High-retention membrane bioreactors for sugarcane vinasse treatment: Opportunities for environmental impact reduction and wastewater valorization.

Ethanol production has increased over the years, and Brazil ranking second in the world using sugarcane as the main raw material. However, 10-15 L of vinasse are generated per liter of ethanol produced. Besides large volumes, this wastewater has high polluting potential due to its low pH and high concentrations of organic matter and nutrients. Given the high biodegradability of the organic matter, the treatment of this effluent by anaerobic digestion and membrane separation processes results in the generation of high value-added byproducts such as volatile fatty acids (VFAs), biohydrogen and biogas. Membrane bioreactors have been widely evaluated due to the high efficiency achieved in vinasse treatment. In recent years, high retention membrane bioreactors, in which high retention membranes (nanofiltration, reverse osmosis, forward osmosis and membrane distillation) are combined with biological processes, have gained increasing attention. This paper presents a critical review focused on high retention membrane bioreactors and the challenges associated with the proposed configurations. For nanofiltration membrane bioreactor (NF-MBR), the main drawback is the higher fouling propensity due to the hydraulic driving force. Nonetheless, the development of membranes with high permeability and anti-fouling properties is uprising. Regarding osmotic membrane bioreactor (OMBR), special attention is needed for the selection of a proper draw solution, which desirably should be low cost, have high osmolality, reduce reverse salt flux, and can be easily reconcentrated. Membrane distillation bioreactor (MDBR) also exhibit some shortcomings, with emphasis on energy demand, that can be solved with the use of low-grade and residual heat, or renewable energies. Among the configurations, MDBR seems to be more advantageous for sugarcane vinasse treatment due to the lower energy consumption provided by the use of waste heat from the effluent, and due to the VFAs recovery, which has high added value.

On the Mechanical Properties of Popgraphene-Based Nanotubes: a Reactive Molecular Dynamics Study.

Carbon-based tubular materials have sparked a great interest in future electronics and optoelectronics device applications. In this work, we computationally studied the mechanical properties of nanotubes generated from popgraphene (PopNTs). Popgraphene is a 2D carbon allotrope composed of 5-8-5 rings. We carried out fully atomistic reactive (ReaxFF) molecular dynamics for PopNTs of different chiralities ( n,0 and 0,n ) and/or diameters and at different temperatures (from 300 up to 1200 K). Results showed that the tubes are thermally stable (at least up to 1200 K). All tubes presented stress/strain curves with a quasi-linear behavior followed by an abrupt drop of stress values. Interestingly, armchair-like PopNTs ( 0,n ) can stand a higher strain load before fracturing when contrasted to the zigzag-like ones ( n,0 ). Moreover, it was obtained that Young's modulus (YMod ) (750-900 GPa) and ultimate strength (σUS ) (120-150 GPa) values are similar to the ones reported for conventional armchair and zigzag carbon nanotubes. YMod values obtained for PopNTs are not significantly temperature-dependent. While the σUS values for the 0,n showed a quasi-linear dependence with the temperature, the n,0 exhibited no clear trends.

A new method for measuring pen pressure in forensic handwriting analysis - a proof of concept study.

This work describes a new method for the analysis of handwritten documents through a system composed of a pre-selector optical analyser equipped with light sources of different wavelengths coupled with bandpass filters combined with an optical coherence tomography (OCT) instrument. The optical analyser identifies regions with different pen pressures on the paper using specific wavelengths from ultraviolet (UV) to infrared (IR) and bandpass filters. Then the selected regions are analysed with a coherence tomography analyser to measure the depth of grooves and capture three-dimensional images. With this methodology, it is possible to identify similarities, or differences, between the pieces of evidence under investigation, increasing the possibility of correct attribution concerning the authorship of the signature and we also showed that this feature is independent of the paper substrate. In this work, a new strategy will be presented to categorize and quantify pen pressure in order to aid a better response for a forensic examiner. Thereby, from the observed areas that display higher pressures (more significant grooves), it is possible to determine the authorship of the signature.

