Hydrogen production from food wastes and gas post-treatment by CO2 adsorption

The production of H(2) by biological means, although still far from being a commercially viable proposition, offers great promise for the future. Purification of the biogas obtained may lead to the production of highly concentrated H(2) streams appropriate for industrial application. This research work evaluates the dark fermentation of food wastes and assesses the possibility of adsorbing CO(2) from the gas stream by means of a low cost biomass-based adsorbent. The reactor used was a completely stirred tank reactor run at different hydraulic retention times (HRTs) while the concentration of solids of the feeding stream was kept constant. The results obtained demonstrate that the H(2) yields from the fermentation of food wastes were affected by modifications in the hydraulic retention time (HRT) due to incomplete hydrolysis. The decrease in the duration of fermentation had a negative effect on the conversion of the substrate into soluble products. This resulted in a lower amount of soluble substrate being available for metabolisation by H(2) producing microflora leading to a reduction in specific H(2) production. Adsorption of CO(2) from a gas stream generated from the dark fermentation process was successfully carried out. The data obtained demonstrate that the column filled with biomass-derived activated carbon resulted in a high degree of hydrogen purification. Co-adsorption of H(2)S onto the activated carbon also took place, there being no evidence of H(2)S present in the bio-H(2) exiting the column. Nevertheless, the concentration of H(2)S was very low, and this co-adsorption did not affect the CO(2) capture capacity of the activated carbon.

The influence of the precursor and synthesis method on the CO2 capture capacity of carpet waste-based sorbents

Adsorption is one of the most promising technologies for reducing CO(2) emissions and at present several different types of sorbents are being investigated. The use of sorbents obtained from low-cost and abundant precursors (i.e. solid wastes) appears an attractive strategy to adopt because it will contribute to a reduction not only in operational costs but also in the amount of waste that is dumped and burned in landfills every year. Following on from previous studies by the authors, in this work several carbon-based adsorbents were developed from different carpet wastes (pre-consumer and post-consumer wastes) by chemical activation with KOH at various activation temperatures (600-900 °C) and KOH:char impregnation ratios (0.5:1 to 4:1). The prepared materials were characterised by chemical analysis and gas adsorption (N(2), -196 °C; CO(2), 0 °C), and tested for CO(2) adsorption at temperatures of 25 and 100 °C. It was found that both the type of precursor and the conditions of activation (i.e. impregnation ratios, and activation temperatures), had a huge influence on the microporosity of the resultant samples and their CO(2) capture capacities. The carbon-based adsorbent that presented the maximum CO(2) capture capacities at 25 and 100 °C (13.8 wt.% and 3.1 wt.%, respectively), was prepared from a pre-consumer carpet waste and was activated at 700 °C using a KOH:char impregnation ratio of 1:1. This sample showed the highest narrow microporosity volume (0.47 cm(3) g(-1)), thus confirming that only pores of less than 1 nm are effective for CO(2) adsorption at atmospheric pressure.

Comparison of a low-pressure and a high-pressure pulsatile lavage during débridement for orthopaedic implant infection

INTRODUCTION

The aim of our study was to compare the effectiveness of high-pressure pulsatile lavage and low-pressure lavage in patients with an orthopaedic implant infection treated with open débridement followed by antibiotic treatment.

PATIENTS AND METHODS

Patients with an orthopaedic implant infection requiring open débridement from January 2008 to August 2009 were randomized prospectively to a low-pressure or a high-pressure pulsatile lavage arm. Relevant information about demographics, co-morbidity, type of implant, microbiology data, surgical treatment, and outcome were recorded. Comparison of proportions was made using χ(2) test or Fisher exact test when necessary. The Kaplan-Meier survival method was used to estimate the cumulative probability of treatment failure from open débridement to the last visit.

