Preparation and Characterization of a Rifampicin Coamorphous Material with Tromethamine Coformer: An Experimental-Theoretical Study.

Rifampicin (RIF) is an antibiotic used to treat tuberculosis and leprosy. Even though RIF is a market-available drug, it has a low aqueous solubility, hindering its bioavailability. Among the strategies for bioavailability improvement of poorly soluble drugs, coamorphous systems have been revealed as an alternative in the increase of the aqueous solubility of drug systems and at the same time also increasing the amorphous state stability and dissolution rate when compared with the neat drug. In this work, a new coamorphous form from RIF and tromethamine (TRIS) was synthesized by slow evaporation. Structural, electronic, and thermodynamic properties and solvation effects, as well as drug-coformer intermolecular interactions, were studied through density functional theory (DFT) calculations. Powder X-ray diffraction (PXRD) data allowed us to verify the formation of a new coamorphous. In addition, the DFT study indicates a possible intermolecular interaction by hydrogen bonds between the available amino and carbonyl groups of RIF and the hydroxyl and amino groups of TRIS. The theoretical spectra obtained are in good agreement with the experimental data, suggesting the main interactions occurring in the formation of the coamorphous system. PXRD was used to study the physical stability of the coamorphous system under accelerated ICH conditions (40 °C and 75% RH), indicating that the material remained in an amorphous state up to 180 days. The thermogravimetry result of this material showed a good thermal stability up to 153 °C, and differential scanning calorimetry showed that the glass temperature (Tg) was at 70.0 °C. Solubility studies demonstrated an increase in the solubility of RIF by 5.5-fold when compared with its crystalline counterpart. Therefore, this new material presents critical parameters that can be considered in the development of new coamorphous formulations.

Surgical management of Chiari II malformation: a systematic review of literature.

PURPOSE: Chiari II malformation (CM-II) is a congenital malformation of the posterior fossa associated with myelomeningocele. Of the symptomatic patients, 10-33% require surgical treatment. To this date, there is not a consensus about the best surgical technique, and whether to do duroplasty. METHODS: A literature search of the PubMed database and crossed references was performed, per PRISMA guidelines. Data regarding demographic features, extent of cervicomedullary deformity, clinical presentation, surgical techniques, and clinical outcomes were extracted. Pearson's chi-squared test was applied. The p-values under 0.05 were considered statistically significant. RESULTS: Twenty studies (N = 330) were analyzed. C3 and C4 levels represented 56.4% of the lowest tonsil displacement. The most reported symptom was dysphagia/swallowing dysfunction (53.8%). Suboccipital craniectomy (SOC) and cervical spine expansion (CSE) with duroplasty were the most reported technique. Dural augmentation was performed in 57.4% of the patients. After surgery, 59.6% observed an improvement in symptoms and quality of life, 12.5% were unchanged, and 27.8% had a worsened clinical status. The mortality rate was 2.5% during the first month after surgery, and 17.4% at the last follow-up evaluation. Patients who underwent CSE presented a better clinical outcome (p = 0.002). The SOC procedure could not be correlated with symptom improvement (p = 0.06). CONCLUSION: CM-II is associated with high morbidity and mortality. An early onset symptomatic CM-II demands intervention, which provided an improvement of outcome in most patients included in this review. The best surgical technique and the exact effect of the surgical management of CM-II on mortality are not yet clear.

Three New Polyprenylated Benzophenone Derivatives Isolated from Clusia burle-marxii.

Three new polyprenylated benzophenone derivatives named burlemarxione G-I (1-3) were isolated from C. burle-marxii trunks (compound 1) and leaves (compounds 2 and 3), along with the known compound burlemarxione F. Burlemarxione G (1) was isolated after methylation with diazomethane and it is the keto-enol tautomeric pair of burlemarxione F. Burlemarxione H (2) derives from burlemarxiones F and G, but it has additional rings due to cyclization of the prenyl group attached to C-5 that establishes new single bonds between C-1 and C-23, as well as, between C-24 and C-29. Burlemarxione I (3) has two additional cyclizations: the first encompasses the cyclization of the former isopentenyl group into an 11,11-dimethyl-six-membered ring, whereas the second produces additional rings due to the cyclization of the prenyl group attached to C-5 that establishes new single bonds between C-1 and C-23, as well as, between C-24 and C-29. All three compounds showed moderate anti-glioma activity. These results show that C. burle-marxii is an important source of sophisticated polyprenylated benzophenone derivatives.