Detection of Toxoplasma gondii DNA in Brazilian oysters (Crassostrea rhizophorae).

The aim of this study was to detect evidence of Toxoplasma gondii using polymerase chain reaction (PCR)-based techniques in oysters (Crassostrea rhizophorae) obtained from the southern coastal region of Bahia, Brazil. A total of 624 oysters were collected, and the gills and digestive glands were dissected. Each tissue sample was separated into pools containing tissues (of the same type) from three animals, leading to a total of 416 experimental samples for analysis (208 samples each from the gills and digestive glands). Molecular analysis using PCR-based detection of the T. gondii AF 146527 repetitive fragment yielded negative results for all samples. However, when nested-PCR was used for detection of the T. gondii SAG-1 gene, 17 samples were positive, with the gills being the tissue with maximal detection of the parasite. These positive results were confirmed by sample sequencing. It is therefore suggested that C. rhizophorae oysters are capable of filtering and retaining T. gondii oocysts in their tissue. This represents a risk to public health because they are traditionally ingested in natura.

Large polarons in two-dimensional fullerene networks: the crucial role of anisotropy in charge transport.

The recent synthesis of a two-dimensional quasi-hexagonal-phase monolayer network of C60 molecules, known as qHPC60, holds significant promise for future semiconductor applications. However, the mechanism behind charge transport in these networks remains unknown. In this study, we developed a Holstein-Peierls Hamiltonian model to investigate charge transport in qHPC60, incorporating both local and non-local electron-phonon couplings. Our computational approach involved identifying suitable semi-empirical parameters to realize the formation of stable polarons in this material. The results unveiled the formation of stable large polarons as the primary carriers in the charge transport throughout qHPC60. To explore polaron transport properties, we conducted dynamic simulations within the picosecond time scale while subjecting the system to an external electric field. Our analysis emphasized the substantial influence of anisotropy on shaping mobile polarons, with an anisotropy coefficient of at least 50%. The polarons exhibited velocities within the acoustic regime ranging from 0.5-1.5 nm ps-1. While these velocities are comparable to those observed in high-end organic molecular crystals, they are considerably lower than those in graphene and conducting polymers. With qHPC60 possessing a semiconducting band gap of approximately 1.6 eV, our findings shed light on its potential application in flat electronics, overcoming the null-gap predicament of graphene.

On the mechanical properties and fracture patterns of the nonbenzenoid carbon allotrope (biphenylene network): a reactive molecular dynamics study.

Recently, a new two-dimensional carbon allotrope named biphenylene network (BPN) was experimentally realized. The BPN structure consists of four-, six-, and eight-membered rings of sp2-hybridized carbon atoms. In this work, we carried out fully-atomistic reactive (ReaxFF) molecular dynamics simulations to study the mechanical properties and fracture patterns of non-defective and defective (nanocracks) BPN. Results show that, under uniaxial tensile loading, BPN is converted into four distinct morphologies before fracture starts. This conversion process is dependent on the stretching direction. Some of the formed structures contain mainly eight-membered rings, which have different shapes in each morphology. In one of them, a graphitization process occurs before the complete fracture. Importantly, in the presence of nanocracks, no new morphologies are formed. BPN exhibits a distinct fracture process when contrasted to graphene. After the critical strain threshold, the graphene transitions from an elastic to a brittle regime, while BPN can exhibit different inelastic stages. These stages are associated with the appearance of new morphologies. However, BPN shares some of the exceptional graphene properties. BPN Young's modulus and melting point are comparable to graphene, about 1019.4 GPa and 4024 K, respectively.

Role of NO-cGMP pathway in ovine cervical relaxation induced by Erythroxylum caatingae Plowman.

