Sequencing paired tumor DNA and white blood cells improves circulating tumor DNA tracking and detects pathogenic germline variants in localized colon cancer.

BACKGROUND: In the setting of localized colon cancer (CC), circulating tumor DNA (ctDNA) monitoring in plasma has shown potential for detecting minimal residual disease (MRD) and predicting a higher risk of recurrence. With the tumor-only sequencing approach, however, germline variants may be misidentified as somatic variations, precluding the possibility of tracking in up to 11% of patients due to a lack of known somatic mutations. In this study, we assess the potential value of adding white blood cells (WBCs) to tumor tissue sequencing to enhance the accuracy of sequencing results. PATIENTS AND METHODS: A total of 148 patients diagnosed with localized CC were prospectively recruited at the Hospital Clínico Universitario in Valencia (Spain). Employing a custom 29-gene panel, sequencing was conducted on tumor tissue, plasma and corresponding WBCs. Droplet digital PCR and amplicon-based NGS were performed on plasma samples post-surgery to track MRD. Oncogenic somatic variants were identified by annotating with COSMIC, OncoKB and an internal repository of pathogenic mutations database. A variant prioritization analysis, mainly characterized by the match of oncogenic mutations with the evidence levels defined in OncoKB, was carried out to select specific targeted therapies. RESULTS: Utilizing paired tumor and WBCs sequencing, we identified somatic mutations in all patients (100%) within our cohort, compared to 89% using only tumor tissue. Consequently, the top 10 most frequently mutated genes for plasma monitoring were altered. The sequencing of WBCs identified 9% of patients with pathogenic mutations in the germline, with APC and TP53 being the most frequently mutated genes. Additionally, mutations in genes related to clonal hematopoiesis of indeterminate potential were detected in 27% of the cohort, with TP53, KRAS, and KMT2C being the most frequently altered genes. There were no observed differences in the sensitivity of monitoring MRD using ddPCR or amplicon-based NGS (p = 1). Ultimately, 41% of the patients harbored potentially targetable alterations at diagnosis. CONCLUSION: The germline testing method not only enhanced sequencing results and raised the proportion of patients eligible for plasma monitoring, but also uncovered the existence of pathogenic germline variations, thereby aiding in the identification of patients at a higher risk of hereditary cancer syndromes.

Influence of Water on the Oxidation of NO on Pd/TiO2 Photocatalysts.

Two series of new photocatalysts were synthesized based on modification with Pd of the commercial P25 photocatalyst (EVONIK®). Two techniques were employed to incorporate Pd nanoparticles on the P25 surface: photodeposition (series Pd-P) and impregnation (series Pd-I). Both series were characterized in depth using a variety of instrumental techniques: BET, DRS, XRD, XPS, TEM, FTIR and FESEM. The modified series exhibited a significant change in pore size distribution, but no differences compared to the original P25 with respect to crystalline phase ratio or particle size were observed. The Pd0 oxidation state was predominant in the Pd-P series, while the presence of the Pd2+ oxidation state was additionally observed in the Pd-I series. The photoactivity tests were performed in a continuous photoreactor with the photocatalysts deposited, by dip-coating, on borosilicate glass plates. A total of 500 ppb of NO was used as input flow at a volumetric flow rate of 1.2 L·min-1, and different relative humidities from 0 to 65% were tested. The results obtained show that under UV-vis or Vis radiation, the presence of Pd nanoparticles favors NO removal independently of the Pd incorporation method employed and independently of the tested relative humidity conditions. This improvement seems to be related to the different interaction of the water with the surface of the photocatalysts in the presence or absence of Pd. It was found in the catalyst without Pd that disproportionation of NO2 is favored through its reaction with water, with faster surface saturation. In contrast, in the catalysts with Pd, disproportionation took place through nitro-chelates and adsorbed NO2 formed from the photocatalytic oxidation of the NO. This different mechanism explains the greater efficiency in NOx removal in the catalysts with Pd. Comparing the two series of catalysts with Pd, Pd-P and Pd-I, greater activity of the Pd-P series was observed under both UV-vis and Vis radiation. It was shown that the Pd0 oxidation state is responsible for this greater activity as the Pd-I series improves its activity in successive cycles due to a reduction in Pd2+ species during the photoactivity tests.