Antimicrobial Potential of Chitosan Films Incorporated with Alcoholic Extract from Mimosa tenuiflora Leaves.

Antimicrobial films were prepared with chitosan containing the methanolic extract of M. tenuiflora leaves (FECT20%, FECT30%, and FECT40%), and their antimicrobial activities were evaluated by agar diffusion. The films were characterized by IR spectroscopy, scanning electron microscopy (SEM) and TG/DTG curves. TG/DTG curves showed thermal stability of chitosan-extract films up to 166 ºC. Micrographs of chitosan-extract films revealed an increase in porosity with the addition of extract. The FECT40% film showed inhibition zone diameters (IZ) against Micrococcus luteus, Staphylococcus aureus, Bacillus subtilis, and B. cereus, ranging from 1.0 ± 0.02 to 0.72 ± 0.09 cm. Only FECT30% and FECT40% inhibited the P. aeruginosa with IZs of 0.68 ± 0.02 and 0.77 ± 0.06 cm, respectively. In turn, the extract showed inhibition against B. subtilis and B. cereus, with IZs values of 0.92 ± 0.2 cm and 0.72 ± 0.05 cm, respectively. Additionally, the crude extract presented antioxidant potential with inhibition percentages of 32.74% ± 0.90 for ABTS and 27.04% ± 1.36 for DPPH. The antimicrobial and antioxidant activities of the crude extract, as well as the antimicrobial property of chitosan-extract films, suggests the potential of these biopolymers for the development of wound healing bandages and new food packaging alternatives.

Molecular Docking and GC/MS-Based Approach for Identification of Anxiolytic Alkaloids from Griffinia (Amaryllidaceae) Species in a Zebrafish Model.

Griffinia gardneriana Ravenna, Griffinia liboniana Morren and Griffinia nocturna Ravenna (Amarillydaceae) are bulbous plants found in tropical regions of Brazil. Our work aimed to determine the alkaloid profiles of Griffinia spp. and evaluate their anxiolytic potential through in vivo and in silico assays. The plants grown in greenhouses were dried and their ground bulbs were subjected to liquid-liquid partitions, resulting in alkaloid fractions that were analyzed by gas chromatography coupled to mass spectrometry (GC-MS). Anxiolytic activity was evaluated in zebrafish (Danio rerio) through intraperitoneal injection at doses of 40, 100 and 200 mg/kg in light-dark box test. GC-MS analyses revealed 23 alkaloids belonging to different skeleton types: lycorine, homolychorine, galanthamine, crinine, haemanthamine, montanine and narcisclasine. The chemical profiles were relatively similar, presenting 8 alkaloids common to the three species. The major component for G. gardneriana and G. liboniana was lycorine, while G. nocturna consisted mainly of anhydrolycorine. All three alkaloid fractions demonstrated anxiolytic effect. Furthermore, pre-treatment with diazepam and pizotifen drugs was able to reverse the anxiolytic action, indicating involving the GABAergic and serotonergic receptors. Molecular docking showed that the compounds vittatine, lycorine and 11,12-dehydro-2-methoxyassoanine had high affinity with both receptors, suggesting them to be responsible for the anxiolytic effect.

Ammonia Detection by Electronic Noses for a Safer Work Environment.

Providing employees with proper work conditions should be one of the main concerns of any employer. Even so, in many cases, work shifts chronically expose the workers to a wide range of potentially harmful compounds, such as ammonia. Ammonia has been present in the composition of products commonly used in a wide range of industries, namely production in lines, and also laboratories, schools, hospitals, and others. Chronic exposure to ammonia can yield several diseases, such as irritation and pruritus, as well as inflammation of ocular, cutaneous, and respiratory tissues. In more extreme cases, exposure to ammonia is also related to dyspnea, progressive cyanosis, and pulmonary edema. As such, the use of ammonia needs to be properly regulated and monitored to ensure safer work environments. The Occupational Safety and Health Administration and the European Agency for Safety and Health at Work have already commissioned regulations on the acceptable limits of exposure to ammonia. Nevertheless, the monitoring of ammonia gas is still not normalized because appropriate sensors can be difficult to find as commercially available products. To help promote promising methods of developing ammonia sensors, this work will compile and compare the results published so far.