Erythroxylum caatingae Plowman has a myorelaxing effect on smooth muscle tissue. We investigated the effect of the crude ethanolic extract of E. caatingae Plowman (Ec-EtOH) on the contractility of the ovine cervix. In an isometric system, circular strips were subjected to 90mM potassium (K(+)) or 30µM carbamylcholine (CCh)-induced contraction. We then exposed the tissue to cumulative concentrations of Ec-EtOH (1-729 µg/ml). In other bath solutions, the tissues were exposed to l-NG-nitroarginine methyl ester (l-NAME; 100µM), l-NAME (100µM)+l-arginine (300µM), 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, ODQ; 5µM), 4-aminopyridine (4-AP; 3mM), tetraethylammonium (TEA; 0.3mM), glybenclamide (1µM), atosiban (10µM) or verapamil (3µM), followed by the addition of Ec-EtOH (1-729 µg/ml). We also evaluated the effect of cervical Ec-EtOH infusion (2mg) on cervical contractility in vivo. Ec-EtOH decreased cervical contractility induced by K(+) or CCh, and 729 µg/ml Ec-EtOH decreased 85.4±5.1% the amplitude of basal contractility in vitro, with an EC50 of 17.9±3.7 µg/ml. This effect of Ec-EtOH was prevented by l-NAME or ODQ. l-arginine impaired the blunting effect of l-NAME on cervical relaxation caused by Ec-EtOH. However, the potassium channel blockers 4-AP, TEA, and glybenclamide did not modify this myorelaxation triggered by Ec-EtOH. Ec-EtOH also decreased acetylcholine-induced contractions in tissue preincubated with verapamil. In addition, Ec-EtOH decreased ovine cervical contractions in vivo. Thus, Ec-EtOH had a relaxant effect on ovine cervical contractions. This may involve the nitric oxide signal, mediated by cGMP cellular transduction, and be related to intracellular calcium sequestration.

Acaricidal activity of extracts from the leaves and aerial parts of Neoglaziovia variegata (Bromeliaceae) on the cattle tick Rhipicephalus (Boophilus) microplus.

This experiment was carried out to study the bioacaricidal activity of Neoglaziovia variegata against engorged females of Rhipicephalus (Boophilus) microplus. The mortality and fecundity of groups of engorged adult females exposed to different concentrations of ethanol, hexane, chloroform, and ethyl acetate extracts obtained from the leaves and aerial parts of N. variegata were evaluated, using three treatments with concentrations of 5, 10 e 25 mg/ml; two controls (distilled water and distilled water with drops of cremophor); with three replicates. The hexane extract of the leaves demonstrated significant results, presenting 94.1% inhibition of oviposition; 0.33% the average percentage of eclosion of eggs; and 99.8% of effectiveness. These results indicate N. variegata, particularly the hexane extract of leaves, as potential alternative control agents of R. (B.) microplus. Pharmacological and chemical studies are continuing in order to characterize the mechanism responsible for this effect.

Snake bites by the jararacuçu (Bothrops jararacussu): clinicopathological studies of 29 proven cases in São Paulo State, Brazil.

The jararacuçu, one of the most dreaded snakes of Brazil, southern Bolivia, Paraguay and northeastern Argentina, is a heavily-built pit viper which may grow to a length of 2.2 m. Up to 1000 mg (dry weight) of highly-lethal venom may be milked from its venom glands on a single occasion. It has accounted for 0.8% to 10% of series of snake bites in São Paulo State, Brazil. We examined 29 cases of proven jararacuçu bites recruited over a 20-year period in two São Paulo hospitals. Severe signs of local and systemic envenoming, (local necrosis, shock, spontaneous systemic bleeding, renal failure) were seen only in patients bitten by snakes longer than 50 cm; bites by shorter specimens were more likely to cause incoagulable blood. Fourteen patients developed coagulopathy, six local necrosis (requiring amputation in one) and five local abscesses. Two became shocked and four developed renal failure. Three patients, aged 3, 11 and 65 years, died 18.75, 27.75 and 83 h after being bitten, with respiratory and circulatory failure despite large doses of specific antivenom and intensive-care-unit management. In two patients, autopsies revealed acute renal tubular necrosis, cerebral oedema, haemorrhagic rhabdomyolysis at the site of the bite and disseminated intravascular coagulation. In one survivor with chronic renal failure, renal biopsy showed bilateral cortical necrosis; the patient remains dependent on haemodialysis. Effects of polyspecific Bothrops antivenom were not impressive, and it has been suggested that anti-Bothrops and anti-Crotalus antivenoms should be given in combination.

