Single-phase CT angiography predicts ASPECTS decay and may help determine when to repeat CT before thrombectomy.

OBJETIVES: Time is relative in large-vessel occlusion acute ischemic stroke (LVO-AIS). We aimed to evaluate the rate of inter-hospital ASPECTS decay in patients transferred from a primary (PSC) to a comprehensive stroke center (CSC); and to identify patients that should repeat computed tomography (CT) before thrombectomy. MATERIALS AND METHODS: This was a retrospective cohort study of consecutive anterior circulation LVO-AIS transferred patients. The rate of ASPECTS decay was defined as (PSC-ASPECTS - CSC-ASPECTS)/hours elapsed between scans. Single-phase CT angiography (CTA) at the PSC was used to classify the collateral score. We compared patients with futile versus useful CT scan re-evaluation. RESULTS: We included 663 patients, of whom 245 (37.0%) repeated CT at a CSC. The median rate of ASPECTS decay was 0.4/h (0.0-0.9). Patients excluded from thrombectomy after a CT scan repeat (n=64) had a median ASPECTS decay rate of 1.18/h (0.83-1.61). Patients with absent collateral circulation had a median rate of 1.51(0.65-2.19). The collateral score was an independent predictor of the ASPECTS decay rate (aß = -0.35; 95%CI -0.45 - -0.19, p<0.001). Age (aOR: 1.04 95% CI 1.02-1.07, p<0.001), NIHSS (aOR: 1.11 95% CI 1.06-1.15, p<0.001), PSC ASPECTS (aOR: 0.74 95% CI 0.60-0.91, p=0.006) and the CTA collateral score (aOR: 0.14 95% CI 0.08-0.22, p<0.001) were independent predictors of the usefulness of a CT scan repeat. CONCLUSIONS: The rate of ASPECTS decay can be predicted by the CTA collateral score, helping in the selection of patients that would benefit from repeating a CT assessment on arrival at the CSC.

An Origin of Citations: Darwin's Collaborators and Their Contributions to the Origin of Species.

In the first edition of the Origin of Species (1859), Charles Darwin apologized for not correctly referencing all the works cited in his magnum opus. More than 150 years later we have catalogued these citations and analyzed the resultant data. Looking for a complete selection of collaborators, a flexible interpretation of the term citation was necessary; we define it as any reference made to a third party, independently of its form or function. Following the same idea, the sixth edition of the Origin, originally published in 1872 and reprinted with minor additions and corrections in 1876, was chosen for the research because it represents the end of a long debate between Darwin and his peers. It naturally is the edition with the greatest number of citations and collaborators. Through a diverse theoretical analysis, we aim to present a new perspective for the study of the Origin of Species: a bibliographic approach that provides the tools needed to understand the history of the book as a physical and cultural object. Bibliometrics provides a theory of citations as well as a quantitative analysis; science studies highlights the profound social aspects of science in the making. The analysis resulted in 639 citations to 298 collaborators and provided a new perspective of the rhetorical structure of the Origin, even though these results are only the tip of the iceberg of the potential of all the data gathered in this study.

Blood Pressure Variability in Acute Ischemic Stroke: The Role of Early Recanalization.

We performed a retrospective study with the aim of investigating the association between blood pressure (BP) variability in the first 24 h after ischemic stroke and functional outcome, regarding arterial recanalization status. A total of 674 patients diagnosed with acute stroke and treated with revascularization therapies were enrolled. Systolic and diastolic BP values of the first 24 h after stroke were collected and their variation quantified through standard deviation. Recanalization state was evaluated at 6 h and clinical outcome at 3 months was assessed by modified Rankin Scale. In multivariate analyses systolic BP variability in the first 24 h post-stroke showed an association with 3 months clinical outcome in the whole population and non-recanalyzed patients. In recanalyzed patients, BP variability did not show a significant association with functional outcome.

Cerebrovascular Dissemination in Time and Space as a Predictor of Cardioembolism.