Levonorgestrel intrauterine system versus dienogest effect on quality of life of women with deep endometriosis: a randomized open-label clinical trial.

Women with deep infiltrating endometriosis (DIE) can benefit from the use of progestins. Our aim is to explore if levonorgestrel-releasing intrauterine system (LNG-IUS) non inferior to dienogest (DNG) in improving deep endometriosis women's quality of life (QoL). This randomized open-label clinical trial included forty women with DIE assessed using clinical history and physical examination, transvaginal ultrasonography and magnetic resonance of the pelvis without any previous surgical treatment, with two treatments arms. The two groups underwent a 3-month washout of hormonal treatments, and then received either DNG or LNG-IUS for 6 months. QoL was assessed prior to and 6 months after the intervention, using the SF36 and the EHP30. DNG and LNG-IUS showed an increase on all domains of the SF36 (p < .001). There was no difference between treatments on the improvement observed (p > .05 for all domains). DNG and LNG-IUS, also, showed improvement on all domains of EHP30 (p < .001), except "relationship with children" and "feelings about pregnancy." However, there was no statistical difference between treatments for all sections scores (p > .05). The treatment of deep endometriosis symptoms using either DNG or LNG-IUS in women with no prior surgical treatment is associated with improvement in QoL.Trial Registration Number: This trial is registered on "The Brazilian Registry of Clinical Trials (ReBECID: RBR-8fjx2jp)," that is part of Primary Registries in the WHO Registry Network, under the title: "Dienogest versus Levonorgestrel IUS on deep endometriosis patient´s QoL without surgery" on June 14, 2021; https://ensaiosclinicos.gov.br/rg/RBR-8fjx2jp.

Advances in the expression and purification of human PARP1: A user-friendly protocol.

The PARP1 (Poly (ADP-ribose) polymerase 1) enzyme is essential for single and double-strand break repair in humans. Alterations affecting PARP1 activity have severe consequences for human health and are associated with pathologies like cancer, and metabolic and neurodegenerative disorders. Here, we have developed a fast and easy procedure for the expression and purification of PARP1. Biologically active protein was purified to an apparent purity > 95%, with only two purification steps. A thermostability analysis revealed that PARP1 possessed improved stability in 50 mM Tris-HCl pH 8.0 (Tm = 44.2 ± 0.3 °C), thus this buffer was used throughout the whole purification procedure. The protein was shown to bind to DNA and has no inhibitor molecules bound to the active site. Finally, the yield of the purified PARP1 protein is sufficient for both biochemical, biophysical and structural analysis. The new protocol provides a fast and simple purification procedure while producing similar protein quantities to what has been described previously.

Metabolism Characterization and Chemical and Plasma Stability of Casearin B and Caseargrewiin F.

Oral preparations of Casearia sylvestris (guacatonga) are used as antacid, analgesic, anti-inflammatory, and antiulcerogenic medicines. The clerodane diterpenes casearin B and caseargrewiin F are major active compounds in vitro and in vivo. The oral bioavailability and metabolism of casearin B and caseargrewiin F were not previously investigated. We aimed to assess the stability of casearin B and caseargrewiin F in physiological conditions and their metabolism in human liver microsomes. The compounds were identified by UHPLC-QTOF-MS/MS and quantified by validated LC-MS methods. The stability of casearin B and caseargrewiin F in physiological conditions was assessed in vitro. Both diterpenes showed a fast degradation (p < 0.05) in simulated gastric fluid. Their metabolism was not mediated by cytochrome P-450 enzymes, but the depletion was inhibited by the esterase inhibitor NaF. Both diterpenes and their dialdehydes showed a octanol/water partition coefficient in the range of 3.6 to 4.0, suggesting high permeability. Metabolism kinetic data were fitted to the Michaelis-Menten profile with KM values of 61.4 and 66.4 µM and Vmax values of 327 and 648 nmol/min/mg of protein for casearin B and caseargrewiin F, respectively. Metabolism parameters in human liver microsomes were extrapolated to predict human hepatic clearance, and suggest that caseargrewiin F and casearin B have a high hepatic extraction ratio. In conclusion, our data suggest that caseargrewiin F and casearin B present low oral bioavailability due to extensive gastric degradation and high hepatic extraction.