Prognostic factors for local necrosis in Bothrops jararaca (Brazilian pit viper) bites.

The prognostic factors related to envenoming are not very well known. This study aims to identify prognostic factors for necrosis in envenoming by Bothrops jararaca. We analysed 779 medical records of patients bitten by B. jararaca and treated at the Hospital Vital Brazil, Butantan Institute, São Paulo, Brazil, between 1982 and 1990: 111 cases with necrosis were compared with the remaining cases. The length of the snake, the bite site, the month of the accident, pain, oedema, ecchymosis, blisters, systemic bleeding, shock, and the use of tourniquet were statistically associated with the presence of necrosis (P < 0.05) in the univariate analysis. The size of the snake, the bite site (leg and finger), the sex of the patient, the month of the accident, systemic bleeding, and the use of tourniquet were independent prognostic factors within the variables tested in the multivariate analysis. The size of the snake was the most important independent prognostic factor related to the presence of necrosis.

Failure of chloramphenicol prophylaxis to reduce the frequency of abscess formation as a complication of envenoming by Bothrops snakes in Brazil: a double-blind randomized controlled trial.

Bites by many species of venomous snake may result in local necrosis at, or extending from, the site of the bite. The use of prophylactic antibiotics to prevent infection as a complication of local necrotic envenoming is controversial. A double-blind randomized controlled trial was carried out to assess whether antibiotic therapy is effective in this situation. Two hundred and fifty-one patients, with proven envenoming by snakes of the genus Bothrops, admitted to two hospitals in Brazil, between 1990 and 1996, were randomized to receive either oral chloramphenicol (500 mg every six hours for five days) or placebo. One hundred and twenty-two of these patients received chloramphenicol (group 1) and 129 were given placebo (group 2). There were no significant differences between the groups at the time of admission. Necrosis developed in seven (5.7%) patients in group 1 and in five (3.9%) patients in group 2 (P>0.05) while abscesses occurred in six patients (4.9%) in group 1 and in six (4.7%) patients in group 2 (P>0.05). In conclusion, the use of orally-administered chloramphenicol for victims of Bothrops snake bite with signs of local envenoming on admission, is not effective for the prevention of local infections.

Bites by the colubrid snake Philodryas olfersii: a clinical and epidemiological study of 43 cases.

Less than 10 cases of bites by Philodryas olfersii (Colubridae) have been reported in the literature. In this study, 43 patients admitted to the Instituto Butantan, São Paulo, Brazil, with the diagnosis of P. olfersii bite from 1982 to 1990 were reviewed. The 32 male (74.4%) and 11 female (25.6%) patients presented mainly from November to February (65%). The most common clinical features were local pain (37.2%), swelling (34.9%), erythema (18.6%) and ecchymosis (9.3%). The 20 minute whole blood clotting test was performed in 11 patients and in all of them the blood was coagulable. Most of the accidents occurred during the hottest months and during daylight hours. The most common bite site was the hands. Severe envenoming is not frequent in these accidents.

Epidemiology of snakebite in a central region of Brazil.

The aim of this article is to acquire knowledge about the aspects of snakebite epidemiology in a central region of Brazil. From 1993 to 1995, 90 cases of Crotalinae (Bothrops and Crotalus genera) and two cases of Micrurus snakebite were attended to in a general hospital. Epidemiological information about 73 out of the 90 Crotalinae victims was prospectively collected from interviews with the patients and/or their companions. Data from medical records were obtained for the 17 remaining cases. The snakes of Bothrops, Crotalus, and Micrurus genera were responsible for 74, 24 and 2% of the accidents, respectively. Most of the Crotalinae accidents occurred from October to March (68%) and from 06:00 to 12:00 a.m. (93%). Males (89%) and patients between 20 and 30 years-old (27%) were the most common victims. The main bite sites were: foot (24%), leg (23%), hand (22%) and ankle (21%). Among the 73 interviewed Crotalinae victims, farm workers were bitten more frequently (53%). The accidents often occurred during work (59%), and 90% of the patients wore footwear, but 30% were wearing only sandals. Tourniquet, squeezing, suction of the bite site and magic blessing were attempted in 47, 38, 8 and 10% of cases, respectively.