RESULTS

Seventy-nine patients were included. There were no differences between the main characteristics between both groups (p > 0.05). Mean (SD) age of the whole cohort was 70.2 (11.9) years. There were 46 infections on knee prosthesis, 17 on hip prosthesis, 7 on hip hemiarthroplasties and 9 on osteosynthesis devices. There were 69 acute post-surgical infections, 8 acute haematogenous infections and 2 chronic infections. The most common microorganisms isolated were coagulase-negative Staphylococci in 34 cases, Staphylococcus aureus in 26 and Escherichia coli in 19 cases. There were 30 polymicrobial infections. A total of 42 and 37 patients were randomized to a high-pressure pulsatile or a low-pressure lavage, respectively. There was no difference in the success rate between both arms (80.9 vs. 86.5%, p = 0.56).

CONCLUSION

The use of a high-pressure pulsatile lavage during open débridement of implant infections had a similar success rate as a low-pressure lavage.

Extracts of edible and medicinal plants in inhibition of growth, adherence, and cytotoxin production of Campylobacter jejuni and Campylobacter coli

Campylobacter spp. is recognized as one of the most common cause of food-borne bacterial gastroenteritis in humans. Campylobacter infection causes campylobacteriosis, which can range from asymptomatic to dysentery-type illnesses with severe complications, such as Guillian-Barre syndrome. Epidemiological studies have revealed that consumption of poultry products is an important risk factor of this disease. Adherence and cytotoxic activity of the bacteria to host mucosal surfaces have been proposed to be critical steps in pathogenesis. Innovative tools for controlling Campylobacter, such as natural products from plants, represent good alternatives for use in foods or as therapeutic agents. In this study, 28 edible or medicinal plants species were analyzed for their bactericidal effects on the growth of Campylobacter jejuni and C. coli. The extracts of Acacia farnesiana, Artemisia ludoviciana, Opuntia ficus-indica, and Cynara scolymus were the most effective against these microorganisms at minimal bactericidal concentrations (MBCs) of 0.3, 0.5, 0.4, and 2.0 mg/mL, respectively. No effect on growth was detected with lower concentrations of extract (25%, 50%, or 75% of the MBC) added to the media. The effect of each extract (75% of the MBC) on adherence and cytotoxicity of C. jejuni and C. coli was evaluated in Vero cells. Adherence of Campylobacter to Vero cells was significantly affected by all the extracts. Cytotoxic activity of bacterial cultures was inhibited by A. farnesiana and A. ludoviciana. These plant extracts are potential candidates to be studied for controlling Campylobacter contamination in foods and the diseases associated with this microorganism.

PRACTICAL APPLICATION

Innovative tools for controlling Campylobacter, such as natural products from plants, represent good alternatives for use in foods or as therapeutic agents. The extracts of Acacia farnesiana, Artemisia ludoviciana, Opuntia ficus-indica, and Cynara scolymus were the most effective against these microorganisms. Adherence and cytotoxic activity of the bacteria to host mucosal surfaces which are critical steps in pathogenesis were decreased by these extracts. Our results point to these plants as potential candidates for the control of Campylobacter contamination in foods, the treatment of the diseases associated with this microorganism, and as feed supplements to reduce on-farm prevalence of Campylobacter.

Equimolar nitrous oxide/oxygen versus placebo for procedural pain in children: a randomized trial

OBJECTIVE

This randomized, single-dose, double-blind, Phase III study was designed to compare the level of procedural pain after use of premixed equimolar mixture of 50% oxygen and nitrous oxide (EMONO) or placebo (premixed 50% nitrogen and oxygen).

METHODS

Patients aged 1 to 18 years were randomly assigned to receive EMONO (n = 52) or placebo (n = 48) delivered by inhalation through a facial mask 3 minutes before cutaneous, muscle, or bone/joint procedures. Pain was evaluated (on a scale from 0-10) using a self-reported Faces Pain Scale-Revised (FPS-R) or a Spanish observational pain scale (LLANTO). Rescue analgesia (with propofol or sevoflurane) was administered if pain scores were greater than or equal to 8. Collaboration, acceptance, ease of use and safety were evaluated by the attending nurse.