BACKGROUND: Cardioembolism has tendency to recur and cause lesions in distinct cerebrovascular territories. Using the imaging characteristics of cerebral lesions to determine dissemination in time and space (DTS) is a concept already used in other neurologic conditions; however, it has never been applied as a diagnostic tool in ischemic stroke etiology. AIM: This study aimed to assess DTS as a diagnostic marker of cardioembolism. METHODS: We enrolled consecutive patients with acute ischemic stroke of various etiologies admitted in a cerebrovascular disease nursery from a university hospital in a retrospective cohort study. We excluded patients with coexisting etiologies, incomplete study, or without an acute vascular lesion on computed tomography scan. Lacunar infarctions were not considered. Cerebrovascular territory was divided into right anterior, left anterior, and posterior. Localization of the acute vascular lesion(s), existence of previous vascular lesions, and their respective areas were analyzed. The presence of dissemination in time, space, or DTS was determined. RESULTS: We included 661 patients (mean age: 74.05 years (SD: 13.01)). Cardioembolism was the etiology with most DTS (30.47% of cardioembolic strokes); DT occurred more frequently within the atherosclerotic subtype (9.88%); DS was more prevalent within the arterial dissection group (3.33%). There was a statistically significant difference in stroke etiology between patients with DTS and patients without dissemination (P < .001). DTS had 81.67% specificity, 30.47% sensitivity, 66.67% positive predictive value, and 49.40% negative predictive value for the identification of cardioembolism. CONCLUSION: DTS is a specific diagnostic predictor of cardioembolic stroke and may be helpful in guiding etiologic investigation.

Recanalization Modulates Association Between Blood Pressure and Functional Outcome in Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: Historical stroke cohorts reported a U- or J-shaped relationship between blood pressure (BP) and clinical outcome. However, these studies predated current revascularization strategies, disregarding the recanalization state of the affected arterial territory. We aimed to investigate the relationship between BP in the first 24 hours after ischemic stroke and clinical outcome in patients submitted to intravenous or intra-arterial recanalization treatments. METHODS: Consecutive patients with acute stroke treated with intravenous thrombolysis or intra-arterial therapies were enrolled in a retrospective cohort study. BP was measured on regular intervals throughout day and night during the first 24 hours after stroke onset. The mean systolic BP and diastolic BP during the first 24 hours post stroke were calculated. Recanalization was assessed at 6 hours by transcranial color-coded Doppler, angiography, or angio-computed tomography. Functional outcome was assessed at 3 months by modified Rankin Scale. Linear and quadratic multivariate regression models were performed to determine associations between BP and functional outcome for the whole population and recanalyzed and nonrecanalyzed patients. RESULTS: We included 674 patients; mean age was 73.28 (SD, 11.50) years. Arterial recanalization was documented in 355 (52.70%) patients. In multivariate analyses, systolic BP and diastolic BP in the first 24 hours post stroke show a J-shaped relationship with functional outcome in the total population and in the nonrecanalyzed patients. Recanalyzed patients show a linear association with functional outcome (systolic BP: odds ratio, 1.015; 95% confidence interval, 1.007-1.024; P=0.001; R(2) change=0.001; P=0.412 and diastolic BP: odds ratio, 1.019; 95% confidence interval, 1.004-1.033; P=0.012; R(2) change<0.001; P=0.635). CONCLUSIONS: Systemic BP in the first 24 hours after ischemic stroke influences 3-month clinical outcome. This association is dependent on the revascularization status.

Different locations but common associations in subcortical hypodensities of presumed vascular origin: cross-sectional study on clinical and neurosonologic correlates.

BACKGROUND: Subcortical hypodensities of presumed vascular etiology (SHPVO) are a clinical, radiological and neuropathological syndrome with a still largely unexplained pathophysiology. Parallel to the clinical heterogeneity, there is also recognised cerebral topographical diversity with undetermined etiological implications. Our aim is to assess clinical and neurosonological predictors of SHPVO according to their location. METHODS: Cross sectional analysis of consecutive patients that underwent neurosonologic evaluation and head CT within one month, during a one year period. We excluded patients with absent temporal sonographic window, any pathology with a possible confounding effect on cerebral arterial pulsatility, atrial fibrillation and other etiologies of white matter diseases. The mean pulsatility index (PI) of both middle cerebral arteries was measured in the middle third of the M1 segment; intima media thickness was evaluated in the far wall of both common carotid arteries. SHPVO were rated by analysis of head CT in deep white matter (DWMH), periventricular white matter (PVWMH) and basal ganglia (BGH). We conducted a multivariate ordinal logistic regression model including all clinical, demographic and ultrasonographic characteristics to determine independent associations with SHPVO. RESULTS: We included 439 patients, mean age 63.47 (SD: 14.94) years, 294 (67.0%) male. The independent predictors of SHPVO were age (OR = 1.067, 95% CI: 1.047-1.088, p < 0.001 for DWMH; OR = 1.068, 95% CI: 1.049-1.088, p < 0.001 for PVWMH; OR = 1.05, 95% CI: 1.03-1.071, p < 0.001 for BGH), hypertension (OR = 1.909, 95% CI: 1.222-2.981, p = 0.004 for DWMH; OR = 1.907, 95% CI: 1.238-2.938, p = 0.003 for PVWMH; OR = 1.775, 95% CI: 1.109-2.843, p = 0.017 for BGH) and PI (OR = 17.994, 95% CI: 6.875-47.1, p < 0.001 for DWMH; OR = 5.739, 95%CI: 2.288-14.397, p < 0.001 for PVWMH; OR = 11.844, 95% CI: 4.486-31.268, p < 0.001 for BGH) for all locations of SHPVO. CONCLUSIONS: Age, hypertension and intracranial pulsatility are the main independent predictors of SHPVO across different topographic involvement and irrespective of extracranial atherosclerotic involvement.