Wolf spider bites in São Paulo, Brazil: a clinical and epidemiological study of 515 cases.

Data obtained from 515 victims of bites of wolf spiders (family Lycosidae) who were attended in Vital Brazil Hospital, São Paulo City, Brazil, in a 5-year period (1979-1983) were analysed. Bites were more frequent in males (56%). All age groups were involved. Foot and hand were the preferential sites of bite (79%), and pain, generally mild, was the predominant symptom (83%). No local necrosis, a severe complication described in the previous literature, was detected, suggesting that those old cases were due to misdiagnosed Loxosceles spider bites. Specific antivenom was employed in only three cases which is evidence that physicians do not consider wolf spider bites to be severe.

Snakebite by the bushmaster (Lachesis muta) in Brazil: case report and review of the literature.

The bushmaster (Lachesis muta) of Central and South America, the world's longest pit viper, is capable of injecting a large dose of potent venom when it bites. A 28-year-old man, bitten by a 1.82 m long L. m. muta in Brazil, developed pain and oedema at the bite site, nausea, vomiting, diarrhoea and sweating. There was peripheral neutrophil leucocytosis and evidence of fibrinogen consumption with secondary activation of the fibrinolytic system. Two hours after the bite, eight ampoules of Instituto Butantan Lachesis antivenom was administered, and haemostasis was normal 24 hr later. A review of reports of 20 cases of bites in humans reliably attributed to this snake in Costa Rica, French Guiana, Brazil, Colombia and Venezuela confirms a syndrome of nausea, vomiting, abdominal colic, diarrhoea, sweating, hypotension, bradycardia and shock, possibly autopharmacological or autonomic in origin, not seen in victims of other American crotaline snakes. These, and other symptoms of bushmaster envenoming, are explained by haemorrhagic, coagulant and neurotoxic venom activities. The therapeutic efficacy of non-specific Bothrops/Crotalus polyvalent antivenoms in these cases has been unimpressive. For the treatment of bites by a snake which potentially injects a large dose (> 300 mg dry weight) of venom with a range of life-threatening activities, there is an urgent need to develop more potent specific antivenoms and to treat the dramatic and life-threatening cardiovascular symptoms.

Microbiological studies of abscesses complicating Bothrops snakebite in humans: a prospective study.

Forty patients with abscesses at the site of Bothrops bite were evaluated. Ten brought the snake responsible for the bite, Bothrops jararaca in all cases. On admission a sample was collected from each case for aerobic and anaerobic culture, and no abscesses drained spontaneously. None of the patients had received antibacterial therapy at this time. The bacteria most frequently isolated were Morganella morganii (23 patients), Providencia rettgeri (7) Enterobacter sp. (4), Escherichia coli (3), group D streptococcus (11) and Bacteroides sp. (6). All enterobacteria tested were sensitive to chloramphenicol, aminoglycosides and cefotaxime. Group D streptococci were sensitive to chloramphenicol, ampicillin and penicillin G, whereas anaerobic bacteria were sensitive to chloramphenicol and tetracycline. These results suggest that in cases of abscess formation secondary to Bothrops bite, chloramphenicol alone is a good choice, being both safe and cheap.

A biolistic process for in vitro gene transfer into chicken embryos.