Prevalence of Trypanosoma lainsoni and its effects of parasitism on the health of non-volant small mammals from the Brazilian Cerrado.

Small mammals are important hosts and/or reservoirs of Trypanosoma spp. This study aimed to verify the prevalence of Trypanosoma spp. in non-volant small mammals from the Brazilian Cerrado and to test the effects of T. lainsoni on the neutrophil/lymphocyte ratio (N/L) and body condition in rodent and marsupial populations. For this, we collected blood samples of 293 individuals captured in five forest fragments between 2019 and 2020. Blood was used to prepare the blood smears and packed on filter paper for DNA extraction. Generalized linear models were performed to test the effects of T. lainsoni on host health. The DNA was submitted to nested PCR targeting the Trypanosoma spp. 18S rRNA gene. From blood smears analyzed by microscopy, we obtained a positivity rate of 7.2% for Trypanosoma spp. About 31.1% of Gracilinanus agilis, Didelphis albiventris, and Rhipidomys macrurus samples were positive in nested PCR. From the obtained sequences, 83.3% were genetically identical to T. lainsoni and about 11% to T. cruzi TcI. In addition, we reported the infection of T. lainsoni in Hylaeamys megacephalus. We suggest that T. lainsoni does not influence the body condition and N/L ratio for either G. agilis or R. macrurus. Overall, our results expand the host list of T. lainsoni and demonstrate the infection of small mammals by T. cruzi TcI in peri-urban areas.

Metabolite Profiling of Pleurotus ostreatus Grown on Sisal Agro-Industrial Waste Supplemented with Cocoa Almond Tegument and Wheat Bran.

Pleurotus ostreatus is an edible fungus with high nutritional value that uses industrial and agricultural lignocellulosic residues as substrates for growth and reproduction. Understanding their growth metabolic dynamics on agro-industrial wastes would help to develop economically viable and eco-friendly biotechnological strategies for food production. Thus, we used UHPLC/MS/MS and GNPS as an innovative approach to investigate the chemical composition of two strains of P. ostreatus, coded as BH (Black Hirataki) and WH (White Hirataki), grown on sisal waste mixture (SW) supplemented with 20 % cocoa almond tegument (CAT) or 20 % of wheat bran (WB). Metabolite dereplication allowed the identification of 53 metabolites, which included glycerophospholipids, fatty acids, monoacylglycerols, steroids, carbohydrates, amino acids, and flavonoids. This is the first report of the identification of these compounds in P. ostreatus, except for the steroid ergosterol. Most of the metabolites described in this work possess potential biological activities, which support the nutraceutical properties of P. ostreatus. Thus, the results of this study provide essential leads to the understanding of white-rot fungi chemical plasticity aiming at developing alternative biotechnologies strategies for waste recycling.

Graphene Oxide Thin Films for Detection and Quantification of Industrially Relevant Alcohols and Acetic Acid.