Broiler chicken myofiber morphometrics and myogenic stem cell population heterogeneity1,2.

Myogenic stem cells (MSC), also known as satellite cells, play a key role in mediating post-hatch skeletal muscle growth in broiler chickens. Information regarding the heterogeneity of MSC populations and myofiber size distributions in different muscles of modern broiler strains of both sexes is scarce. Thus, myofiber cross-sectional area (CSA) and myogenic regulatory factor expression by MSC populations in 2 functionally different muscles (Biceps femoris, BF and Pectoralis major, PM) from both sexes of broilers from 2 strains, Ross 708 x Ross 708 (ROSS; Aviagen Group, Huntsville, AL) and Red Ranger (RR; S&G Poultry, Clanton, AL) was evaluated. Female and male broilers from both strains (n = 80 birds per strain) were reared for 43 d on a common corn and soybean meal-based diet. At 43 d of age, 8 birds per sex per strain (n = 32 total) were euthanized and PM and BF muscle samples from each bird were analyzed using cryohistology, immunofluorescence (IF) staining, and fluorescence microscopy. Cryosections from each muscle from each bird were IF stained to detect Myf-5, MyoD, and Pax7-expressing MSC. The CSA of every fiber in each digital image was measured and MSC populations (Myf-5+, MyoD+, Pax7+, Myf-5+: MyoD+, Myf-5+: Pax7+, MyoD+: Pax7+, and Myf-5+: MyoD+: Pax7+) were enumerated. Myofiber CSA was similar among the 2 strains and 2 sexes (P > 0.05). As expected, mean myofiber CSA was greater in the predominantly fast-twitch PM than the predominantly slow-twitch BF muscle (P = 0.006). At 43 d of age, ROSS broilers had a 32% larger population of Myf-5+: MyoD+: Pax7+ MSC compared with RR (P = 0.04). The heterogeneity of MSC was similar among the sexes. While the total MSC population was larger in the BF muscle compared with the PM (P < 0.05), the Myf-5+ and Pax7+ MSC densities were similar among muscles (P > 0.05). The major differences in myofiber morphometrics and MSC heterogeneity were not among the different broiler strains or sexes but were instead, between the 2 functionally different muscles.

Search for antibodies to Taenia solium cysticerci in paediatric patients with seizures.

Neurocysticercosis is a leading cause of seizures in adults, but in paediatric patients, the diagnosis is controversial. The aim of this study was to search for antibodies to Taenia solium cysticerci in paediatric patients with seizures. We retrospectively studied a cohort of 41 serum samples from paediatric patients and 40 serum samples from healthy children. Antibodies were analysed by ELISA (vesicular fluid) and by Western blot (glycoproteins). Clinical, image and socio-demographic data were obtained from the medical records. The frequency of positive by ELISA was of 12% (n=5) in patients with seizures, while no positive samples were found in the healthy group. Results of Western blot were negatives. The analysis of the medical records showed a cyst of unknown origin in 2/5 ELISA positive samples. According to the diagnostic criteria for neurocysticercosis, three minor criteria (positive serology, active seizures and compatible image) were associated to an epidemiological condition (Mexico is endemic for neurocysticercosis); thus, the probable frequency of neurocysticercosis in the studied sample of patients with seizures was 4.9% (2/41 patients). The three remaining positive samples were associated with problems of noninfectious origin. The positivity was associated with the identification of cysts by magnetic resonance imaging (p = 0.047; chi-square), but found no association with the socio-economic characteristics of the patients, family history or to clinical symptoms. In conclusion, scarce frequency of antibodies to T. solium cysticerci was determined in paediatric patients with seizures. The low prevalence of antibodies detected in children is an indirect indicator of the interruption of T. solium transmission. Further studies are needed to design an algorithm for the conclusive diagnosis of seizures.

[The neural networks of facial expression]. / Redes neuronales de la expresion facial.