Chicken embryos kept in culture medium were bombarded using a high helium gas pressure biolistic device. To optimize the factors that affect transformation efficiency, the lacZ gene under control of the human cytomegalovirus immediate early enhancer/promoter was used as a reporter gene. There was an inverse relationship between survival rate and transformation efficiency. The best conditions obtained for high embryo survival and high transformation efficiency were achieved with 800 psi helium gas pressure, 500 mmHg vacuum, gold particles, an 8 cm DNA-coated microparticle flying distance to the embryo and embryo placement 0.5 cm from the center of the particle dispersion cone. Under these conditions, transformation efficiency was 100%, survival rate 25% and the number of expression units in the embryo body cells ranged from 100 to 1,000. Expression of green fluorescent protein was also detected in embryos bombarded under optimal conditions. Based on the results obtained, the biolistic process can be considered an efficient method for the transformation of chicken embryos and therefore can be used as a model system to study transient gene expression and tissue-specific promoters.

[The epidemiology and clinical picture of an accidental bite by the South American rattlesnake (Crotalus durissus)]. / Epidemiologia e quadro clínico do acidente por cascavel sul-americana (Crotalus durissus).

Under study were two hundred and forty-nine cases of accidents caused by South American rattlesnakes (Crotalus durissus) admitted to the Vital Brasil Hospital, São Paulo, Brasil, from 1974 to 1990. The accidents were more common in the afternoon, from January to April and from October to December. Ninety nine out of 100 snakes classified as subspecies were C. d. terrificus. Most of the patients were males (80.7%). The inferior and superior limbs were bitten in 66.4% and 29.2% of the cases, respectively. The more frequent clinical manifestations were pain (61.0%) and edema (55.0%) at site of the bite, palpebral ptosis (75.9%), darkening of the urine due to myoglobinuria (38.6%) and myalgia (36.1%). Nine (3.6%) out of 32 patients with acute renal failure were submitted to dialysis, three presented respiratory failure treated with intubation and/or tracheotomy and one presented an ischemic cerebral stroke. Alteration of the blood coagulation was present in 48.1% of the patients. The blood picture of some patients several hours after the accident showed leucocytosis with a left shift and a tendency to normal values with eosinophilia. Serum creatine kinase activity was increased in 20 of 21 patients, with higher values 24 hours after the bite reaching 2,377 times the reference value. Lethality was 0.8%.

[Epidemiology and clinical picture of accidents by adult and young snakes Bothrops jararaca]. / Epidemiologia e quadro clínico dos acidentes por serpentes Bothrops jararaca adultas e filhotes.

Four hundred and fifteen cases of bites by adult Bothrops jararaca (group A) were admitted to the Hospital Vital Brasil between 1981 and 1987. These cases were compared to 562 cases of bites by young snakes of the same species (group B) during the same period and at the same hospital. In group B blood incoagulability was more frequent when compared to group A. However in group A bites in the leg, use of tourniquet, tecidual damage (blister, necroses and abscess), were more frequent when compared to group B. The doses of sero given for the group A was greater when compared to group B. Accidents month distribution, dates available were for the patients admitted between 1975 and 1988. The accidents were more frequent in the first and at the end of the year. In the first months of the year for the young snakes and mainly at the end of the year for the adult snakes.

[Assessment of the efficacy of antivenom injection at the site of the intramuscular inoculation of Bothrops jararaca venom: experimental study in mice]. / Avaliação da eficácia do antiveneno botrópico administrado no local da inoculação intramuscular do veneno de Bothrops jararaca: estudo experimental em camundongos.

The 50% effective intraperitoneal (ip) dose of Bothrops jararaca antivenom (ED50) was assessed in mice immediately (ED50 Oh) and thirty minutes (ED50 30') after the intramuscular (im) injection of two 50% lethal dose (LD50) of Bothrops jararaca venom. The efficacy of the antivenom injected at the venom inoculation site was assessed by the inoculation of two LD50 of the venom by im route, followed immediately (ED50 Oh) and 30 minutes later (ED50 30') by administration of the ED50 of the antivenom either entirely by the ip route or 50 percent ip plus 50 percent im, at the same inoculation site. It was shown that the ED50 30' was 3 times greater, than the ED50 Oh and that the antivenom was more protective to mice (lower death rate in 48 hours) when given entirely ip. It was concluded that, in this experimental model, a higher dose of bothropic antivenom is needed when the treatment is started lately, and that there is no benefit in its administration at the venom inoculation site.