Industrial environments are frequently composed of potentially toxic and hazardous compounds. Volatile organic compounds (VOCs) are one of the most concerning categories of analytes commonly existent in the indoor air of factories' facilities. The sources of VOCs in the industrial context are abundant and a vast range of human health conditions and pathologies are known to be caused by both short- and long-term exposures. Hence, accurate and rapid detection, identification, and quantification of VOCs in industrial environments are mandatory issues. This work demonstrates that graphene oxide (GO) thin films can be used to distinguish acetic acid, ethanol, isopropanol, and methanol, major analytes for the field of industrial air quality, using the electronic nose concept based on impedance spectra measurements. The data were treated by principal component analysis. The sensor consists of polyethyleneimine (PEI) and GO layer-by-layer films deposited on ceramic supports coated with gold interdigitated electrodes. The electrical characterization of this sensor in the presence of the VOCs allows the identification of acetic acid in the concentration range from 24 to 120 ppm, and of ethanol, isopropanol, and methanol in a concentration range from 18 to 90 ppm, respectively. Moreover, the results allows the quantification of acetic acid, ethanol, and isopropanol concentrations with sensitivity values of (3.03±0.12)∗104, (-1.15±0.19)∗104, and (-1.1±0.50)∗104 mL-1, respectively. The resolution of this sensor to detect the different analytes is lower than 0.04 ppm, which means it is an interesting sensor for use as an electronic nose for the detection of VOCs.

The State of the Art on Graphene-Based Sensors for Human Health Monitoring through Breath Biomarkers.

The field of organic-borne biomarkers has been gaining relevance due to its suitability for diagnosing pathologies and health conditions in a rapid, accurate, non-invasive, painless and low-cost way. Due to the lack of analytical techniques with features capable of analysing such a complex matrix as the human breath, the academic community has focused on developing electronic noses based on arrays of gas sensors. These sensors are assembled considering the excitability, sensitivity and sensing capacities of a specific nanocomposite, graphene. In this way, graphene-based sensors can be employed for a vast range of applications that vary from environmental to medical applications. This review work aims to gather the most relevant published papers under the scope of "Graphene sensors" and "Biomarkers" in order to assess the state of the art in the field of graphene sensors for the purposes of biomarker identification. During the bibliographic search, a total of six pathologies were identified as the focus of the work. They were lung cancer, gastric cancer, chronic kidney diseases, respiratory diseases that involve inflammatory processes of the airways, like asthma and chronic obstructive pulmonary disease, sleep apnoea and diabetes. The achieved results, current development of the sensing sensors, and main limitations or challenges of the field of graphene sensors are discussed throughout the paper, as well as the features of the experiments addressed.

Phototoxic Potential of Different DNA Intercalators for Skin Cancer Therapy: In Vitro Screening.

Photodynamic therapy is a minimally invasive procedure used in the treatment of several diseases, including some types of cancer. It is based on photosensitizer molecules, which, in the presence of oxygen and light, lead to the formation of reactive oxygen species (ROS) and consequent cell death. The selection of the photosensitizer molecule is important for the therapy efficiency; therefore, many molecules such as dyes, natural products and metallic complexes have been investigated regarding their photosensitizing potential. In this work, the phototoxic potential of the DNA-intercalating molecules-the dyes methylene blue (MB), acridine orange (AO) and gentian violet (GV); the natural products curcumin (CUR), quercetin (QT) and epigallocatechin gallate (EGCG); and the chelating compounds neocuproine (NEO), 1,10-phenanthroline (PHE) and 2,2'-bipyridyl (BIPY)-were analyzed. The cytotoxicity of these chemicals was tested in vitro in non-cancer keratinocytes (HaCaT) and squamous cell carcinoma (MET1) cell lines. A phototoxicity assay and the detection of intracellular ROS were performed in MET1 cells. Results revealed that the IC50 values of the dyes and curcumin in MET1 cells were lower than 30 µM, while the values for the natural products QT and EGCG and the chelating agents BIPY and PHE were higher than 100 µM. The IC50 of MB and AO was greatly affected by irradiation when submitted to 640 nm and 457 nm light sources, respectively. ROS detection was more evident for cells treated with AO at low concentrations. In studies with the melanoma cell line WM983b, cells were more resistant to MB and AO and presented slightly higher IC50 values, in line with the results of the phototoxicity assays. This study reveals that many molecules can act as photosensitizers, but the effect depends on the cell line and the concentration of the chemical. Finally, significant photosensitizing activity of acridine orange at low concentrations and moderate light doses was demonstrated.

Symptoms and Surgical Technique of Bladder Endometriosis: A Systematic Review.