Progranulin peripheral levels as a screening tool for the identification of subjects with progranulin mutations in a Portuguese cohort.

BACKGROUND: Progranulin (PGRN) mutations are associated with different clinical phenotypes, including frontotemporal lobar degeneration (FTLD), corticobasal syndrome (CBS) and Alzheimer's disease (AD). As all pathogenic PGRN mutations identified so far cause disease through haploinsufficiency, determination of PGRN levels has been proposed as a reliable method to identify mutation carriers. OBJECTIVE: To evaluate the accuracy of peripheral PGRN levels in the identification of the PGRN mutation carriers detected thus far in our Portuguese cohort. METHODS: Serum PGRN levels were measured in 244 subjects (124 patients in the spectrum of FTLD, 2 asymptomatic descendants of a FTLD patient, 56 AD patients and 64 controls) by a novel commercial ELISA kit. RESULTS: Low PGRN levels were detected in 7 individuals (5 behavioral variant frontotemporal dementia, 1 CBS, and 1 still clinically unaffected) that constituted the group of the null PGRN mutation carriers previously identified in our molecular diagnostic laboratory. The pathogenic mutations found consisted of 4 insertion-deletions, causing frameshifts resulting in premature stop codons, 3 of which were novel. In addition, a normal PGRN level was found in a patient harboring a novel missense variant. For this novel ELISA kit, we established a PGRN cut-off level that identified with 100% accuracy the pathogenic mutation carriers. CONCLUSION: This study supports the use of a novel assay for the determination of PGRN levels as a screening procedure to identify patients harboring null PGRN mutations. This approach would significantly decrease the required PGRN mutation analysis workload and should be extended to other clinical phenotypes than behavioral variant frontotemporal dementia and to apparently sporadic cases.

Recurrence in intracranial atherosclerotic disease: a stenosis-based analysis.

BACKGROUND: Intracranial atherosclerotic disease is a common cause of stroke; its incidence and prevalence vary widely by ethnicity. The aim of our study was to analyze the recurrence rate of cerebrovascular events in patients with symptomatic and asymptomatic intracranial stenosis (IS). METHODS: We conducted a historical cohort study including all patients admitted in our hospital for stroke or transient ischemic attack (TIA) during 2011 and 2012 with information on intracranial circulation (ultrasonography and/or computed tomography angiography). We identified patients with symptomatic and asymptomatic IS and studied the recurrence of cerebrovascular events (TIA or ischemic stroke within the territory of the stenosis) for a minimum follow-up period of 6 months after the diagnosis of IS. For the recurrence rate estimation, patients with other potentially embolic diseases (in cervical arteries or heart) were excluded. We calculated the rate of recurrence of cerebrovascular events and performed Kaplan-Meier survival curves for symptomatic and asymptomatic IS. RESULTS: We investigated 1302 patients, mean age was 72.41 years (standard deviation 12.75). We identified 218 IS in 158 patients, 77 were symptomatic and 141 were asymptomatic. The recurrence rate of cerebrovascular events was 12.32 per 100 patient-years, with a mean time to recurrence of 1.73 months for symptomatic intracranial stenosis (SIS) and .88 per 100 patient-years for asymptomatic IS (P < .001). CONCLUSIONS: These results indicate a high risk of early recurrence of stroke in the territory of a SIS, highlighting the importance of its early diagnosis and aggressive treatment.

