidneys from damage. However, there is a need for more studies of high methodological quality. One particular area for further studies may be on patients with pre-existing renal dysfunction undergoing surgery.