INTRODUCTION: Face perception involves a broad network of connections between cortical and subcortical regions for the exchange and synchronization of information using white matter fibers. This precise communication system can be affected by the structures and the pathways that connect them. AIMS: To establish the neural substrate underlying the perception of facial expression and to analyze the different factors involved in modulating the integrity of this neural network, with the aim being to introduce improvements into rehabilitation programs. DEVELOPMENT: When the complex neural network involved in the perception of facial expression is altered by trauma, neurodegenerative disorders, developmental disorders, social isolation or negative contexts, the adaptive capacity to interact with the environment also deteriorates. CONCLUSIONS: Maintaining the neural network integrity responsible for processing facial expression requires considering different variables. To a greater or lesser extent, these variables modify the structure or function of neural networks, such as aerobic training, transcranial magnetic stimulation, transcranial electrical stimulation, and learning. These variables are affected by age, and the type and course of the condition or generator context, and raise the need for rehabilitation protocols that are adapted and designed to delimit the deficient neuronal substrate.

TITLE: Redes neuronales de la expresion facial.Introduccion. La percepcion de caras involucra una amplia red de conexiones entre regiones corticales y subcorticales que intercambian y sincronizan informacion a traves de haces de sustancia blanca. Este preciso sistema de comunicacion puede verse afectado tanto a traves de las propias estructuras como por las vias que las conectan. Objetivos. Delimitar el sustrato neuronal que subyace a la percepcion de la expresion facial y analizar los diferentes factores que participan modulando la integridad de esta red neuronal, con el fin de proponer mejoras en los programas de rehabilitacion. Desarrollo. Cuando la compleja red de conexiones que participa en la percepcion de la expresion facial se altera por traumatismos, patologias neurodegenerativas, trastornos del desarrollo, incluso por aislamiento social o contextos negativos, se deteriora tambien la capacidad para interactuar de manera adaptativa con el entorno. Conclusiones. La posibilidad de restaurar la integridad de la red neuronal encargada del procesamiento de la expresion facial pasa por tener en cuenta diferentes variables que en mayor o menor grado se han mostrado capaces de modificar la estructura o funcionalidad de las redes neuronales, como el entrenamiento aerobico, la estimulacion magnetica transcraneal, la estimulacion electrica transcraneal y el aprendizaje, sin bien estas variables estarian condicionadas por la edad, el tipo y evolucion del trastorno o el contexto generador, lo que plantearia la necesidad de protocolos de rehabilitacion ajustados y orientados a delimitar el sustrato neuronal del deficit.

Breast cancer: determining the genetic profile from ultrasound-guided percutaneous biopsy specimens obtained during the diagnostic workups. / Cáncer de mama: determinación del perfil genético a partir de la biopsia percutánea ecoguiada diagnóstica.

OBJECTIVES: To evaluate the possibility of determining the genetic profile of primary malignant tumors of the breast from specimens obtained by ultrasound-guided percutaneous biopsies during the diagnostic imaging workup. MATERIAL AND METHODS: This is a retrospective study in 13 consecutive patients diagnosed with invasive breast cancer by B-mode ultrasound-guided 12 G core needle biopsy. After clinical indication, the pathologist decided whether the paraffin block specimens seemed suitable (on the basis of tumor size, validity of the sample, and percentage of tumor cells) before sending them for genetic analysis with the MammaPrint® platform. RESULTS: The size of the tumors on ultrasound ranged from 0.6cm to 5cm. In 11 patients the preserved specimen was considered valid and suitable for use in determining the genetic profile. In 1 patient (with a 1cm tumor) the pathologist decided that it was necessary to repeat the core biopsy to obtain additional samples. In 1 patient (with a 5cm tumor) the specimen was not considered valid by the genetic laboratory. The percentage of tumor cells in the samples ranged from 60% to 70%. In 11/13 cases (84.62%) it was possible to do the genetic analysis on the previously diagnosed samples. CONCLUSION: In most cases, regardless of tumor size, it is possible to obtain the genetic profile from tissue specimens obtained with ultrasound-guided 12 G core biopsy preserved in paraffin blocks.

Palm tree mulch as substrate for primary treatment wetlands processing high strength urban wastewater.