Prevalence of sarcopenia in women at stable weight phase after Roux-en-Y gastric bypass.

Objective: Evaluating the prevalence of sarcopenia in women submitted to bariatric surgery - Roux-en-Y gastric bypass. Design: Observational, cross-sectional study. Subjects and methods: Women (18-65 years old) who underwent bariatric surgery (BG) ≥ 2 years and reached stable weight ≥ 6 months, were investigated. Control group (CG) comprised non-operated matched women with obesity. Body composition was determined through dual-energy X-ray absorptiometry. Low lean mass (LLM) was defined as appendicular lean mass index (ALM kg/height m2) < 5.5 kg/m2. Physical strength was assessed through dynamometer and sit-to-stand test (SST), whereas performance was assessed through 4-m gait speed and Short Physical Performance Battery Tests (SPPB). Sarcopenia was diagnosed in the presence of LLM and low strength. Results: One-hundred and twenty women (60 in each group, 50 ± 9.7 years old) were investigated. All anthropometric and body composition parameters were lower in BG than in CG, whereas strength and performance were similar between groups. Women with reduced strength presented high total fat mass and low physical activity level (p < 0.005). LLM was observed in 35% of BG and in 18.3% of CG (p = 0.04), whereas sarcopenia was diagnosed in 28.3% of BG and in 16.6% of CG (p = 0.12). Sarcopenic women in BG had better performance both in SST (p = 0.001) and SPPB (p = 0.004). Total lean mass (OR:1.41, 95% CI [1.18; 1.69], p < 0.001) and obesity (OR: 38.2 [2.27; 644.12], p < 0.001) were associated with sarcopenia in the multivariate analysis. Conclusion: Despite great weight loss, sarcopenia prevalence did not increase in BG and its presence was influenced by total lean mass and obesity.

Phospholipase A2 and Ischemic Stroke Etiology.

BACKGROUND: Lipoprotein-associated phospholipase A2 (Lp-PLA2), which is involved in the inflammatory atherosclerotic process, has emerged as an independent risk factor for atheromatous vascular events. Its impact on coronary disease has already been demonstrated, however, its influence in cerebrovascular etiology is still unknown. We aimed to observe and describe the potential association between Lp-PLA2 levels and the etiologic subtype of ischemic stroke. METHODS: Unicentric, observational, and prospective cohort study of consecutive patients with acute ischemic stroke, admitted in a comprehensive stroke center. Patients with incomplete investigation or coexisting causes were excluded. Lp-PLA2 was dosed in peripheral blood between day 3 and 14 postevent with "Lp-PLA2-SNIBE" kit. Statistical significance was set for P<0.05. RESULTS: A total of 96 patients were enrolled, with mean age of 75.31±11.88 years, 41 males (42.7%); 12.5% with lacunar stroke, 16.7% atherothrombotic, 46.9% cardioembolic, and 24% embolic stroke of undetermined source (ESUS). The level of Lp-PLA2 was different between etiologies (F=2.982, P=0.035), being lower in ESUS (143.3±42.8 ng/mL). There were no significant associations with previous vascular risk factors, history of ischemic stroke and modified-Rankin scale (mRS) score 3 months postevent. In ESUS patients, Lp-PLA2 was not associated with cervical ultrasound findings or frequent supraventricular extrasystoles. CONCLUSIONS: Lp-PLA2 levels are different between etiologic subtypes of ischemic stroke, being lower in ESUS patients. The results of this study reinforce the existence of distinct pathophysiological mechanisms in patients with ESUS. Multicenter clinical trials with larger sample sizes are needed to clarify the role Lp-PLA2 on the etiology of stroke.

Pathophysiology of Blood-Brain Barrier Permeability Throughout the Different Stages of Ischemic Stroke and Its Implication on Hemorrhagic Transformation and Recovery.