OBJECTIVE: This systematic review aimed to review all the available evidence regarding bladder endometriosis (BE) surgical techniques, resolution of symptoms, and nodule size. DATA SOURCES: We conducted systematic searches in PubMed MEDLINE, Embase, Latin American and Caribbean Centre on Health Sciences Information, Cochrane Library, and Web of Science databases from inception to December 2021. METHODS OF STUDY SELECTION: Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, the literature search yielded 1279 articles. Two reviewers independently screened abstracts and reviewed full-text articles to meet the eligibility criteria: women diagnosed as having BE, treated surgically to remove the BE nodule, and reported of the nodule size and/or symptoms after the surgery. We included 28 studies, which mainly were case reports and case series. TABULATION, INTEGRATION, AND RESULTS: The following information was extracted from the included studies: author, country, publication year, study design, number of patients, age, surgery performed, follow-up time, operation time, nodule location, nodule size, and postsurgical symptoms. Patients' ages range from 26 to 44 years and most women were nulliparous. The BE nodule size ranged from 0.7 to 5.5 cm, and the most frequent location (63.57%) was the posterior wall. Dysuria was reported by 27.18% of women and generic lower urinary tract symptoms were reported by 27.95%. After surgery, the recurrence rate of urinary symptoms was 7.34%. Most studies performed a partial cystectomy to remove the nodule, showing that the disease affects the bladder mucosa frequently. CONCLUSION: Surgical treatment with complete excision of BE lesion was shown to improve complaints of urinary symptoms in patients with BE. Given that most of the studies evaluated were descriptive, additional studies with a large sample population and a better level of evidence for this condition are needed.

Conservative versus Radical Surgery for Women with Deep Infiltrating Endometriosis: Systematic Review and Meta-analysis of Bowel Function.

OBJECTIVE: To assess bowel function in women with deep infiltrating endometriosis according to surgical approach (radical vs conservative). DATA SOURCES: Five databases were searched from 1970 to September 2021 to retrieve studies comparing radical (colorectal segmental resection) and conservative (shaving or discoid excision) surgery for bowel function in women with deep infiltrating endometriosis. METHODS OF STUDY SELECTION: No language restriction was applied. Two reviewers extracted and combined data from the included studies, applying a meta-analytic model with random effects in all calculations. Results are expressed in risk ratio (RR) with 95% confidence interval (CI). Assessment of risk of bias and quality of evidence was performed by the Newcastle-Ottawa and Grading of Recommendations, Assessment, Development and Evaluation, respectively. TABULATION, INTEGRATION, AND RESULTS: We included 13 studies in our meta-analysis, and most of them were of nonrandomized design. Conservative surgery had fewer events of constipation and frequent bowel movements when compared with radical surgery (RR, 2.31; 95% CI, 1.21-4.43; I2 = 0%; 3 studies; RR, 2.80; 95% CI 1.17-6.75; I2 = 0%; 2 studies, respectively). Defecation pain, anal incontinence loss, minor and major lower anterior resection syndrome, and Clavien-Dindo complications grade I to IV showed no statistically significant difference between surgeries. Grading of Recommendations, Assessment, Development and Evaluation assessment was low to very low for all outcomes. CONCLUSION: Conservative surgery (shaving or discoid excision) presented fewer events of constipation and frequent bowel movements than colorectal segmental resection. There was a very low quality of evidence to provide recommendations regarding bowel function.

Intracranial thrombosis after ventriculoperitoneal shunting.

We report a case of intracranial thrombosis (IT) after ventriculoperitoneal shunting (VPS). We reviewed the literature to highlight the importance of considering the possibility of cerebral venous thrombosis following VPS, even though it is a rarely reported complication. A 14-year-old boy underwent distal catheter replacement due to its short size that was detected during a routine consultation. Five days postoperatively, he experienced nausea, vomiting, seizures, and headache. Although a diagnosis of meningitis was considered, diagnosis of IT was eventually confirmed through computed tomography venography and gadolinium magnetic angioresonance. The patient subsequently underwent anticoagulant therapy, which led to complete resolution of symptoms. In this report, we suggest a possible association between VPS and IT, which is a complication that is not commonly reported. The literature suggests that decreased blood flow due to over-drainage of CSF after VPS causes decreased head pressure, culminating in venous stasis and consequent thrombosis. In addition, the literature describes associations between IT and lumbar puncture (LP); therefore, it is important to consider the possibility of IT following these procedures.