The life span of subsurface flow treatment wetlands is determined by the clogging of the substrate. Thus, the influent should undergo primary treatment to reduce loadings of suspended solids and dissolved organic matter. An-organic based substrate should be less prone to clogging because of its remarkably higher porosity and plasticity. Mulch obtained from branches of the Canarian palm tree (Phoenix canariensis) has been tested as substrate for mixed flow, intermittently fed treatment wetland mesocosms processing high strength urban wastewater. The effect of the presence of plants (Phragmites and Cyperus), influent pressure and hydraulic loading rate was studied. The best removals (SS: 89%, COD: 77%, turbidity: 82%) have been obtained with planted reactors treating highly concentrated influents at the lower hydraulic loading rates tested. The palm tree mulch units achieved similar removals of SS, COD and turbidity to one having gravel as substrate and planted with common reed. Mulch obtained from stems of giant reed (Arundo donax) provided similar removals of SS and turbidity but that of COD was lower. The combination of organic-based TWs with gravel-based ones provided high removals (SS: 95%, COD: 78%, turbidity: 95%) while the risk of clogging was strongly reduced.

Antimicrobial peptides as parasiticidal against human trypanosomatids: mechanisms of action and current status in development.

Trypanosomes cause a variety of tropical diseases that affect the livelihood of individuals worldwide. The currently used pharmaceutical treatments rely on chemotherapy. However, many of these drugs are very expensive, and highly toxic. In addition, parasite resistance to several of the therapeutic drugs used is increasing. Therefore, there is a growing need for new control measures for many of these diseases. One new approach is the use of antimicrobial peptides (AMPs) to disease control, since these peptides can be used as potential anti-parasite effector molecules. This review summarizes and discusses the parasiticidal properties of AMPs for treating trypanosome infections, highlighting their mechanisms of action and current status in development.

Oral reading fluency analysis in patients with Alzheimer disease and asymptomatic control subjects.

INTRODUCTION: Many studies highlight that an impaired ability to communicate is one of the key clinical features of Alzheimer disease (AD). OBJECTIVE: To study temporal organisation of speech in an oral reading task in patients with AD and in matched healthy controls using a semi-automatic method, and evaluate that method's ability to discriminate between the 2 groups. SUBJECTS AND METHODS: A test with an oral reading task was administered to 70 subjects, comprising 35 AD patients and 35 controls. Before speech samples were recorded, participants completed a battery of neuropsychological tests. There were no differences between groups with regard to age, sex, or educational level. RESULTS: All of the study variables showed impairment in the AD group. According to the results, AD patients' oral reading was marked by reduced speech and articulation rates, low effectiveness of phonation time, and increases in the number and proportion of pauses. Signal processing algorithms applied to reading fluency recordings were shown to be capable of differentiating between AD patients and controls with an accuracy of 80% (specificity 74.2%, sensitivity 77.1%) based on speech rate. CONCLUSION: Analysis of oral reading fluency may be useful as a tool for the objective study and quantification of speech deficits in AD.

Effect of additives in photocatalytic degradation of commercial azo dye Lanaset Sun Yellow 180.

The photocatalytic degradation of the commercial dye Lanaset Sun Yellow 180 was studied in the presence and absence of the different additives used in the dye's formulation. The experiments were performed with Degussa P25 as received and doped with Fe (Fe-TiO2) and a new catalyst synthesized by our research group (ECT-1023). The best efficiency was achieved with Fe-TiO2. With this catalyst, the formation of a photoactive complex was observed between the dye and Fe atoms of the catalyst surface that accelerated degradation. FTIR studies revealed that the complex was formed by interaction between the dye's carbonyl groups and the atoms of the metal. In mixtures of the dye containing citric acid or acetate, degradation was notably inhibited with the catalysts Fe-TiO2 and ECT-1023 because of the formation of carboxylates on their surface. This inhibitory effect was neutralized when all the additives were present in the solution. Toxicity analyses indicated that intermediates were not toxic. Thus, the photocatalytic methods seem to be optimal for the decolourization of wastewaters containing this dye.