The blood-brain barrier (BBB) is a dynamic interface responsible for maintaining the central nervous system homeostasis. Its unique characteristics allow protecting the brain from unwanted compounds, but its impairment is involved in a vast number of pathological conditions. Disruption of the BBB and increase in its permeability are key in the development of several neurological diseases and have been extensively studied in stroke. Ischemic stroke is the most prevalent type of stroke and is characterized by a myriad of pathological events triggered by an arterial occlusion that can eventually lead to fatal outcomes such as hemorrhagic transformation (HT). BBB permeability seems to follow a multiphasic pattern throughout the different stroke stages that have been associated with distinct biological substrates. In the hyperacute stage, sudden hypoxia damages the BBB, leading to cytotoxic edema and increased permeability; in the acute stage, the neuroinflammatory response aggravates the BBB injury, leading to higher permeability and a consequent risk of HT that can be motivated by reperfusion therapy; in the subacute stage (1-3 weeks), repair mechanisms take place, especially neoangiogenesis. Immature vessels show leaky BBB, but this permeability has been associated with improved clinical recovery. In the chronic stage (>6 weeks), an increase of BBB restoration factors leads the barrier to start decreasing its permeability. Nonetheless, permeability will persist to some degree several weeks after injury. Understanding the mechanisms behind BBB dysregulation and HT pathophysiology could potentially help guide acute stroke care decisions and the development of new therapeutic targets; however, effective translation into clinical practice is still lacking. In this review, we will address the different pathological and physiological repair mechanisms involved in BBB permeability through the different stages of ischemic stroke and their role in the development of HT and stroke recovery.

Endothelial Progenitor Cells influence acute and subacute stroke hemodynamics.

BACKGROUND: Endothelial Progenitor Cells (EPCs) are a circulating stem cell population with in vivo capacity of promoting angiogenesis after ischemic events. Despite the promising preclinical data, their potential integration with reperfusion therapies and hemodynamic evolution of stroke patients is still unknown. Our aim was to determine the association of EPCs with acute, subacute and chronic hemodynamic features. METHODS: In this prospective study, we included consecutive patients with ages between 18 and 80years and non-lacunar ischemic stroke within the territory of a middle cerebral artery. All patients were subject to hemodynamic evaluation by ultrasound at baseline, seven days and three months. We quantified cerebral blood flow (CBF) and assessed early recanalization and collateral flow. Hemorrhagic transformation was graded in Magnetic Resonance imaging performed at seven days. EPCs were isolated from peripheral venous blood collected in the first 24h and seven days, counted and submitted to functional in vitro tests. RESULTS: We included 45 patients with a median age of 70±10years. The angiogenic and migratory capacities of EPCs were associated with increased collateral flow in the acute stage and day seven CBF, without statistically significant associations with recanalization nor haemorrhagic transformation. The number of EPCs was not associated with any hemodynamic variable. CONCLUSIONS: The functional properties of EPCs are associated with acute and subacute stroke hemodynamics, with no effect on haemorrhagic transformation.

Endothelial progenitor cells enhance blood-brain barrier permeability in subacute stroke.

OBJECTIVE: To study the association among endothelial progenitor cells (EPCs), subacute blood-brain barrier (BBB) permeability, and clinical outcome after ischemic stroke, determining the micro RNAs of EPCs responsible for good clinical outcome. METHODS: We included consecutive patients with nonlacunar acute ischemic strokes in the territory of a middle cerebral artery and ages between 18 and 80 years. Clinical outcome was defined as modified Rankin Scale score at 3 months. Neuroimaging was performed at day 0 and 7 by MRI, including assessment of BBB permeability by dynamic contrast enhancement. EPCs were isolated from peripheral venous blood, quantified, and submitted to in vitro functional tests, including migratory and angiogenic assays. Stroke hemodynamics were evaluated serially by ultrasound. Statistical significance was set at p < 0.05. RESULTS: We included 45 patients; mean age was 70.0 ± 10.0 years. The in vitro functional properties of EPCs were associated with BBB permeability, particularly at day 7. The number of each EPC subset at both timepoints was not associated with BBB permeability. Permeability of BBB at day 7 was independently associated with improved clinical outcome (odds ratio 0.897; 95% confidence interval 0.816-0.986; p = 0.025). The EPCs (CD34+ cell subset) of patients with good clinical outcome showed 24 differentially expressed miRNAs, with a common effect on adherens junction pathway. CONCLUSIONS: The functional properties of EPCs are associated with enhanced subacute permeability of BBB and improved clinical outcome after acute ischemic stroke.