RESULTS

There were significant differences between the 2 groups (EMONO versus placebo) for both scales (mean values): LLANTO: 3.5 vs 6.7, respectively (P = .01) and FPS-R: 3.2 vs 6.6, respectively (P = .0003). Patients not receiving EMONO (P = .0208)-in particular those aged younger than 3 years (P < .0001)-required more rescue analgesia. There were also significant differences between the 2 groups (EMONO versus placebo) for adequate collaboration (80% vs 35%; P < .0001) and acceptance (73% vs 25%; P < .0001). Ease of use was not significantly different between groups (98.1% vs 95.8%; P > .05). Only 2 patients (in the EMONO group) presented with mild adverse events.

CONCLUSIONS

EMONO inhalation was well tolerated and had an estimated analgesic potency of 50%, and it is therefore suitable for minor pediatric procedures.

Detection of zoonotic intestinal parasites in public parks of Spain. Potential epidemiological role of microsporidia

Several studies have demonstrated that the soil of public parks presents an important source of infection which has a significant impact on public health. Children are the main group affected by accidentally ingestion of contaminated soil. This study was performed in order to identify the presence of zoonotic parasites in dog and cat faecal and soil samples from public parks of Madrid, Spain. Six hundred twenty-five and seventy-nine soil and faecal samples (presumably from dogs and cats) respectively were collected from 67 parks. Intestinal parasites were identified in 27 parks (40.3%), which were contamined with Giardia sp. (19.4%), microsporidia (19.4%), Toxocara spp. (16.4%), Cryptosporidium sp. (6%), Entamoeba histolytica (3%) and Ancylostomidae (3%). Combinations of two or more intestinal parasites were found in 11 parks, and it was common to find Giardia and microsporidia together in samples. Intestinal parasites were detected in 18% (112/625) of soil samples. The most frequent parasite species found in the examined soil samples were Toxocara spp. (16.4%), followed by Giardia sp. (4.5%) and Strongyloides sp. larvae (3%). The zoonotic parasites found in the 79 faecal samples were Giardia sp. (17.7%), Cryptosporidium sp. (9%), E. histolytica (2.5%), Trichuris vulpis (1.3%), Toxascaris leonina (1.3%) and microsporidia spores (28%). Microsporidia characterization by amplification of DNA confirmed 10 samples as positive, eight for E. bieneusi and two for E. hellem by PCR. The role of those parasites in the environment are discussed.

A charcoal- and blood-free enrichment broth for isolation and PCR detection of Campylobacter jejuni and Campylobacter coli in chicken

The microaerophilic nature of Campylobacter and its requirement of ∼5% O(2) for growth have complicated its recovery from foods. The addition to the enrichment media of oxygen quenchers such as charcoal or blood could interfere with PCR for its detection. In this study, a two-step simple aerobic method for Campylobacter detection is proposed. A modification of the Tran blood-free enrichment broth (BFEB), in which charcoal was excluded from the medium (M-BFEB), was compared with the original formulation and other enrichment broths. Campylobacter jejuni and Campylobacter coli were screened by PCR directly from the enrichment media. Various levels of pure cultures of C. jejuni and C. coli combined with Escherichia coli were inoculated into Preston, Bolton, BFEB, and the modified BFEB (M-BFEB). In addition, Campylobacter was inoculated onto retail purchased chicken skin and recovery was quantified. Rates of recovery after 24 to 48 h of enrichment at 42 °C under aerobic incubation for BFEB and M-BFEB and microaerobic incubations for Preston and Bolton broths were determined. Overall, our results indicated that the most sensitive medium was Bolton's, followed by either BFEB or M-BFEB; the least sensitive was Preston's. M-BFEB was directly coupled to a PCR assay to detect Campylobacter, avoiding intermediate plating. Campylobacter was detected in the presence of up to 10(8) E. coli cells per ml. M-BFEB facilitated detection of both C. jejuni and C. coli artificially inoculated onto chicken skin samples. M-BFEB coupled to PCR is a rapid and attractive alternative for isolation and identification of C. coli and C. jejuni from poultry.