Fetal epidural hematoma secondary to a mild blunt prenatal trauma: case report and review of the literature.

Fetal intracranial hemorrhage affects 1 in every 10,000 pregnancies. In most cases, the etiology of the bleeding is multifactorial, and they can be either related to the mother or the fetus. Blunt prenatal trauma was occasionally associated with these hemorrhages, nevertheless, reports of hematomas secondary to mild traumas are rare. Within the prenatal intracranial bleedings, the most frequent are the subarachnoid hematoma and intraparenchymal, scarcely ever the epidural hematoma. Treating these bleedings is challenging due to the ongoing pregnancy. Thus, the prognosis is often reserved, with a mortality rate of 43% and 25% of neurological sequelae. Here, we report a singular case of a fetal epidural hematoma secondary to a mild blunt trauma at the third trimester with a good outcome.

Acceleration strategies for Tridimensional Coupled hydromechanical problems based on CPU and GPU programming in MATLAB.

Large-scale fluid flow in porous media demands intense computations and occurs in the most diverse applications, including groundwater flow and oil recovery. This article presents novel computational strategies applied to reservoir geomechanics. Advances are proposed for the efficient assembly of finite element matrices and the solution of linear systems using highly vectorized code in MATLAB. In the CPU version, element matrix assembly is performed using conventional vectorization procedures, based on two strategies: the explicit matrices, and the multidimensional products. Further assembly of the global sparse matrix is achieved using the native sparse function. For the GPU version, computation of the complete set of element matrices is performed with the same strategies as the CPU approach, using gpuArray structures and the native CUDA support provided by MATLAB Parallel Computing Toolbox. Solution of the resulting linear system in CPU and GPU versions is obtained with two strategies using a one-way approach: the native conjugate gradient solver (pcg), and the one provided by the Eigen library. A broad discussion is presented in a dedicated benchmark, where the different strategies using CPU and GPU are compared in processing time and memory requirements. These analyses present significant speedups over serial codes.

Volatile Organic Compound Monitoring during Extreme Wildfires: Assessing the Potential of Sensors Based on LbL and Sputtering Films.

A new theory suggests that flammable gases generated by heated vegetation, in particular the volatile organic compounds (VOC) common to Mediterranean plants, may, under certain topographic and wind conditions, accumulate in locations where, after the arrival of the ignition source, they rapidly burst into flames as explosions. Hence, there is a need for the development of a system that can monitor the development of these compounds. In this work, a sensor's array is proposed as a method for monitoring the amount of eucalyptol and α-pinene, the major VOC compounds of the Eucalyptus and Pine trees. The detection of the target compounds was assessed using the impedance spectroscopy response of thin films. Combinations of layers of polyelectrolytes, such as poly(allylamine hydrochloride) (PAH), polyethyleneimine (PEI), poly(sodium 4-sytrenesulfonate) (PSS) graphene oxide (GO), and non/functionalized multiwall nanotubes (MWCNT-COOH or MWCNT), namely, PAH/GO, PEI/PSS, PEI/GO, PAH/MWCNT, PAH/MWCNT-COOH, films, and TiO2 and ZnO sputtered films, were deposited onto ceramic supports coated with gold interdigitated electrodes. The results showed that concentrations of the target VOCs, within the range of 68 to 999 ppmv, can be easily distinguished by analyzing the impedance spectra, particularly in the case of the ZnO- and PAH/GO-film-based sensors, which showed the best results in the detection of the target compounds. Through principal component analysis (PCA), the best set of features attained for the ZnO and PAH/GO based sensor devices revealed a linear trend of the PCA's first principal component with the concentration within the range 109 and 807 ppmv. Thus, the values of sensitivity to eucalyptol and α-pinene concentrations, which were (2.2 ± 0.3) × 10-4 and (5.0 ± 0.7) × 10-5 per decade, respectively, as well as resolutions of 118 and 136 ppbv, respectively, were identified.