Prevalence of sarcopenia in women at stable weight phase after Roux-en-Y gastric bypass

ABSTRACT Objective: Evaluating the prevalence of sarcopenia in women submitted to bariatric surgery - Roux-en-Y gastric bypass. Design: Observational, cross-sectional study. Subjects and methods: Women (18-65 years old) who underwent bariatric surgery (BG) ≥ 2 years and reached stable weight ≥ 6 months, were investigated. Control group (CG) comprised non-operated matched women with obesity. Body composition was determined through dual-energy X-ray absorptiometry. Low lean mass (LLM) was defined as appendicular lean mass index (ALM kg/height m2) < 5.5 kg/m2. Physical strength was assessed through dynamometer and sit-to-stand test (SST), whereas performance was assessed through 4-m gait speed and Short Physical Performance Battery Tests (SPPB). Sarcopenia was diagnosed in the presence of LLM and low strength. Results: One-hundred and twenty women (60 in each group, 50 ± 9.7 years old) were investigated. All anthropometric and body composition parameters were lower in BG than in CG, whereas strength and performance were similar between groups. Women with reduced strength presented high total fat mass and low physical activity level (p < 0.005). LLM was observed in 35% of BG and in 18.3% of CG (p = 0.04), whereas sarcopenia was diagnosed in 28.3% of BG and in 16.6% of CG (p = 0.12). Sarcopenic women in BG had better performance both in SST (p = 0.001) and SPPB (p = 0.004). Total lean mass (OR:1.41, 95% CI [1.18; 1.69], p < 0.001) and obesity (OR: 38.2 [2.27; 644.12], p < 0.001) were associated with sarcopenia in the multivariate analysis. Conclusion: Despite great weight loss, sarcopenia prevalence did not increase in BG and its presence was influenced by total lean mass and obesity.

Epitope mapping of recombinant Leishmania donovani virulence factor A2 (recLdVFA2) and canine leishmaniasis diagnosis using a derived synthetic bi-epitope.

BACKGROUND: Leishmaniasis is one of the most important zoonotic diseases spread in Latin America. Since many species are involved in dog infection with different clinical manifestations, the development of specific diagnostic tests is mandatory for more accurate disease control and vaccine strategies. METHODOLOGY/PRINCIPAL FINDINGS: Seventy-five 15-mer peptides covering the sequence of recombinant Leishmania donovani virulence factor A2 (recLdVFA2) protein were prepared by Spot synthesis. Membrane-bound peptides immunoreactivity with sera from dogs immunized with recLdVFA2 and with a specific anti-recLdVFA2 monoclonal antibody allowed mapping of continuous B-cell epitopes. Five epitopes corresponding to the N-terminal region of recLdVFA2 (MKIRSVRPLVVLLVC, RSVRPLVVLLVCVAA, RPLVVLLVCVAAVLA, VVLLVCVAAVLALSA and LVCVAAVLALSASAE, region 1-28) and one located within the repetitive units (PLSVGPQAVGLSVG, regions 67-81 and 122-135) were identified. A 34-mer recLdVFA2-derived bi-epitope containing the sequence MKIRSVRPLVVLLVC linked to PLSVGPQAVGLSVG by a Gly-Gly spacer was chemically synthesized in its soluble form. The synthetic bi-epitope was used as antigen to coat ELISA plates and assayed with dog sera for in vitro diagnosis of canine visceral leishmaniasis (CVL). The assay proved to be highly sensitive (98%) and specific (99%). CONCLUSIONS/SIGNIFICANCE: Our work suggests that synthetic peptide-based ELISA strategy may be useful for the development of a sensitive and highly specific serodiagnosis for CVL or other parasitic diseases.

2G ethanol from the whole sugarcane lignocellulosic biomass.