Extracts of Agave americana inhibit aflatoxin production in Aspergillus parasiticus

Toxigenic fungi invade crops prior to harvest as well as during storage and produce harmful, even carcinogenic toxins such as aflatoxins. Since consumers demand safe commodities, and due to enhanced public awareness of the dangers of many synthetic fungicides, the importance of investigating alternative, natural products to control these toxigenic fungi is clear. This study investigated the effect of aqueous extracts of Agave americana on growth, conidia and aflatoxin production. Aspergillus parasiticus strains SRRC 148, SRRC 143 (Su-1), and A. parasiticus SRRC 162, a mutant (nor-) that accumulates norsolorinic acid (NOR, an orange-coloured intermediate of the aflatoxin pathway), were first inoculated into Adye and Mateles liquid medium, then plant extracts were added, and incubated at 28 °C for 7 days. Aflatoxin and norsolorinic acid were assayed by HPLC and spectrophotometry, respectively. While the extract of A. americana stimulated growth of the studied fungi, conidiogenesis, norsolorinic acid accumulation (in the nor- mutant), and aflatoxin production were significantly affected. The reduction was produced by the extracts at concentrations higher than 5-10 mg/ml, where all types of total aflatoxin analysed (aflatoxins B1, B2, G1 and G2) were reduced from 64% to >99% in the whole culture, and a reduction of 75% of norsolorinic acid. The results of the present work indicate that extracts of A. americana may be promising safe alternatives to harmful fungicides for controlling aflatoxin contamination.

Adherence, invasion, toxigenic, and chemotactic properties of Mexican campylobacter strains

To determine the virulence factors of Mexican wild-type strains of Campylobacter jejuni and Campylobacter coli, 31 wild-type strains were isolated from food and from humans. The production of cytolethal distending toxin and the adherence and invasion capabilities of these strains were assayed in Vero cells. Hard agar plugs with repellents and attractants were used to examine chemotaxis. Mueller-Hinton agar with supplements was used for motility analysis and to measure hemolytic activity. Nine strains of C. jejuni and eight strains of C. coli exhibited motility, most within a diameter of 2 to 13 mm. Most of the strains reacted to the repellent compounds analyzed, and α- and β-like hemolysis and cytotoxicity in Vero cells were observed for all strains. Isolates adhered to and invaded Vero cells to various degrees. Although strains of C. jejuni exhibited stronger adherence but less invasion compared with strains of C. coli, the difference was not significant (P > 0.05). The strains of C. jejuni and C. coli isolated from food and from patients in Mexico could have major impacts on public health.

Reduction of Campylobacter jejuni and Campylobacter coli in poultry skin by fruit extracts

Campylobacter spp. are a major cause of foodborne bacterial gastroenteritis in humans, and current methods to control Campylobacter contamination in foods are not completely successful. Plants are a promising source of antimicrobial agents, particularly given the growing interest in "all natural" foods. In this study, the antimicrobial activity of extracts from 28 edible plants against Campylobacter jejuni and Campylobacter coli was evaluated in vitro and in a poultry skin model. Nine of 28 extracts exhibited antimicrobial activity in a diffusion assay, and MBCs were determined for the three most active extracts, i.e., lime, plum, and sour orange peel (MBCs of 2 to 3 mg/ml). Mixtures of the lime, plum, and sour orange peel extracts were applied to chicken skin inoculated with 10(5) CFU of Campylobacter to test for synergistic or antagonist effects. After incubation (48 h at 4 degrees C) with any extract mixture, no Campylobacter CFUs were detectable. A panel of tasters determined that the mixture of lime and plum gave the best flavor to chicken wings. These active extracts from edible fruits are simple to prepare and are alternatives to reduce or eliminate Campylobacter contamination of chicken products.

[How to identify adverse events in emergency services? A guide agreed for the screening]

OBJECTIVE

Since a third of adverse events (AE) occur outside hospital, the Emergency Services are a suitable place to look at their incidence. We considered designing a screening guide, adapted to the conditions of the emergency services, to identify AE.

MATERIAL AND METHODS

A qualitative technique was applied (nominal group) in which 14 professionals participated. They analysed which factors of intrinsic risk, extrinsic risk, and alert conditions, were suitable for a screening guide of AE in emergency services. The session was chaired by a specialist in these types of techniques.