[Management of appendicular mass]. / Tratamiento y seguimiento del plastrón apendicular.

BACKGROUND: Management of appendicular mass is still controversial. Some authors plead for an initial non-operative approach followed by a delayed appendectomy. OBJECTIVES: Our aim has been to revise the usefulness of this management and the optimal time to carry out the appendectomy. METHODS: We made a retrospective review of all the appendicular mass cases treated in our hospital during the last 8 years. We analyzed the success rate of the non-operative approach, the interval until the delayed appendectomy was performed, difficulty found at surgery and the occurred complications. RESULTS: Our series includes 19 appendicular mass cases managed initially by a non-operative approach. Intravenous antibiotics were administered to all of them and in 14 cases a peritoneal drainage was placed (the average length of stay was of 11.5 days). In 3 cases (16%) early appendectomy was performed (12, 30 and 40 days after the onset of the symptoms). In 16 (84%) the conservative approach succeeded and the appendectomy was delayed 3-12 months (average: 6.6 months). Four of them were performed by an open approach and 12 by laparoscopy (in 3 of which conversion was needed). The average length of stay was of 1.8 days, with only one complication (wound abscess). Of these 16 delayed appendectomies, 11 were not technically difficult to perform (average wait of 5.5 months) and in 5 cases the procedure was difficult due to multiple adhesions (average wait of 9.4 months). CONCLUSION: Conservative management of appendicular mass is useful, with a success rate of 84% in our series. The appendectomy was less hazardous if performed 3-6 months after the onset of the symptoms.

A study on parasites in Mexican rheumatic disease patients.

Blastocystis hominis is a common human parasite with infection rates up to 50% in developing countries, and giardiasis is the commonest intestinal one in Mexico. No doubt, various parasites as Giardia lamblia and Entamoeba histolytica can cause rheumatic diseases. This study coproparasitoscopic analysis evaluated the cysts by B. hominis, G. lamblia, E. hartmani, E. coli and E. histolytica in Mexican rheumatic disease patients. Also, ELISA was used to detect E. histolytica, Ascaris lumbricoides, Toxocara canis, and Trichinella spiralis in Mexican patients with rheumatoid arthritis (RA) and ankylosing spondylitis (AS). Thirty-six patients (24 with AS and 12 with RA) and 77 healthy control individuals were enrolled in this study. The frequencies of protozoan cysts were comparable in rheumatic disease patients (AS and RA) and healthy control donors (33 and 25 vs. 26%, respectively; p > 0.05). The frequency of antibodies to T. canis was significantly higher in AS patients than in healthy control donors (16 vs. 2.6%, respectively; p = 0.027), whereas no differences were observed for the prevalence of antibodies for the other parasites (E. histolytica, A. lumbricoides and T. spiralis) (p > 0.05). This information indicates the need to intensify educational efforts for the prevention of parasite infections associated with AS disease that cannot be controlled only by drugs.

Morphometric analysis of nodules in human onchocerciasis collected in communities of the southern Chiapas focus, México.

Human onchocerciasis is a disease that remains as an important public health problem. The morphometric and physical characteristics of 363 Onchocerca volvulus nodules collected in the major endemic focus of onchocerciasis in Southern Chiapas (Soconusco), was assessed. In the present work we found that treatment the morphometry of 363 onchocercal nodules preserved in a 67% glycerol solution was determined by measuring the length, width and thick of each nodule with a Vernier caliper. The mass was determined with an analytical balance and the volume by measuring the water displacement, while the specific gravity was calculated by dividing mass over the volume. Statistical analysis was calculated for each parameter. The results showed that the nodules were rather longer than wider or thicker. Morphometric characteristics were 9.87 +/-3.70 (mean +/- standard deviation), 7.52 +/- 2.81, and 4.62 +/-+/- 2.06 mm for length, width and thick respectively. In regard to the shape, 62.81% of the nodules showed a lenticular shape, while 18.18% were spherical and 19.01% were ovoid. Based on the distribution of frequencies of the length, the nodules were classified in three groups: the "small" (5.77 +/- 0.73 mm; n = 104, 28.65%), the "medium" group (9.86 +/- 2.05 mm; n = 203 nodules, 55.92%), and the group of the "big" ones (16.03 +/- 1.91 mm; n = 56, 15.43%). Moreover, the physical characteristics were: for the mass 0.33 +/- 0.24 g, the volume of displaced water was 0.28 +/- 0.26 ml, and the specific gravity was 1.10 +/- 0.55 g/ml. The results indicated that most of the Mexican Onchocerca nodules have a lenticular shape with average size of 10x7x5 mm, which is useful in the knowledge of the genus biodiversity and can be taken as a parameter in clinical or epidemiological trials, where onchocerciasis remains as a public health problem.