BACKGROUND: In the sugarcane industry, large amounts of lignocellulosic residues are generated, which includes bagasse, straw, and tops. The use of the whole sugarcane lignocellulosic biomass for the production of second-generation (2G) ethanol can be a potential alternative to contribute to the economic viability of this process. Here, we conducted a systematic comparative study of the use of the lignocellulosic residues from the whole sugarcane lignocellulosic biomass (bagasse, straw, and tops) from commercial sugarcane varieties for the production of 2G ethanol. In addition, the feasibility of using a mixture of these residues from a selected variety was also investigated. RESULTS: The materials were pretreated with dilute acid and hydrolyzed with a commercial enzymatic preparation, after which the hydrolysates were fermented using an industrial strain of Saccharomyces cerevisiae. The susceptibility to enzymatic saccharification was higher for the tops, followed by straw and bagasse. Interestingly, the fermentability of the hydrolysates showed a different profile, with straw achieving the highest ethanol yields, followed by tops and bagasse. Using a mixture of the different sugarcane parts (bagasse-straw-tops, 1:1:1, in a dry-weight basis), it was possible to achieve a 55% higher enzymatic conversion and a 25% higher ethanol yield, compared to use of the bagasse alone. For the four commercial sugarcane varieties evaluated using the same experimental set of conditions, it was found that the variety of sugarcane was not a significant factor in the 2G ethanol production process. CONCLUSIONS: Assessment of use of the whole lignocellulosic sugarcane biomass clearly showed that 2G ethanol production could be significantly improved by the combined use of bagasse, straw, and tops, when compared to the use of bagasse alone. The lower susceptibility to saccharification of sugarcane bagasse, as well as the lower fermentability of its hydrolysates, can be compensated by using it in combination with straw and tops (sugarcane trash). Furthermore, given that the variety was not a significant factor for the 2G ethanol production process within the four commercial sugarcane varieties evaluated here, agronomic features such as higher productivity and tolerance of soil and climate variations can be used as the criteria for variety selection.

First 'Rauisuchian' archosaur (Pseudosuchia, Loricata) for the Middle Triassic Santacruzodon assemblage zone (Santa Maria Supersequence), Rio Grande do Sul State, Brazil.

The 'Rauisuchia' are a group of Triassic pseudosuchian archosaurs that displayed a near worldwide distribution. In Brazil, their fossils are found only in the Santa Maria Formation (Paraná Basin) of the Rio Grande do Sul State, specifically in the Middle Triassic Dinodontosaurus assemblage zone (AZ) and the Late Triassic Hyperodapedon AZ (Rauisuchus tiradentes). Between these two cenozones is the Santacruzodon AZ (Middle Triassic), whose record was, until now, restricted to non-mammalian cynodonts and the proterochampsian Chanaresuchus bonapartei. Here we present the first occurrence of a rauisuchian archosaur for this cenozone, from the Schoenstatt outcrop, located near the city of Santa Cruz do Sul and propose a new species, based on biostratigraphical evidence and a comparative osteological analysis.

Kinetics of Gibberella fujikuroi growth and gibberellic acid production by solid-state fermentation in a packed-bed column bioreactor.

In this work the growth of Gibberella fujikuroi and gibberellic acid (GA3) production were studied using coffee husk and cassava bagasse as substrates in a packed-bed column bioreactor connected to a gas chromatograph for exit gas analysis. With the respirometric data, a logarithmic correlation between accumulated CO2 and biomass production was determined, and the kinetics of the fungal growth was compared for estimated and experimental data. The solid medium consisted of coffee husk (pretreated with alkali solution), mixed with cassava bagasse (7:3 dry weight basis), with a substrate initial pH of 5.2 and moisture of 77%. Cultivation was carried out in glass columns, which were packed with preinoculated substrate and with forced aeration of 0.24 L of air/[h (g of substrate)] for the first 3 days, and 0.72 L of air/[h (g of substrate)] for the remaining period. The maximum specific growth rate (microm) obtained was 0.052 h(-1) (between 24 and 48 h of fermentation). A production of 0.925 g of GA3/kg of substrate was achieved after 6 days of fermentation.

Gibberellic acid production by solid-state fermentation in coffee husk.

Five strains of Gibberella fujikuroi and one of Fusarium moniliforme were screened for the production of gibberellic acid (GA3) in coffee husk, and based on the results, one strain, G. fujikuroi LPB-06, was selected. The comparative production of GA3 by solid-state fermentation and submerged fermentation indicated better productivity with the former technique, mainly with pretreated substrate. The GA3 accumulation was 6.1 times higher in the case of solid-state fermentation. Considering the C:N relation, higher yields of GA3 were achieved using a mixed substrate comprising coffee husk and cassava bagasse (7:3, dry wt), increasing the results twice. Supplementation of an optimized saline solution containing 0.03% FeSO4 and 0.01% (NH4)2SO4 enhanced the accumulation of GA3 1.7 times in the fermented substrate. Under the finally optimized condition, the culture gave a maximum of 492.5 mg of GA3/kg of dry substrate, with a pH of 5.3, moisture of 75%, and incubation temperature of 29 degrees C. GA3 yield was almost 13 times more than the initial results.