RESULTS

Consensus was high in that the most frequent AE in emergencies were those related to medicines, diagnostic tests and with the correct identification of the reason for emergency. With respect to screening guide, the group proposed adding alcohol abuse, patient social problems, cognitive deterioration, basal autonomy and disability. In relation to extrinsic risk factors, they pointed to the need of including defibrillation, spinal tap or drainage implantation. With respect to the alert conditions form, the professionals agreed in that all the criteria seemed correct and suitable, except for that related to damage relation childbirth or amniocentesis.

CONCLUSIONS

By using this technique we have managed to validate materials already recognized, and widely used in our country. The screening guide was considered useful, with slight modifications in some risk factors and alert conditions. The professionals agreed that the MRF2 modular questionnaire is appropriate for the characterisation of AE in emergencies.

Application of robotic stereotactic radiotherapy to peripheral stage I non-small cell lung cancer with curative intent

AIMS

To determine the effectiveness of robotic stereotactic radiotherapy with image guidance and real-time respiratory tracking against early stage peripheral lung cancer.

MATERIALS AND METHODS

We treated patients with stage I non-small cell lung cancer (NSCLC) with CyberKnife and analysed their clinical characteristics and outcomes. All patients had co-morbid conditions that precluded lobectomy. The clinical target volume (CTV) included the gross tumour volume (GTV) and a 6mm margin in all directions to account for microscopic extension. The planning target volume (PTV) equalled CTV+2mm in all directions for uncertainty. Tumour motion was tracked using a combination of Synchrony and Xsight Spine tracking methods with the aid of a single gold marker implanted in the centre of the tumour, or using the newer Xsight Lung method without markers for selected tumours. A 60-67.5 Gy dose was prescribed to the 60-80% isodose line (median 65%) and given in three to five fractions. Patients were followed every 3 months for a median of 27.5 months (range 24-53 months).

RESULTS

Of the 67 patients with NSCLC stage IA or IB treated between January 2004 and December 2008, we report the results of a cohort of 31 with peripheral stage I tumours of 0.6-71 cm(3) volume treated between January 2004 and December 2007 with total doses between 60 and 67.5 Gy in three to five fractions. The median D(max) was 88.2 Gy and the median V(95) of the PTV was 99.6% or 27.9 cm(3). No grade 3 or above toxicity was encountered. Four cases of radiation pneumonitis and one case of oesophagitis were observed. In those patients whose pre- and post-treatment results were available, no change in pulmonary function tests was observed. Actuarial local control was 93.2% for 1 year and 85.8% for up to 4.5 years. One-year overall survival was 93.6% and 83.5% for up to 4.5 years, as projected by Kaplan-Meier analyses.

CONCLUSIONS

In this small cohort of patients with stage I peripheral NSCLC, robotic stereotactic radiotherapy seems to be a safe and obviously superior alternative to conventionally fractionated radiotherapy, with results that may be approaching those obtained with lobectomy without the associated morbidity.

Identification of risk factors associated with nosocomial infection by rotavirus P4G2, in a neonatal unit of a tertiary-care hospital

A rotavirus outbreak in newborns admitted to the 'La Paz' University Hospital, Madrid was detected, followed up and controlled. Uninfected children were selected as control subjects. Samples of faeces were taken once or twice weekly from all the newborns, including those who were asymptomatic and who were admitted to the neonatal unit for early detection of rotavirus and the positive were separated from the rest of the neonates. Contact-related precautions were taken for all patients, and alcohol solutions were used for hand washing. During the months of the outbreak, 1773 children were admitted to the hospital, 131 of whom were affected by the rotavirus infection (7.4%). Of these, 72 (55%) had symptomatic infections. In the first month of the outbreak, nine cases of necrotizing enterocolitis were diagnosed (one patient developed massive intestinal necrosis). The infections (symptomatic and asymptomatic) presented a bimodal distribution caused by a new outbreak of rotavirus type P4G2 after two patients who had acquired the infection outside the hospital were admitted when the first outbreak was subsiding. The characteristics of cases and controls were analysed using bivariate and multivariate methods (non-conditional multivariate logistic regression) to identify four risk factors strongly associated with rotavirus infection: premature birth, infections other than rotavirus, malformation, and changes in glycaemia and/or presence of jaundice.