Degradation and detoxification of 4-nitrophenol by advanced oxidation technologies and bench-scale constructed wetlands.

The degradation and detoxification towards the duckweed Lemna minor of 4-nitrophenol (4NP) was studied by means of bench-scale constructed wetlands (CWs), TiO(2)-photocatalysis and Fenton + photoFenton reactions. The main goal of this work was to compare the three treatment techniques to evaluate their possible combination for the efficient, low cost treatment of 4NP effluents. In CWs, adsorption on the substrate of 4NP was found to achieve 34-45%. Low concentrations (up to 100 ppm) of 4NP were successfully treated by CWs in 8-12 h. The microbial degradation of 4NP started after a lag phase which was longer with higher initial concentrations of the pollutant. The greatest degradation rate was found to occur at initial concentrations of 4NP between 60 and 90 ppm. Solar TiO(2)-photocatalysis was faster than the CWs. The greatest removals in terms of mass of 4NP removed after 6 h of irradiation were found to occur at 4NP concentrations of about 200 ppm. Fenton reaction provided complete 4NP degradation up to 500 ppm in only 30 min but TOC was removed by only about 40%. The resulting toxicities were below 20% for initial 4NP concentrations below 300 ppm. It was the Fenton + photoFenton combination (180 min in total) that provided TOC reductions up to 80% and negative L. minor growth inhibition for almost all the 4NP concentrations tested. The combination of solar TiO(2)-photocatalysis (6 h) with CWs (16 h) was able to completely treat and detoxify 4NP effluents with concentrations as high as 200 ppm of the organic.

[Laparoscopic appendectomy after the learning curve]. / La apendicectomía laparoscópica más allá de la curva de aprendizaje.

BACKGROUND: Despite its increasing popularity, laparoscopic appendectomy does not put an unanimous end to the answer to the best treatment for appendicitis. Although the postoperative stay is shorter, the wound infection practically does not exist and scars are minimal, some publications question its advantages due to the incidence of intra-abdominal absceses, postoperative analgesia requirements and the recently described "postlaparoscopic appendectomy complication" (PLAC), an intra-abdominal infection, without abscess formation, which develops after laparoscopic appendectomy for non-complicated appendicitis. Some of this series include the "learning curve", wherein they compare results of inexperienced surgeons in laparoscopic techniques with those obtained after with the firmly established open appendectomy (OA) technique. With the aim to clarify this aspects, we reviewed our experience in laparoscopic appendectomy during (LDC) and after (LAC) the "learning curve" and we compared their complications with the open appendectomies' ones. METHODS: We retrospectively reviewed 807 appendectomies: 208 laparoscopic (LA) and 599 open (OA) from January 2001 to December 2007 performed in our hospital. In the laparoscopic group, 83 of them (40%) were done during the learning curve (each surgeon's 35 first interventions, LDC) and 125 (60%) after the learning curve (LAC). We have compared both laparoscopic subgroups to each other and to the open appendectomies group. We analysed the age, sex, length of stay, kind of appendicitis (simple or perforated appendicitis) and five of the most serious complications: intra-abdominal abscess, postoperative intestinal occlusion, intestinal perforation, haemorrhage and PLAC. RESULTS: The mean age (9 years), sex (58% men; 42% women) and the peritonitis rate (30%) were similar among the 3 groups. The mean length of stay was reduced from 5.4 days in OA group to 4.2 days in LA group and 3.6 days in LAC group (p < 0.01). The simple appendicitis cases had the shortest length of stay: 3.41 days in OA group and 2.16 days in LA group (p < 0.0001). There were no differences in stay for the peritonitis group. In the OA group, we detected 56 severe complications (9,3%): 49 abcesses, 2 occlusions, 2 PLAC, 1 haemorrhage, 1 intestinal perforation and 1 liver abscess. Nineteen severe complications were found in LDC group (22,9%): 9 abscesses, 4 occlusions, 4 haemorrhages, 1 intestinal perforation and 1 PLAC (p < 0.01 vs OA group). In the LAC group, we found 13 complications (10,4%): 9 abscesses, 1 occlusion, 1 PLAC and 2 haemorrhages (p = 0.3 vs OA group). CONCLUSIONS: 1. The length of stay was significantly reduced in laparoscopic appendectomies. 2. Severe complications, particularly intestinal occlusions and haemorrhages, increased significantly during the learning curve, with a slight fluctuation for intra-abdominal abscesses and PLAC. 3. After the learning curve, complications' global rate was similar to the OA group's, with an increment of haemorrhages and occlusions, no variation for PLAC and a slight reduction for intra-abdominal abscesses. 4. In our experience, laparoscopic appendectomy after the learning curve is the best therapeutic option for acute appendicitis.

Combining TiO2-photocatalysis and wetland reactors for the efficient treatment of pesticides.

In the present work the photocatalytic and biological degradation of two commercial mixtures of pesticides (Folimat and Ronstar) and two fungicides (pyrimethanil and triadimenol) has been studied. The evolution of some components of these commercial products (dicofol, tetradifon and oxadiazon) and that of the two fungicides has been monitored by means of HPLC, GC-MS, TOC and toxicity (Lemna minor toxicity test) measurements. The photocatalytic method was able to degrade dicofol, tetradifon, pyrimethanil, triadimenol and the components of Ronstar with the exception of oxadiazon. In addition to this, the photocatalytic method eliminated pyrimethanil toxicity and reduced that of triadimenol by a 90%, Ronstar by a 78% and Folimat by an 87%. Nevertheless, the wetland reactors alone could reduce the toxicity of only the former. Finally, the proper dosage of the water containing the pesticides to a photocatalytic reactor followed by a wetland reactor resulted to be the most successful strategy for the detoxification of the studied compounds and their mixtures.

Photocatalytic degradation of phenol and phenolic compounds Part I. Adsorption and FTIR study.

With the goal of predicting the photocatalytic behaviour of different phenolic compounds (catechol, resorcinol, phenol, m-cresol and o-cresol), their adsorption and interaction types with the TiO(2) Degussa P-25 surface were studied. Langmuir and Freundlich isotherms were applied in the adsorption studies. The obtained results indicated that catechol adsorption is much higher than those of the other phenolics and its interaction occurs preferentially through the formation of a catecholate monodentate. Resorcinol and the cresols interact by means of hydrogen bonds through the hydroxyl group, and their adsorption is much lower than that of catechol. Finally, phenol showed an intermediate behaviour, with a Langmuir adsorption constant, K(L), much lower than that of catechol, but a similar interaction. The interaction of the selected molecules with the catalyst surface was evaluated by means of FTIR experiments, which allowed us to determine the probability of OH radical attack to the aromatic ring.

Photocatalytic degradation of formaldehyde containing wastewater from veterinarian laboratories.

The photocatalytic destruction of methanol, formaline (mixture of formaldehyde, methanol and water) and formaline wastes from the preservation of vertinarian physiologic samples has been attempted by two different processes, at high concentrations of reagents and by dossification of reagents, varying pH in both. Experiment evolution has been monitored by measuring the organic matter such as TOC and formaldehyde concentrations [H2CO]. Also, methanol and methanol-formaldehyde interactions with the TiO2 surface have been analysed by FTIR spectroscopy. Results indicate that at high concentrations the catalyst surfacial alterations given by methoxy, formates or carbonates, according to the pH of the sample can profoundly affect catalyst behaviour. It has been established that reagent dossification is advantageous for enhancing photonic efficiency as it minimizes the adsorbate presence that hampers the photocatalytic process.