[Potential use of bone marrow scintigraphy in suspected prosthetic hip infection evaluated with 99mTc-HMPAO-leukocytes]

AIM

To evaluate the usefulness of (99m)Tc-Sulphur colloid when combined with leukocyte scintigraphy in suspected prosthetic hip infection, comparing the results with information from (99m)Tc-HMPAO-leukocyte scintigraphy alone.

MATERIALS AND METHODS

Seventy patients (42 women, 28 men; mean age 68 +/- 13 years) with painful hip prostheses and suspicion of infection were evaluated prospectively. All patients had bone scintigraphy, (99m)Tc-HMPAO-labelled white blood cell scintigraphy and (99m)Tc-Sulphur colloid bone marrow scintigraphy. ESR and CRP levels were measured in all patients. The final diagnosis was made with microbiological findings or by clinical follow up of at least 12 months.

RESULTS

Infections were diagnosed in 12 of the 70 patients (3 coagulase-negative Staphylococcus, 2 Staphylococcus aureus, 2 Staphylococcus epidermidis, 2 enterococcus and 3 polymicrobial agents). ESR and CRP values were higher in patients with infection than in patients without infection (51.8 +/- 29.4 vs. 25.4 +/- 16.4 and 2.8 +/- 2.2 vs. 1.1 +/- 1.3, respectively; p < 0.05). Bone scintigraphy did not show a characteristic pattern to differentiate infection from aseptic loosening. The pool phase of the bone scintigraphy was positive in only 3/12 patients with infection (25 %). Sensitivity and specificity of the leukocyte scintigraphy was 83 % and 57 %, respectively. When the results of the bone marrow scintigraphy were added, these values increased to 92 % and 98 %, respectively.

CONCLUSION

Performing bone marrow scintigraphy significantly improves results when compared with leukocyte scintigraphy alone in the diagnosis of infected hip prostheses. Bone scintigraphy did not help to differentiate aseptic loosening from infection in this series.

[Diabetes mellitus in hypertensive population attended in Primary Care in Spain. Blood pressure and lipid control rates]

OBJECTIVES AND METHODS

The aim of this study was to determine the blood pressure and LDL-cholesterol (LDL-c) control rates of hypertensive patients with diabetes mellitus attended in primary care setting in Spain, and to compare the data with those of the hypertensive population without diabetes. For this purpose, we analyzed the subset of diabetic patients of those included in the PRESCOT study (a cross-sectional survey of hypertensive subjects > 18 years attended in primary care). 12,954 patients (49.9% females; 62.1 +/- 10.7 years) were included in the PRESCOT study. Good controls were considered blood pressure < 130/80 mmHg (according to European Society of Hypertension-European Society of Cardiology [ESH-ESC] guidelines) and LDL-c < 100 mg/dl (National Cholesterol Education Program-Adult Treatment Panel III [NCEP-ATP III]).

RESULTS

Overall, 3868 (29.9%) of PRESCOT patients were diabetics (mean age 64.2 +/- 9.8 years; 47.5% males). Almost all the diabetic patients (98.5%) were taking some drug besides the antidiabetic treatment and 84.9% were taking at least 2 drugs. Although diabetic patients were treated with more antihypertensive medication than those without diabetes (48.75% vs 40.85% were on > 2 drugs, p < 0.001), blood pressure control was much lower in diabetics (6.3% vs 32.7%, p < 0.0001). In the same way, LDL-c control was also lower in these patients (12.0% vs 31.9%, p < 0.0001). Only 1.0% of diabetic hypertensives were well controlled for both risk factors (vs 11.9% of non-diabetics, p < 0.0001). Predictors of bad blood pressure control were sedentarism and presence of associated clinical conditions, and for lipid control the younger age, female gender, overweight, alcoholism and non-use of lipid-lowering agents.

CONCLUSIONS

The presence of diabetes in hypertensive population attended in Spanish primary health care is frequent. One out of every three hypertensives who attend the outpatient clinic daily is diabetic. Even though more drugs are prescribed in these patients, blood pressure and LDL-c control rates are significantly lower than in patients without diabetes. In the daily practice of primary care setting, almost no diabetic hypertensive subject is well controlled for blood pressure and LDL-c.